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TMS320C54x Assembly Language Tools User's Guide

1. 23 iud Set symbol NSYMS equal to the symbol KR 24 EA INDEX and use it as you would INDEX ER 25 ck ck ck ck 0k ck Sk ck ck kk ck ck ck ck ck ck ck Ck ck ck ck ck ck ck ck ck ck ck kk ck kk ok kk ck Sk Sk Mk ko ko kv kx ok 26 0035 NSYMS GL INDEX 27 000005 0035 word NSYMS Assembler Directives 4 81 Space bes Reserve Space Syntax Description Example 4 82 space size in bits bes size in bits The space and bes directives reserve size number of bits in the current sec tion and fill them with Os When you use a label with the space directive it points to the first word reserved When you use a label with the bes directive it points to the Jastword reserved This example shows how memory is reserved with the space and bes directives 1 ck ck ck ck 0k ck ck 0k ck kk ck ck Ck ck 0k 0k ck kc ck Ck ck ck Ck ck ck ckock ck ck ck kk ok kk ck kv Sk kv kv ko ko 2 Begin assembling into text section Ae 3 4 000000 text 5 6
2. 0000004 bss ARRAY 100 1 ck ck ck kk kk ck ck ck ck ck ck ck ck 0k 0k 0k 0k 0k ck kk ke kk ko kk ko Sk Sk Sk kx kx X Assemble more code into text ae 000005 8000 STL A Var 1 KKK ck ck ck ck ck Ck Ck ck ck ck KKK ck kk Ck ck ck ck ck kk ko ck ck ck ko ko kk KK kx ko ko KKK Declare external bss symbols KE global ARRAY TEMP end Syntax Description Example Initialize Bytes byte byte value values ubyte value values Char value Valuen uchar value values The byte ubyte char and uchar directives place one or more bytes into consecutive words of the current section Each byte is placed in a word by itself the 8 MSBs are filled with Os A value can be _j Anexpression that the assembler evaluates and treats as an 8 bit signed or unsigned number A character string enclosed in double quotes Each character in a string represents a separate value Values are not packed or sign
3. 2 eo Equate symbol AUX R1 to register ARI ER 3 xu and use it instead of the register ak 4 D 0011 AUX_R1 Set AR1 6 000000 7711 STM 56h AUX R1 000001 0056 7 8 KKK ck ck ck KKK KKK KKK KK KKK KKK KKK KKK KKK ck ock ck ko ck ck KK KKK KKK 9 am Set symbol index to an integer expr TUR 10 mu and use it as an immediate operand FE 11 12 0035 INDEX equ 100 2 3 13 000002 F000 ADD INDEX A 000003 0035 14 15 16 Set symbol SYMTAB to a relocatable expr 17 ER and use it as a relocatable operand EK 18 19 000004 000A LABEL word 10 20 0005 SYMTAB set LABEL 1 21 22
4. MEMORY PAGE 0 ROM origin 2000h length 2000h PAGE 1 RAM origin 8000h length 8000h eR Re ee ee eR ee ee ee ee ke ke ke ke ke ke x f Specify the Output Sections ud SECTIONS data gt RAM PAGE 1 text ROM PAGE 0 bss gt RAM PAGE 1 Invoke the linker 1nk500 bttest cmd This creates an executable object file called bttest out use this new file as input for the absolute lister 8 6 Absolute Lister Example Step 3 Now invoke the absolute lister abs500 bttest out This creates two files called module1 abs and module2 abs module1 abs nolist array setsym 08000h dflag Setsym 08064h offset Setsym 08066h data setsym 08000h edata setsym 08000h text setsym 02000h etext setsym 02007h bss Setsym 08000h end setsym 08068h Setsect text 02000n Setsect data 08000n Setsect bss 08000h list bext Copy modulel asm module2 abs nolist array setsym 08000h dflag setsym 08064h offset Setsym 08066h data setsym 08000h edata setsym 08000h text Setsym 02000h etext Setsym 02007h bss Setsym 08000h end Setsym 0806
5. 35 global array 4 96 Reserve Uninitialized Space usect Figure 4 7 The usect Directive section var1 section var2 ptr array p 100 words 100 words 100 words reserved in var2 dflag 50 words 151 words reserved in var1 Assembler Directives 4 97 Var Use Substitution Symbols as Local Variables Syntax Description Var sym symo symg The var directive allows you to use substitution symbols as local variables within a macro With this directive you can define up to 32 local macro sub stitution symbols including parameters per macro The var directive creates temporary substitution symbols with the initial value of the null string These symbols are not passed in as parameters and they are lost after expansion For more information on macros see Chapter 5 Syntax Description Determine Device version Version value The version directive determines for which processor instructions are built Use one of the following for value 541 542 543 545 545LP 546LP 548 54 ext for all other C54x devices with extended program space Assembler Directives 4 99 Chapter 5 Macro Language The assembler supports a macro language that enables you to create your own instructions This is especially useful when a program exec
6. 4 000000 text 5 000000 E878 LD 78h A Assembled into text 6 000001 F000 ADD 36h A Assembled into text 000002 0036 7 8 Begin assembling into Vars section RN 9 10 000000 Sect Vars 11 0010 WORD LEN set 16 12 0020 DWORD LEN Set WORD_LEN 2 13 0008 BYTE LEN SO WORD LEN 2 14 ck ck ck ck ck ck ck 0k ck ck Ck ck kk ck Ck ck ck ck ck ck ck ck ck ck ck ck ck ck kk ck ck ck ck kk ok Pk Sk Sk kv Sk ko ok 15 Wok Resume assembling into text section 16 ok ck ck ck ck ck ck 0k ck ck Ck ck kk ck Ck ck ck ck ck ck ck ck ck ck ck ck ck ck kk ck kk ck kk ck Pk ko kv kv Sk kv ok 17 000003 text 18 000003 F000 ADD 42h A Assembled into text 000004 0042 19 000005 0003 byte 3 4 Assembled into text 000006 0004 20 21 Wok Re
7. 3 Assemble an initialized table into data 4 ck ck Ck ck ck 0k ck 0k ck Ck ck kk ck Sk 0k ck Ck ck ck ck ck kc ck ck ck ck ck ck ck ock ck ck kk ck Sk Sk Mk ko ko ko ko 5 000000 data 6 000000 0011 coeff word O011h 022h 033h 000001 0022 000002 0033 7 KKK KKK KKK KKK KKK KKK KKK KKK kc ck ck ck ck ck ck ck ook ck ck ck kk ck Sk KKK KA KK 8 E Reserve space in bss for a variable a 9 10 000000 bss buffer 10 1 3 ck ck ck Ck ck ck 0k ck 0k ck Ck ck ck Ck ck kk ck Ck ck ck ck ck kc ck ck ck ck ck ck ckock ck ck ck kk ck KKK ko ko ko ko 12 Still in data UK 13 14 000003 0123 ptr word 0123h 15 OK ck ck Kok ck 0k ck 0k ck Ck ck ck Ck ck 0k ck ck ck ck ck ck ck kc ck ck ck ck ck ck ck ock ck ck ok kk ck Sk Sk kv ko ko ko ko 16 Assemble code into the text section an 17 18 000000 text 19 00
8. 4 000000 data 5 000000 000a byte OAh OBh 000001 000b 6 7 8 Begin assembling into text section 9 ck ck ck ck ck ck 0k ck ck 0k ck ck ck ck Ck ck ck ck ck ck ck ck ck ck ck ck ck ck ck kk ck ko ko ke Sk kv ko ko kockok 10 000000 text 11 000000 0041 START string A p Cc 000001 0042 000002 0043 12 000003 0058 END String X Y mt 000004 0059 000005 005a 13 14 000006 0000 ADD START A 15 000007 0003 ADD END A 16 17 Resume assembling into data section 18 ck ck 0k ck ck oko Ck ck ok 0k ck kk ck Ck ck ck 0k ck Sk ck ck Ck ck ck ck ck ck ck ck kk kk kv kx ko kv kx ko 19 000002 data 20 000002 000c byte OCh ODh 000003 000d spi ck ck 0k ck ck ck ck kk ck 0k ck kk ck Ck ck ck ck ck Ck ck ck Ck ck kk ck kk ck kk ko Sk kv kx ko ko kx ko 22 Resume assembling into text section 23 24 000008 text 25 000008 0051 String Quit
9. 13 Wu Reserve 100 words in varl mE 14 15 000001 array usect varl 100 16 17 000001 F000 ADD 037h A Still in text 000002 0037 18 19 20 eur Reserve 50 words in varl 21 22 000065 dflag usect varl 50 23 24 000003 F000 ADD dflag A Still in text 000004 0065 25 26 27 yw Reserve 100 words in var2 Es 28 29 000000 vec usect var2 100 30 31 000005 F000 ADD vec A s Still an text 000006 0000 32 ck ck ck ck ck ck ck 0k ck ck Ck ck ck ck ck Ck ck ck ck ck ck ck ck ck ock ck ck ck kk ck ko ck ko Sk kv Mk ko ko ok 33 Declare an external usect symbol 34
10. 7 Reserve OFO bits 15 words in the 8 text section ak 9 KKK ck KKK KKK KKK KKK KKK KKK ck ck Ck ck ck ck ock KKK KKK KAKA KKK KKK HK 10 000000 SPace OFOh 11 00000f 0100 word 100h 200h 000010 0200 12 ck ck ck ck 0k ck ck 0k ck kk ck ck ck ck ck ck ck Ck ck ck 0k ck ck Sk ck ck ck ock ck ck ck kk ok ko ko kv Sk k kv ko ko ko 13 Begin assembling into data section kk 14 15 000000 data 16 000000 0049 string In data 000001 006E 000002 0020 000003 002E 000004 0064 000005 0061 000006 0074 000007 0061 ping KKK ck KK KKK KKK KKK KKK KK KKK ck kc ck ck ock kk ck kk KAKA KK KKK KK 18 Reserve 100 bits in the data section 19 des RES 1 points to the first word that AUR 20 AO contains reserved bits ni 21 22 000008 RES 1 Space 100 23 00000f 000F word 15 24 000010 0008 word RES_1 25 26 ck ck ck ck 0k ck ck 0k ck kk ck ck ck ck ck 0k ck Ck ck ck ck ck ck ck ck ck ck ock ck ck ck kk ok ko ko kv Sk KKK ko ko 27 Reserve 20 bits in the data section 28 RES 2 points to the last word that We 29 UR contains reserved bits uis 30 ck ck
11. building a hex command file for two 8 bit EPROMS 3 to generating a boot table to to C 24 image mode 10 26 to 10 27 invoking 10 3 to memory width 10 10 to 10 11 object formats 10 39 to 10 44 on chip boot loader 10 28 to 10 34 options 10 4 to ordering memory words 10 14 to 10 15 output filenames 10 24 ROM width 10 11 to 10 13 ROMS directive 10 16 to 10 21 SECTIONS directive 10 22 to 10 23 target width 10 10 hex500 command hexadecimal integer constants 3 16 hi assembler option high level language debugging defined Index 7 Index hole creating 66 to default fill value 7 11 defined fill value linker SECTIONS directive 7 33 filling 7 e8 to 7 69 7 69 in output S ME to 7 69 mee in uninitialized soot 7 69 i assembler option hex conversion utility option linker option 7 14 I MEMORY attribute 7 29 if directive use in macros image hex conversion nid option include directive 3 8 Lee include files 5 5 3 8 incremental linking defined E described 7 70 to 7 71 initialized section defined described initialized sections 2 7 input linker 7 3 7 25 to 7 26 section defined F 4 described to int directive 4 58 Intel object format 10 41 j linker option 7 16 k linker option 7 16 Index 8 keywords assembler option cross reference lister option linker option label case sensitivity E3 cross ref
12. I We S00B00004441544120492F4FF3 ze Sac ecor 1130000FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFCd4 1130010FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFED Data S31130020FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFDC Records 1130030F ECE S1130040FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFBC S9030000FC Termination E el Record Byte T Checksum Address Count 10 42 Description of the Object Formats 10 11 4 Texas Instruments SDSMAC Object Format t Option The TI Tagged object format supports 16 bit addresses It consists of a start of file record data records and end of file record Each of the data records is made up of a series of small fields and is signified by a tag character The sig nificant tag characters are Tag Character Description K followed by the program identifier 7 followed by a checksum 8 followed by a dummy checksum ignored 9 followed by a 16 bit load address B followed by a data word four characters F identifies the end of a data record followed by a data byte two characters Figure 10 13 illustrates the tag characters and fields in Tl Tagged object format Figure 10 13 Tl Tagged Object Format Start of file Load record Program address Tag characters identifier F1 WAT I1 F1 F1 F1 F1 r1 F1 FI F1 F1 KO00COFFTOTI90000BFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFF7EFS3DFE 37E BFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFFBFFFF7EE PEE E EE EE BEEREREEEE E EM
13. symbol def symbol symbol ref symbol symbol The global def and ref directives identify global symbols which are defined externally or can be referenced externally The def directive identifies a symbol that is defined in the current module and can be accessed by other files The assembler places this symbol in the sym bol table The ref directive identifies a symbol that is used in the current module but defined in another module The linker resolves this symbol s definition at link time The global directive acts as a ref or a def as needed A global symbol is defined in the same manner as any other symbol that is it appears as a label or is defined by the set bss or usect directive As with all symbols if a global symbol is defined more than once the linker issues a multiple definition error ref always creates a symbol table entry for a symbol whetherthe module uses the symbol or not global however creates an entry only if the module actually uses the symbol A symbol may be declared global for two reasons Ifthe symbol is not defined in the current module including macro copy and include files the global or ref directive tells the assembler that the symbolis defined in an external module This prevents the assembler from issuing an unresolved reference error At link time the linker looks for the symbol s definition in other modules Ifthe symbol is define
14. boot Make all sections bootable bootorg 0x0000 Place boot table in EPROM starting at address 0x0000 wy ROMS PAGE 0 ROM origin 0x0000 length 0x20000 In Example 3 memory width and ROM width are the same therefore the hex conversion utility creates a single output file The number of output files is determined by the ratio of memwidth to romwidth Example C 11 shows the map file boot2 map resulting from executing the command file in Example C 10 which includes the map option Hex Conversion Utility Examples C 15 Example 3 Generating a Boot Table Example C 11 Map File Resulting From the Command File in Example C 10 TMS320C54x Pru Oct 3d kk ck ck ck ck Ck Sk KKK ck Ck Ck ck ck KKK KKK KKK KKK ck ck ck ck kk kk ck kk ck kk ko kk KKK KKK KKK COFF Hex Converter Version x xx 15 27 46 2001 INPUT FILE NAME lt boot out gt OUTPUT FOR Default Default Default PHYSICAL MEMORY PARAMETERS BOOT LOADER PARAMETERS OUTPUT TRANSLATION MAP IAT Intel data width 16 memory width 8 MS gt LS output width 8 00000000 0001ffff Page 0 Memory Width 8 ROM Width 8 ROM OUTPUT FILES boot hex b0
15. lowercase L linker option The syntax for this option is l filename The filename is the name of an archive library the space between 1 and the filename is optional You can augment the linker s directory search algorithm by using the i linker option or the C DIR or C54X C DIR environment variables The linker searches for object libraries in the following order 1 It searches directories named with the i linker option 2 It searches directories named with C DIR and C54X C DIR 3 IfC DIRand C54X C DIR are notset it searches directories named with the assembler s environment variables C54X A DIR and A DIR 4 lt searches the current directory Linker Description 7 13 Linker Options 7 4 9 0 Name an Alternate Library Directory i Option The i option names an alternate directory that contains object libraries The syntax for this option is i dir The dir names a directory that contains object libraries the space between i and the directory name is optional When the linker is searching for object libraries named with the option it searches through directories named with i first Each i option specifies only one directory but you can use several i options per invocation When you use the i option to name an alternate directory it must precede the option on the command line or in a command file For example assume that there are two archive libraries called r lib and lib2 lib The ta
16. Note that the symbol refers to the current run address not the current load address of the section oy Expressions that decrement are illegal For example it is invalid to use the operator in an assignment to The most common operators used in assignments to are and align If an output section contains all input sections of a certain type such as text you can use the following statements to create a hole at the beginning or end of the output section text 100h Hole at the beginning data data 100h Hole at the end i Linker Description 7 67 Creating and Filling Holes 7 15 3 Filling Holes Another way to create a hole in an output section is to combine an uninitialized section with an initialized section to form a single output section n this case the linker treats the uninitialized section as a hole and supplies data for it The following example illustrates this method SECTIONS outsect filel obj text filel obj bss This becomes a hole Because the text section has raw data all of outsect must also contain raw data rule 1 Therefore the uninitialized bss section becomes a hole Uninitialized sections become holes only when they are combined with initialized sections If several uninitialized sections are linked together the resulting output section is also uninitialized When a hole exists in an initialized ou
17. The substitution symbol must be a valid symbol name The substitution symbol may be 32 characters long and must begin with a letter Remaining characters of the symbol can be a combination of alphanumeric characters the underscore and the dollar sign The eval directive performs arithmetic on substitution symbols which are stored in the substitution symboltable This directive evaluates the expression and assigns the string value of the result to the substitution symbol The eval directive is especially useful as a counter in loop endloop blocks L The well defined expression is an alohanumeric expression consisting of legal values that have been previously defined so that the result is an ab solute The substitution symbol must be a valid symbol name The substitution symbol may be 32 characters long and must begin with a letter Remaining characters of the symbol can be a combination of alphanumeric characters the underscore and the dollar sign Assign Character Strings to Substitution Symbols asg eval Example This example shows how asg and eval can be used als sslist show expanded sub symbols 2 3 asg eval example 4 5 asg INC 6 asg ARO FP 7 8 000000 000 ADD 100 A 000001 0064 9 000002 6d90 MAR FP MAR ARO 10 11 12 asg 0 x 135 loop 5 14 eval x 1 x 15 word x 16 endloop eval x 1 x eval O 1 x 000003 0001 word x word 1 eval x 1 x eval 141 x 000004 0002
18. asm500 input file object file listing file options asm500 input file object file listing file options is the command that invokes the assembler names the assembly language source file If you do not supply an extension the assembler uses the default extension asm unless the f assembler option is used If you do not supply an input filename the assembler prompts you for one The source file can contain mnemonic or algebraic instructions but not both The default instruction set is mnemonic To specify the algebraic instruction set use the mg option names the C54x object file that the assembler creates If you do not supply an extension the assembler uses obj as a default If you do not supply an object file the assembler creates a file that uses the input filename with the obj extension names the optional listing file that the assembler can create If you do not supply a listing file the assembler does not create one unless you use the lowercase L option or the x option In this case the assembler uses the input file name with a lst extension and places the listing file in the in put file directory If you supply a listing file but do not supply an extension the assembler uses st as the default extension identifies the assembler options that you want to use Options are not case sensitive and can appear anywhere on the com mand line following the assembler name
19. default tab size NOP NOP NOP tab 4 NOP NOP NOP tab 16 NOP NOP NOP Listing file 1 default tab size 2 000000 F495 NOP 3 000001 F495 NOP 4 000002 F495 NOP 5 7 000003 F495 NOP 8 000004 F495 NOP 9 000005 F495 NOP 10 12 000006 F495 NOP 13 000007 F495 NOP 14 000008 F495 NOP Assembler Directives 4 89 lext Assemble Into text Sections Syntax Description Example 4 90 text The text directive tells the assembler to begin assembling into the text section which usually contains executable code The section program counter is set to 0 if nothing has yet been assembled into the text section If code has already been assembled into the text section the section program counter is restored to its previous value in the section text is the default section Therefore at the beginning of an assembly the assembler assembles code into the text section unless you specify a different sections directive data or sect For more information about COFF sections see Chapter 2 Introduction to Common Object File Format This example assembles code into the text and data sections The data sec tion contains integer constants and the text section contains executable code T ck ck ck ck ck ck Ck ck ck 0k ck ck ck ck cock ck ck ck ck ck ck ck Ck ock ck ko ck kk sk Sk Sk Sk Sk ke ko ko ko 2 Begin assembling into data section 3
20. is an optional label for a member of the union This label is abso lute and equates to the present offset from the beginning of the union A label for a union member cannot be declared global is one of the following descriptors byte char double field float half int long short string ubyte uchar uhalt uint ulong ushort uword and word An element can also be a com plete declaration of a nested structure or union or a structure or union declared by its tag Following a union directive these directives describe the element s size They do not allocate memory is an optional expression for the number of elements described This value defaults to 1 A string element is considered to be one word in size and a field element is one bit is an optional label for the total size of the union 7 Note Directives That Can Appear in a union endunion Sequence The only directives that can appear in a union endunion sequence are ele ment descriptors structure and union tags conditional assembly directives and the align directive which aligns the member offsets on word bound aries Empty structures are illegal LILL M Assembler Directives 4 93 union endunion tag Declare Union Types Example 1 1 2 3 4 5 6 7 8 000000 9 10 11 000000 Example 2 4 94 YAO BWNE 0000 0000 0000 0002
21. newblock The newblock directive undefines any local labels currently defined Local labels by nature are temporary the newblock directive resets them and terminates their scope A local label is a label in the form n where n is a single decimal digit A local label like other labels points to an instruction word Unlike other labels local labels cannot be used in expressions Local labels are not included in the symbol table After a local label has been defined and perhaps used you should use the hewblock directive to reset it The text data and named sections also reset local labels Local labels that are defined within an include file are not valid out side of the local file Example declared again OB WNER 10 11 12 13 14 15 4 74 000000 000001 000002 000003 000004 000005 000006 000007 000008 000009 00000a 00000b 00000c 00000d 0076 1000 F010 0076 F843 0008 1000 F073 0009 1000 0000 F843 000D 8000 F495 This example shows how the local label 1 is declared reset and then ref ADDRA ADDRB ADDRC B Set 76h LABEL1 LD ADDRA A SUB B A BC 1 ALT LD ADDRB A B 2 1 LD ADDRA A 2 ADD ADDRC A newblock Undefine 1 to reuse BC 1 ALT STL A ADDRC 1 NOP Syntax Description Control Remarks noremark remark noremark num remark num The noremark directive suppresses the assembler remark identified by nu
22. Block repeat counter Block repeat start address Block repeat end address PMST register Data receive register 0 Data receive register Duplication of address values in the table supports the different names of the registers as they are implemented on different C54x devices Assembler Directives 4 71 mmregs Assign Memory Mapped Register Names as Global Symbols Table 4 2 Memory Mapped Registers Continued Name BDDRO DRR DXRO BDXR BDXRO DXR SPCO BSPC SPC BSPCE BSPCEO SPCE TIM PRD TCR PDWSR SWWSR IOWSR BSCR HPIC DRR1 TRCV DXR1 TDXR Hexadecimal Address 0020 0020 0021 0021 0021 0021 0022 0022 0022 0023 0023 0023 0024 0025 0026 0028 0028 0029 0029 002C 0030 0030 0031 0031 Description BSPO data receive register Data receive register Data transmit register 0 Data transmit register Data transmit register Data transmit register Serial port control register 0 Serial port control register Serial port control register BSP control extension register BSP control extension register BSP control extension register Timer register Period register Timer control register Program data S W wait state register Program data S W wait state register Bank switching control register Bank switching control register HPI control register Data receive register 1 Data receive register Data transmit register 1 Data transmit register Note Duplication of address values in the table
23. Storage class Dimensions D DC UD O DU O C L Section it was defined in Name or a pointer into the string table Basic type integer character etc Derived type array structure etc Line number of the source code that defined the symbol Section names are also defined in the symbol table All symbol entries regardless of class and type have the same format in the symbol table Each symbol table entry contains the 18 bytes of information listed in Table A 10 Each symbol may also have an 18 byte auxiliary entry the special symbols listed in Table A 11 on page A 16 always have an auxiliary entry Some symbols may not have all the characteristics listed above if a par ticular field is not set it is set to null Table A 10 Symbol Table Entry Contents Byte Number Type 0 7 Character 8 11 Long integer 12 13 Short integer 14 15 Unsigned short integer 16 Character 17 Character Description This field contains one of the following 1 An 8 character symbol name padded with nulls 2 A pointer into the string table if the symbol name is longer than 8 characters Symbol value storage class dependent Section number of the symbol Basic and derived type specification Storage class of the symbol Number of auxiliary entries always 0 or 1 Common Object File Format A 15 Symbol Table Structure and Content A 7 1 Special Symbols Table 4 11 A 16 The symbol table contains some speci
24. a symbol see Section 3 8 Symbols on page 3 19 or a combination of con stants and symbols in an expression see Section 3 9 Expressions on page 3 25 You must separate operands with commas E E Operand Prefixes for Instructions The assembler allows you to specify that a constant symbol or expres sion should be used as an address an immediate value or an indirect value The following rules apply to the operands of instructions B prefix the operand is an immediate value If you use the sign as a prefix the assembler treats the operand as an immediate value This is true even when the operand is a register or an address the assembler treats the address as a value instead of using the contents of the address This is an example of an instruction that uses an oper and with the prefix Label ADD 123 B The operand 123 is an immediate value The assembler adds 123 decimal to the contents of the specified accumulator B prefix the operand is an indirect address If you use the sign as a prefix the assembler treats the operand as an indirect address that is it uses the contents of the operand as an address This is an example of an instruction that uses an operand with the prefix Label LD AR4 A The operand AR4 specifies an indirect address The assembler goes to the address specified by the contents of register AR4 and then moves the contents of that location to the specified accumulator Immed
25. const vectors coeff and tables Suppose you want only text and data to be converted Use a SECTIONS directive to specify this SECTIONS text data To configure both of these sections for boot loading add the boot keyword SECTIONS text boot data boot 1 Note Using the boot Option and the SECTIONS Directive When you use the SECTIONS directive with the on chip boot loader the boot option is ignored You must explicitly specify any boot sections in the SECTIONS directive For more information about boot and other command line options associated with the on chip boot loader see Table 10 2 page 10 29 LLLLLLL Hex Conversion Utility Description 10 23 Output Filenames 10 7 Output Filenames When the hex conversion utility translates your COFF object file into a data format it partitions the data into one or more output files When multiple files are formed by splitting data into byte wide or word wide files filenames are always assigned in order from least to most significant This is true regardless of target or COFF endian ordering or of any order option 10 7 1 Assigning Output Filenames 10 24 The hex conversion utility follows this sequence when assigning output file names 1 It looks for the ROMS directive If a file is associated with a range in the ROMS directive and yo
26. 0000 0000 0000 0000 0002 These examples show unions with and without tags xample ival fval sval real_len employid size u global employid union word float string endunion bss employid real len tag xample ADD employid fval union long float word endunion A utag memberl int member2 float member3 string real len 2 allocate memory name an instance access union element utag memberl long member2 float member3 word real len 2 Syntax Description Reserve Uninitialized Space usect symbol usect section name size in words blocking flag alignment flag The usect directive reserves space for variables in an uninitialized named section This directive is similarto the bss directive both simply reserve space for data and have no contents However usect defines additional sections that can be placed anywhere in memory independently of the bss section symbol points to the first location reserved by this invocation of the usect directive The symbol corresponds to the name of the variable for which you re reserving space section name must be enclosed in double quotes This parameter names the uninitialized section The name can be up to 200 characters For COFF1 formatted files only the first 8 characters are significant A section name can contain a subsection name in the form section name subsection name siz
27. 00007c7 table 00007c80 00007fff FILL 000000ff Hex Conversion Utility Description 10 21 The SECTIONS Directive 10 6 The SECTIONS Directive 10 22 You can convert specific sections of the COFF file by name with the SECTIONS directive You can also specify those sections you want the utility to configure for loading from an on chip boot loader and those sections that you want to locate in ROM at a different address than the oad address speci fied in the linker command file DD Ifyou use a SECTIONS directive the utility converts only the sections that you list in the directive and ignores all other sections in the COFF file lf you don t use a SECTIONS directive the utility converts all initialized sections that fall within the configured memory The TMS320C54x compiler generated initialized sections include text const cinit and Switch Uninitialized sections are never converted whether or not you specify them in a SECTIONS directive Note Sections Generated by the C C Compiler The TMS320C54x C C compiler automatically generates these sections Initialized sections text const cinit and switch g Uninitialized sections bss stack and sysmem Use the SECTIONS directive in a command file For more information about using a command file see Section 10 3 Command Files on page 10 7 The general syntax for the SECTIONS directive is SECTIONS sname p
28. 1 2 Tools Descriptions 1222s kon a aspe ke Rond dec dee ew RE ede 1 3 Introduction to Common Object File Format sssss 2 1 Discusses the basic COFF concept of sections and how they can help you use the assembler and linker more efficiently Common object file format or COFF is the object file format used by the tools 24 GOFF FIle TYP S scccisuRe dew a YA E en RE Rd 2 2 GECO iii Sedo onore dol Ir ave Onan dawn Fd ea E SCR UE tu UA aoa 2 3 How the Assembler Handles Sections i 2 3 1 Uninitialized Sections aa eene 2 3 2 Initialized Sections 5 2 9 3 Named Sections cosdes boe eprRRE E RERRPRRREnIN PS saws ene ERR 2 3 4 Subsections ssrcsrrsriris ris idat Sri ENNEN ee 2 8 5 Section Program Counters 0 00 cet eens 2 3 6 An Example That Uses Sections Directives 2 4 How the Linker Handles Sections pp 2 4 4 Default Memory Allocation i 2 4 2 Placing Sections in the Memory Map i 2 5 RelocatiOn sa ia ma kareh Aiia e aaria E iaa Aa a a a e E a a a E Ar a 2 5 1 Relocation Issues sssrssssrisrrro riir ENEI eee 2 6 Runtime Relocation zsp eissii rreri a aa a e n 2 Loadimga Program xsecesx e eae cea de ced AKASA E EER 2 8 Symbols in a COFF File 2 0 0 ccc ee 2 8 1 External Symbols issus ded pete Syed bees du E Ree de End 2 8 2 The Symbol Table sen ee ee nh Assembler Description lessen hh hn Explains how to invoke the assembler and discusses source statement format valid co
29. 47 000019 ee03 FRAME 3 7 cycle 1 48 00001a fc00 RET cycle 2 49 branch occurs cycle 7 50 endfunc 9 000000000h 3 B 6 Syntax Description Example Define a Member member member name value type storage class size tag dims The member directive defines a member of a structure union or enumera tion ltis valid only when it appears in a structure union or enumeration defini tion LJ J Ll Name is the name of the member that is put in the symbol table The first 32 characters of the name are significant Value is the value associated with the member Any legal expression absolute or relocatable is acceptable Type is the C C type of the member Appendix A Common Object File Format contains more information about C C types Storage class is the C C storage class of the member Appendix A Common Object File Format contains more information about C C storage classes Size is the number of bits of memory required to contain this member Tagis the name of the type if any or structure of which this member is a type This name musthave been previously declared by a stag etag or utag directive Dims may be one to four expressions separated by commas This allows up to four dimensions to be specified for the member The order of parameters is significant The name and value are required parameters All other parameters may be omitted or empty Adjacent commas indicate an
30. End of file Data record words Checksum If any data fields appear before the first address the first field is assigned address 0000h Address fields may be expressed for any data byte but none is required The checksum field which is preceded by the tag character 7 is a 2s complement of the sum of the 8 bit ASCII values of characters beginning with the first tag character and ending with the checksum tag character 7 or 8 The end of file record is a colon Hex Conversion Utility Description 10 43 Description of the Object Formats 10 11 5 Extended Tektronix Object Format x Option The Tektronix object format supports 32 bit addresses and has two types of records data record contains the header field the load address and the object code termination record signifies the end of a module The header field in the data record contains the following information Number of ASCII Item Characters Description 96 1 Data type is Tektronix format Block length 2 Number of characters in the record minus the 96 Block type 1 6 data record 8 termination record Checksum 2 A 2 digit hex sum modulo 256 of all values in the record except the and the checksum itself The load address in the data record specifies where the object code will be located The first digit specifies the address length this is always 8 The remaining characters of the data record contain the obje
31. How the Linker Handles Sections 2 4 2 Placing Sections in the Memory Map Figure 2 3 illustrates the linker s default methods for combining sections Sometimes you may not want to use the default setup For example you may not want all of the text sections to be combined into a single text section Or you may want a named section placed where the data section would normally be allocated Most memory maps contain various types of memory RAM ROM EPROM etc in varying amounts you may want to place a section in a specific type of memory For further explanation of section placement within the memory map see Section 7 7 The MEMORY Directive on page 7 27 and Section 7 8 The SECTIONS Directive on page 7 32 Introduction to Common Object File Format 2 15 Helocation 2 5 Relocation The assembler treats each section as if it began at address O All relocatable symbols labels are relative to address 0 in their sections Of course all sections can t actually begin at address 0 in memory so the linker relocates sections by Allocating them into the memory map so that they begin at the appropriate address L Adjusting symbol values to correspond to the new section addresses Adjusting references to relocated symbols to reflect the adjusted symbol values The linker uses relocation entries to adjust references to symbol values The assembler creates a relocation entry each time a relocatable symbol is refer enced T
32. Intermediate files must have symbolic information By default the linker retains symbolic information in its output Do not use the s option if you plan to relink a file because s strips symbolic information from the output module Intermediate link steps should be concerned only with the formation of out put sections and not with allocation All allocation binding and MEMORY directives should be performed in the final link step If the intermediate files have global symbols that have the same name as global symbols in other files and you wish them to be treated as static visible only within the intermediate file you must link the files with the h option See subsection 7 4 7 Make All Global Symbols Static h and g global symbol Options on page 7 12 If you are linking C code don t use c or cr until the final link step Every time you invoke the linker with the c or cr option the linker will attempt to create an entry point The following example shows how you can use partial linking Step 1 Link the file filet com use the r option to retain relocation information in the output file tempout1 out 1nk500 r o tempoutl filel com file1 com contains SECTIONS sel fl obj 2 05 fn obj Partial Incremental Linking Step 2 Link the file file2 com use the r option to retain relocation information in the output file tempout2 out 1nk500 r o tempout2 file2 com file2 com contai
33. This redefines any previously defined macro library entry directive or instruction mnemonic that has the same name as the macro This allows you to expand the functions of directives and instructions as well as to add new instructions Defining Macros 5 2 Defining Macros You can define a macro anywhere in your program but you must define the macro before you can use it Macros can be defined at the beginning of a source file in an include copy file or in a macro library For more information about macro libraries see Section 5 4 Macro Libraries on page 5 14 Macro definitions can be nested and they can call other macros but all elements of any macro must be defined in the same file Nested macros are discussed in Section 5 9 Using Recursive and Nested Macros on page 5 22 A macro definition is a series of source statements in the following format macname macro parameter parametern model statements or macro directives mexit endm macname names the macro You must place the name in the source statement s label field Only the first 32 characters of a macro name are significant The assembler places the macro name in the internal opcode table replacing any instruction or previous macro definition with the same name macro identifies the source statement as the first line of a macro definition You must place macro in the opcode field parameters are optional substitution symbols that
34. To do this use the linker command shown in Example C 2 Example C 2 A Linker Command File for Two 8 Bit EPROMs test obj o test out m test map MEMORY PAGE 0 EXT PRG SECTIONS outsec secl sec2 org 0x1400 len OxEB80 gt EXT PRG PAGE 0 The EPROM programmer in this example has the following system require ments m d d d L m EPROM system memory width must be 16 bits ROM1 contains the upper 8 bits of a word ROMO contains the lower 8 bits of a word The hex conversion utility must locate code starting at EPROM address 0x0010 Intel format must be used Byte increment must be selected for addresses in the hex conversion utility output file memory width is the default Use the following options to set up the requirements of the system Option i byte memwidth 16 romwidth 8 Description Create Intel format Select byte increment for addresses in converted output file Set EPROM system memory width to 16 Set physical ROM width to 8 Example 1 Building a Command File for Two 8 B EPROMS With the memory width and ROM width values above the utility will automati cally generate two output files The ratio of memory width to ROM width deter mines the number of output files The ROMO file contains the lower 8 of the 16 bits of raw data and the ROM1 file contains the upper 8 bits of the correspond in
35. Usect section ushort directive 4 13 4 54 utag symbolic debugging directive uword directive v archiver option assembler option linker option var directive roba listing contr 4 17 variables local substitution symbols used as 5 13 Vectors 7 34 Version directive w linker option 7 19 W MEMORY attribute 7 29 well defined expression defined described width directive 4 18 listing control widths See memory widths wmsg directive listing control 4 17 4 41 Index 15 Index word defined word alignment Word directive limiting listing with option directive x archiver command assembler option 3 7 hex conversion utility option linker option X MEMORY attribute xfloat directive xlong directive xref500 command 9 3 Index 16
36. b Option 7 4 8 C Language Options c and cr Options i 7 4 4 Define an Entry Point e global symbol Option 4 Contents ix Contents 7 4 5 Set Default Fill Value Cf cc Option 0 eee ee 7 4 6 Make a Symbol Global g global symbol Option 7 4 7 Make All Global Symbols Static h Option pp 7 4 8 Define Heap Size heap constant Option pp 7 4 9 Alter the Library Search Algorithm l Option i Option and C54X C DIR C DIR Environment Variables llus 7 4 10 Disable Conditional Linking j Option pp 7 4 11 Ignore Alignment Flags Ck Option pp 7 4 12 Create a Map File m filename Option pp 7 4 13 Name an Output Module o filename Option pp 7 4 14 Specify a Quiet Run q Option pp 7 4 15 Strip Symbolic Information s Option i 7 4 16 Define Stack Size stack constant Option pp 7 4 17 Introduce an Unresolved Symbol u symbol Option 7 4 18 Specify a COFF Format v Option ssssssssssesessseeeeeee 7 4 19 Display a Message for Output Section Information w Option 7 4 20 Exhaustively Read Libraries x Option pp 7 5 Linker Command Files i 7 5 1 Reserved Names in Linker Command Files i 7 5 2 Constants in Command FileS 00sec eee 7 6 Object Libraries uoles bere cased RE RR AREA ELARTX REX C REA Rd 7 7 The MEMORY Directive 6 nn ee hn 7 7 1 Default Memory Model se 7 7 2 MEMORY Directive Syntax sieric
37. conditional expressions For more information about relational operators see subsection 3 9 4 Conditional Expressions on page 3 27 Assembly Time Symbol Directives 4 9 Assembly Time Symbol Directives Assembly time symbol directives equate meaningful symbol names to con stant values or strings The asgdirective assigns a character string to a substitution symbol The value is stored in the substitution symbol table When the assembler encounters a substitution symbol it replaces the symbol with its character string value Substitution symbols can be redefined asg 10 20 20 40 coefficients byte coefficients The eval directive evaluates an expression translates the results into a character and assigns the character string to a substitution symbol This directive is most useful for manipulating counters asg 1 x loop byte x 10h break x 4 eval x 1 x endloop The label directive defines a special symbol that refers to the loadtime address within the current section This is useful when a section loads at one address but runs at a different address For example you may want to load a block of performance critical code into slower off chip memory to save space and move the code to high speed on chip memory to run The set and equ directives set a value to a symbol The symbol is stored in the symbol table and cannot be refined For example bval Set 0100h byte bval bval 2 bval 12 B b
38. data bss bss The specification text means the unallocated text sections from all the input files This format is useful when You want the output section to contain all input sections that have a specified name but the output section name is different than the input sections name Lj You want the linker to allocate the input sections before it processes addi tional input sections or commands within the braces Linker Description 7 39 The SECTIONS Directive The following example illustrates the two purposes above SECTIONS text abc obj xqt text data data fil obj table In this example the text output section contains a named section xqt from file abc obj which is followed by all the text input sections The data section contains all the data input sections followed by a named section table from the file fil obj This method includes all the unallocated sections For example if one of the text input sections was already included in another output section when the linker encountered text the linker could not include that first text input section in the second output section 7 8 3 5 Allocation Using Multiple Memory Ranges The linker allows you to specify an explicit list of memory ranges into which an output section can be allocated Consider the following example MEMORY P_MEM1 origin 02000h length 01000h P MEM2 origin 04
39. data 1 00000080 00000000 UNINITIALIZED 00000080 00000000 boot obj data 00000080 00000000 rts lib exit obj data 00000080 00000000 boot obj data bss 1 00000080 00000025 UNINITIALIZED 00000080 00000004 boot obj bss 00000084 00000000 rts lib boot obj bss 00000084 00000021 exit obj bss const 1 00000080 00000000 UNINITIALIZED SYSmem 1 00000080 00000000 UNINITIALIZED Stack 1 000000a5 00000400 UNINITIALIZED 000000a5 00000000 rts lib boot obj stack GLOBAL SYMBOLS address name address name 00000080 bss 00000080 edata 00000080 data 00000080 data 00000400 STACK SIZE 00000080 array 0000145e _abort 00000080 bss 00000080 array 000000285 end 00001448 atexit 00000400 STACK SIZE 00001404 c int00 00001400 main 0000142f exit 00001404 c int00 00001400 main 0000142f exit 00001464 cinit 00001448 atexit 00000080 edata 0000145e abort 000000a5 end 00001464 cinit 12 symbols Hex Conversion Utility Examples C 13 Example 3 Generating a Boot Table Notice that the linker placed a hole at the end of the section boot sec with a fill value of 0 as specified in the command file Also the global symbol cinit coincides with the start of the first cinit section included in the link When the linker is executed with the command file in Example C 8 on page C 12 the linker issues warnings that the output file contains no text section and that the global symbol cinit is being redefined These warnings may be ignored
40. loop directive s optional expression evaluates to the loop count the number of loops to be performed If the expression is omitted the loop count defaults to 1024 unless the assembler encounters a break directive with an expression that is true nonzero For more information on the loop break endloop directives see page 4 66 The break directive and its expression are optional If the expression evaluates to false the loop continues The assembler breaks the loop when the break expression evaluates to true or when the break expression is omitted When the loop is broken the assembler continues with the code after the endloop directive Example 5 10 Example 5 11 and Example 5 12 show the loop break endloop directives properly nested conditional assembly directives and built in substitution symbol functions used in a conditional assembly code block Macro Language 5 15 Using Conditional Assembly in Macros Example 5 10 The loop break endloop Directives asg ly loop if x 10 H expression break x eval x 41 x endloop quit loop break with Example 5 11 Nested Conditional Assembly Directives asg 1 x loop if x 10 break 7 endif force break eval x 41 x endloop if x 10 quit loop Example 5 12 Built In Substitution Symbol Functions Used in a Conditional Assembly Code Block ref OPZ fcnolist Double Add or Subtract
41. no load address specified for using run address Description No load address is supplied for an initialized section If an ini tialized section has a run address only the section is allo cated to run and load at the same address no run allocation allowed for union member Description A UNION defines the run address for all of its members there fore individual run allocations are illegal no string table in file filename Description The input file may be corrupt Action If the input file is corrupt try reassembling it no symbol map produced not enough memory Description Available memory is insufficient to produce the symbol list This is a nonfatal condition that prevents the generation of the symbol list in the map file Linker Error Messages E 11 Linker Error Messages o flag does not specify a valid file name string Description The filename must follow the operating system file naming conventions origin missing for memory area Description An origin is not specified with the MEMORY directive An origin specifies the starting address of a memory range out of memory aborting Description Your system does not have enough memory to perform all required tasks Action Try breaking the assembly language files into multiple smaller files and do partial linking See Section 7 16 Partial Incre mental Linking on page 7 70 output file has no bss section Description This is a warni
42. objects that are 16 bits or larger start on a word boundary and are placed with the most significant bits at the lower address The C54x bss and usect directives have an additional flag called the alignment flag which specifies alignment on an even word boundary The C1x C2x C2xx C5x bss and usect directives do not use this flag The string directive for the C54xinitializes one character per word unlike the C1x C2x C2xx C5x assembler string which packs two characters per word The new pstring directive packs two characters per word as the former string did The following directives are new with the C54x assembler and are not supported by the C1x C2x C2xx C5x assembler Directive Usage Xfloat Same as float without automatic alignment Xlong Same as long without automatic alignment pstring Same as string but packs two chars word Directives That Define Sections 4 3 Directives That Define Sections These directives associate portions of an assembly language program with the appropriate sections J J bss reserves space in the bss section for uninitialized variables Clink sets the STYP_CLINK flag in the type field for the named section The clink directive can be applied to initialized or uninitialized sections The STYP CLINK flag enables conditional linking by telling the linker to leave the section out of the final COFF output of the linker if there are no references found to any symbol in t
43. 0 TMS320C545LP 000000 0 TMS320C546 000000 0 TMS320C546LP 000000 0 TMS320C548 000000 0 start 000000 1 ABC 000000 12 A 1 B 1 B 2 C e 2 far mode 000000 0 lflags 000000 0 start REF 9 11 Assembler Description 3 39 Chapter 4 Assembler Directives Assembler directives supply data to the program and control the assembly process Assembler directives enable you to do the following Assemble code and data into specified sections Reserve space in memory for uninitialized variables Control the appearance of listings Initialize memory Assemble conditional blocks Declare global variables Specify libraries from which the assembler can obtain macros Examine symbolic debugging information D O O D C UD LU LU This chapter is divided into two parts the first part Sections 4 1 through 4 10 describes the directives according to function and the second part Section 4 11 is an alphabetical reference Topic Page 43 Directives Summary x Ip te seers seers 4 2 Compatibility With the TMS320C1x C2x C2xx C5x Assembler Directives e ne co ro e LM Lee 4 8 4 3 Directives That Define Sections es 4 4 Directives That Initialize Constants ee 4 5 Directives That Align the Section Program Counter 4 6 Directives That Format the Output Listing 4 17 4 7 Directives That Reference Other Files s 4 8 Conditional Assembly Directives ee 4 9 Assembl
44. 0 for the blocking flag The assembler follows two rules when it allocates space in the bss section Rule1 Whenever a hole is left in memory as shown in Figure 4 5 the bss directive attempts to fill it When a bss directive is assembled the assembler searches its list of holes left by previous bss directives and tries to allocate the current block into one of the holes This is the standard procedure whether the contiguous al location option has been specified or not Rule2 Ifthe assembler does not find a hole large enough to contain the requested space it checks to see whether the blocking option is re quested Lj If you do not request blocking the memory is allocated at the current SPC If you request blocking the assembler checks to see whether there is enough space between the current SPC and the page boundary If there is not enough space the assembler creates another hole and allocates the space at the beginning of the next page Reserve Space in the bss Section bss The blocking option allows you to reserve up to 128 words in the bss section and ensure that they fit on one page of memory Of course you can reserve more than 128 words atatime butthey cannotfiton asingle page Thefollow ing example code reserves two blocks of space in the bss section memptr bss A 64 1 memptrl bss By 70 1 Each block must be contained within the boundaries of a single page after the first block is
45. 000006 F073 000007 0000 000008 000008 F7B9 000009 EAO0 00000a F4A7 00000b E837 00000c F6BB global RESET INTO INT1 INT2 global TINT RINT XINT USER global ISRO ISR1 ISR2 global time rcv xmt proc initmac macro initialize macro OVM 1 disable oflow DP 0 dp 0 ARP 7 arp ar7 A 037h acc 03fh INTM 0 enable ints endm Reset and interrupt vectors d ck ck 0k ck ck kc Ck ck ck 0k ck kk ck Ck ck ck ck ck ck ck ck kc ck ck ck KAKA KKK kv kx ko kx kx ko Sect reset RESET goto init INTO goto ISRO INTL goto ISR1 INT2 goto ISR2 Sect ints TINT goto time RINT goto rcv XINT goto xmt USER goto proc Ck Ck ck ck Ck ck ck ck ck Ck Sk ck Ck Sk ck Ck Sk ck kk ck ck ck ck ck ck kk ck kk kk ko KKK KKK KKK Initialize processor init initmac initialize macro OVM 1 disable oflow DP 0 dp 0 ARP 7 arp ar7 A 037h acc 03fh INTM 0 enable ints Field 1 3 36 Field 2 Field 3 Field 4 3 13 Cross Reference Listings Cros
46. 000009 0075 00000a 0069 00000b 0074 Syntax Description Example Define Page Title title itle string The title directive supplies a title that is printed in the heading on each listing page The source statement itself is not printed but the line counter is increm ented The string is a quote enclosed title of up to 65 characters If you supply more than 65 characters the assembler truncates the string and issues a warning The assembler prints the title on the page that follows the directive and on sub sequent pages until another title directive is processed If you want a title on the first page the first source statement must contain a title directive In this example one title is printed on the first page and a different title on succeeding pages Source file title Fast Fourier Transforms title Floating Point Routines page Listing file COFF Assembler Version x xx Copyright c 2001 Texas Instruments Incorporated Fast Fourier Transforms PAGE 1 2 3 4 H x COFF Assembler Version X xx Copyright c 2001 Texas Instruments Incorporated Floating Point Routines PAGE 2 Assembler Directives 4 91 union endunion tag Declare Union Type Syntax Description utag union expr mem element expr mem element expr mem tag utagn expri memy element exprw size endunion label tag utag The union direc
47. 0000c002 ARRAY 00000082 TEMP 00000182 end 00000182 edata 0000018a edata 00000082 end 0000c000 text 0000c011 etext 0000c011 etext 8 symbols 7 78 Chapter 8 Absolute Lister Description The absolute lister is a debugging tool that accepts linked object files as input and creates abs files as output These abs files can be assembled to produce alisting that shows the absolute addresses of object code Manually this could be a tedious process requiring many operations however the absolute lister utility performs these operations automatically Topic Page 8 1 Producing an Absolute Listing i B 2 8 2 Invoking the Absolute Lister 0 0c cece eee eee eee eee B 3 8 9MNMADSOIUteBIstenixampleeee B 5 8 1 Producing an Absolute Listing 8 1 Producing an Absolute Listing Figure 8 1 illustrates the steps required to produce an absolute listing Figure 8 1 Absolute Lister Development Flow Assembler First assemble a source file source file Link the resulting object file Invoke the absolute lister use the linked object file as input This creates a file with an abs extension Finally assemble the abs file you must invoke the assembler with the a option This Assembler produces a listing file that contains absolute addresses Absolute listing Invoking the Absolute Lister 8 2 Invoking the Absolute Lister The syntax for invoking the absolute lister is abs500 options in
48. 009 00a 00b 00c 00d 00e 00f 010 011 012 013 014 015 016 017 018 018 019 Ola Define a Function func endfunc Resulting assembly language code global power Sym func _power _power 36 2 0 3 gEORGRROECR OK ROCCO OR o eoo Re eoe o o o o ooo e ao do do oe o ooo e o oe dee oe FUNCTION DEF power pk kk kx x ke power eefd FRAME 1 3 495 nop 7 A assigned to _x Sym _x 0 4 17 16 Sym n 4 4 9 16 Sym _x 0 4 1 16 sym L1 1 4 1 106 sym _p 2 4 1 16 line 3 8000 STL A SP 0 line 5 7602 ST 1 SP 2 0001 line 6 7601 ST 1 SP 1 0001 7b8 SSBX SXM 495 nop 1004 LD SP 4 A 0801 SUB SP 1 A 843 BC L3 ALT 0018 branch occurs L2 line 7 4400 LD SP 0 16 A 3102 MPYA SP 2 8102 STL B SP 2 line 6 6501 ADDM 1 SP 1 0001 7b8 SSBX SXM 495 nop 1004 LD SP 4 A 0801 SUB SP 1 A 842 BC L2 AGEQ 000d branch occurs L3 line 8 1002 LD SP 2 A line 9 ee03 FRAME 3 fc00 RET return occurs endfunc 9 000000000n 3 Symbolic Debugging Directives B 5 ine Create a Line Number Entry Syntax ine ine number address Description The line directive creates a line number entry in the object file Line number
49. 24 illustrates the format of auxiliary table entries for arrays Note that multi dimensional arrays are limited to 4 dimensions This limitation can be avoided by using DWARF format compile with the gw shell option Table A 24 Array Format for Auxiliary Table Entries Byte Number 0 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Type Long integer Unsigned short integer Unsigned short integer Unsigned short integer Unsigned short integer Unsigned short integer Unsigned short integer A 7 8 7 End of Blocks and Functions Description Tag index line number declaration Size of array First dimension Second dimension Third dimension Fourth dimension Unused zero filled Table A 25 illustrates the format of auxiliary table entries for the ends of blocks and functions Table A 25 End of Blocks Functions Format for Auxiliary Table Entries Byte Number 0 3 4 5 6 17 Type Unsigned short integer Description Unused zero filled C source line number Unused zero filled A 7 8 8 Beginning of Blocks and Functions Symbol Table Structure and Content Table A 26 illustrates the format of auxiliary table entries for the beginnings of blocks and functions Table A 26 Beginning of Blocks Functions Format for Auxiliary Table Entries Byte Number 0 3 4 5 6 11 12 15 16 17 Type Unsigned short integer Long integer Description Unused zero filled C source line number Unused
50. 26 Expressions 3 9 3 Well Defined Expressions Some assembler directives require well defined expressions as operands Well defined expressions contain only symbols or assembly time constants thatare defined before they are encountered in the expression The evaluation of a well defined expression must be absolute Example 3 3 Well Defined Expressions data labell word word word label2 word X Set goodsyml set goodsym2 set goodsym3 set goodsym4 set 0 1 2 3 50h 100h X Because value of X is defined before referenced this is a valid well defined expression All references to previously defined local labell labels including the current SPC are considered to be well defined label2 labell Although labell and label2 are not absolute symbols because they are local labels defined in the same section their difference can be computed by the assembler The difference is absolute so the expression is well defined 3 9 4 Conditional Expressions The assembler supports relational operators that can be used in any expression they are especially useful for conditional assembly Relational operators include the following Equal to Equalto Notequalto lt Less than lt Less than or equal to gt Greater than gt Greater than or equal to Conditional expressions evaluate to 1 if true and 0 if false they can be used only on operands of equivale
51. 8 o file bO o file b1 romwidth 8 o file byt Hex Conversion Utility Description 10 13 Understanding Memory Widths 10 4 5 A Memory Configuration Example Figure 10 5 shows a typical memory configuration example This memory system consists of two 128K x 8 bit ROM devices Figure 10 5 C54x Memory Configuration Example Data width 16 bits Lower 8 bits data AABBh lt P Upper 8 bits data CPU AAh BBh 128K x8 128K x8 ROMO ROM1 foo 1 Source file tad nee word AABBh its its Le J System memory width 16 bits 10 4 6 Specifying Word Order for Output Words When memory words are narrower than target words memory width 16 tar get words are split into multiple consecutive memory words There are two ways to split a wide word into consecutive memory locations in the same hex conversion utility output file DD order MS specifies big endian ordering in which the most significant part of the wide word occupies the first of the consecutive locations DD order LS specifies little endian ordering in which the the least signifi cant part of the wide word occupies the first of the consecutive locations By default the utility uses little endian format because the C54x boot loaders expect the data in this order Unless you are using your own boot loader pro gram avoid using order MS 10 14 Understanding Memory Widths Note When th
52. 86 Intel Motorola Exorciser Motorola S supporting 16 bit 24 bit and 32 bit addresses Texas Instruments SDSMAC TI Tagged supporting 16 bit addresses D LDLDLUL Topic 10 1 Hex Conversion Utility Development Flow 10 2 Invoking the Hex Conversion Utility sees 10 3 Command Files sis cs en crete ciel te cies cles sie we rur TEE 10 4 Understanding Memory Widths 00 ccc cece eee eee 10 5 The ROMS Directive ro nelson eens ne ceteris 10 6 The SECTIONS Directive 7 5 ETT ls estes erate teeta 10 7 Output Filenames em ses tna en en cine donee ee denen eee 10 8 Image Mode and the fill Option Lees 10 9 Building a Table for an On Chip Boot Loader 10 10 Controlling the ROM Device Address 10 11 Description of the Object Formats 10 12 Hex Conversion Utility Error Messages Hex Conversion Utility Development Flow 10 1 Hex Conversion Utility Development Flow Figure 10 1 highlights the role of the hex conversion utility in the assembly language development process Figure 10 1 Hex Conversion Utility Development Flow C Source files Macro Source files C compiler Translator Archiver Assembler utility source Macro library Assembler source Library build utility Runtime Assembler CD s
53. ADDRB A otherwise load ADDRB To A B 2 and Branch to 2 1 LD ADDRA A 1 Load ADDRA To Accumulator A 2 ADD ADDRC A 2 Add ADDRC BC 1 ALT If less than 0 branch to 1 STL A ADDRC Store Acc low in ADDRC 1 OP WRONG 1 is multiply defined Local labels are especially useful in macros If a macro contains a normal label andis called more than once the assembler issues a multiple definition error If you use a local label and newblock within a macro however the local label is used and reset each time the macro is expanded Up to ten local labels of the n form can be in effect at one time Local labels of the form name are not limited After you undefine a local label you can define it and use it again Local labels do not appear in the object code symbol table The maximum label length is shortened to allow for the unique suffix If the macro is expanded fewer than 10 times the maximum label length is 126 char acters If the macro is expanded from 10 to 99 times the maximum label length is 125 Example 3 2 demonstrates the name form of a local label Assembler Description 3 23 Symbols Example 3 2 name Local Labels PR RR RRR KER KKK kk kk KEK KK KKK RK KEK KK KEK KKK KEK KKK KKK KEK koe kk ke ke x First definition of local label mylab LER RER ERIE R RON OR ORC deo o eec oe ode eo do coe Reo eode eoe oer nop mylab nop b mylab PR RR RRR KER KKK kk kk ke kk KK KKK RK KER
54. C language 8 4 2 4 but 8 4 2 1 Assembler Description 3 25 Expressions 3 9 1 Operators Table 3 1 lists the operators that can be used in expressions __ _____ a eee eee Note Differences in Precedence From Other TMS320 Assemblers Some other TMS320 processors use a different order of precedence than the TMS320C54x and occasionally different results may be produced from the same source code for this reason The C54x uses the same order of pre cedence as the C language Table 3 1 Operators Used in Expressions Precedence Symbols Operators Evaluation Unary plus minus 1s complement Right to left logical negation Multiplication division modulo Left to right Addition subtraction Left to right lt lt gt gt Left shift right shift Left to right lt lt gt gt Less than LT or equal greater than Left to right GT or equal Iz Not equal to equal to Left to right amp Bitwise AND Left to right Bitwise exclusive OR Left to right Bitwise OR Left to right Note Unary and have higher precedence than the binary forms 3 9 2 Expression Overflow and Underflow The assembler checks for overflow and underflow conditions when arithmetic operations are performed at assembly time It issues a Value Truncated warn ing whenever an overflow or underflow occurs The assembler does not check for overflow or underflow in multiplication 3
55. C 11 Example 3 Generating a Boot Table Example C 8 Linker Command File to Form a Single Boot Section l rts lib m bootl map o boot out MEMORY PAGE 0 PROG origin 001400h length 01000h PAGE 1 DATA origin 0080h length 01000h SECTIONS boot_sec text xf Set start address for C init table Pg xy cinit p Include all cinit sections X t ecrnit Reserve a single space for the zero word to mark end of C init Peg xy t 1 fill 0x0000 Make sure fill value is 0 load PROG PAGE 0 data DATA PAGE 1 bss gt DATA PAGE 1 const gt DATA PAGE 1 Sysmem DATA PAGE 1 Stack DATA PAGE 1 Example C 9 shows a portion of the map file generated when the linker is executed with this command file Example 3 Generating a Boot Table Example C 9 Section Allocation Portion of Map File Resulting From the Command File SECTION ALLOCATION MAP output attributes section page origin length input sections boot sec 0 00001400 0000006e 00001400 00000004 boot obj text 00001404 0000002b res Lib boot obj text 0000142f 00000035 exit obj text 00001464 00000006 boot obj cinit 0000146a 00000003 rts lib exit obj cinit 0000146d 00000001 HOLE fill 0000
56. Constant equal to 12049 or 007846 OFH Constant equal to 1549 or 000F16 37ACh Constant equal to 14 25219 or 37AC46 Or you can use C notation for hexadecimal constants 0x78 Constant equal to 12010 or 007816 OxOF Constant equal to 1549 or 000F46 0x37AC Constant equal to 14 25249 or 37AC46G 3 6 5 Character Constants 3 16 A character constant is a string of one or two characters enclosed in single quotes The characters are represented internally as 8 bit ASCII characters Two consecutive single quotes are required to represent each single quote that is part of a character constant A character constant consisting only of two single quotes is valid and is assigned the value 0 If only one character is speci fied the assembler right justifies the bits These are examples of valid charac ter constants a Represented internally as 6146 C Represented internally as 4346 D Represented internally as 2 74446 Constants Note the difference between character constants and character strings Section 3 7 Character Strings on page 3 18 discusses character strings Acharacter constant represents a single integer value a string is a list of char acters 3 6 6 Floating Point Constants A floating point constant is a string of decimal digits followed by an optional decimal point fractional portion and exponent portion The syntax for a floating point number is i nnn nnn Ele nnn J Replace nnn with a s
57. DT NON T NULL DT FCN See note 1 DT ARY See note 1 DT NON T VOID DT NON T VOID DT PTR T STRUCT DT ARR T UNION DT NON T ENUM Auxiliary Entry Format Filename see Table A 19 Section see Table A 20 Tag name see Table A 21 End of structure see Table A 22 Function see Table A 23 Array see Table A 24 Beginning and end of a block see Table A 25 and Table A 26 Beginning and end of a function see Table A 25 and Table A 26 Name related to a structure union or enumeration see Table A 27 In Table A 18 tagname refers to any symbol name including the special symbol nfake Fcname and arrname refer to any symbol name A symbol that satisfies more than one condition in Table A 18 should have a union format in its auxiliary entry A symbol that satisfies none of these condi tions should not have an auxiliary entry Common Object File Format A 23 Symbol Table Structure and Content A 7 8 1 Filenames Each of the auxiliary table entries for a filename contains a 14 character file name in bytes 0 13 Bytes 14 17 are unused Table A 19 Filename Format for Auxiliary Table Entries Byte Number Type Description 0 13 Character File name 14 17 Unused A 7 8 2 Sections Table A 20 illustrates the format of auxiliary table entries Table A 20 Section Format for Auxiliary Table Entries Byte Number Type Description 0 3 Long integer Section length 4 6 Unsigned short integer
58. KK KKK KKK EK ko ke kk ke kk KEK koe kk ke ke Include file has second definition of mylab PE REIFF IE REPRE FR de dee caede eoo eges BE APPR ues AR PIE deese a EP Fe copy aine iE REN ER ERE RENE A EAH RK IK OR KO OR ORC e o deo o ode ooo Re ao doe aee Third definition of mylab reset upon exit from include g HR RU ese ede oe de koe dece dee AE fede dese eode e ede de dede vea dee de ie RR ER de e oe deae mylab nop b mylab Fourth definition of mylab in macro macros use different namespace to avoid conflicts gQ We de oce eo LER ERNE LEK dese deese erae seo deo eaae eoe dece eror doceo eo oe aor mymac macro mylab nop b mylab endm PR RR RRR KERR KKK KKK KEK KK KKK RK KER KK KK KEK ke kk koc ke kc ko ke kk KEK koe kk ke ke k Macro invocation g WR fee AL ti EE AR RAR RRS RR ERR ER ele ae se RRR RR RR oe mymac ck ck ck ck ck ck KKK KKK KKK KKK KKK KKK KKK KK KKK KKK KEKKKKKKAKK KKK KAKA KKK KKK Reference to third definition of mylab note that definition is not reset by macro invocation nor conflicts with same name defined in macro KKK ck ck ck KKK KKK KKK KKK KKK KKK KKK KK KKK KKK KEK ck ck ck kc ck kk KKK KAKA KKK kx ko b mylab Ne Changing section allowing
59. Number of relocation entries 7 8 Unsigned short integer Number of line number entries 9 17 Not used zero filled A 7 8 3 Tag Names Table A 21 illustrates the format of auxiliary table entries for tag names Table A 21 Tag Name Format for Auxiliary Table Entries Byte Number Type Description 0 5 Unused zero filled 6 7 Unsigned short integer Size of structure union or enumeration 8 11 Unused zero filled 12 15 Long integer Index of next entry beyond this function 16 17 Unused zero filled A 7 8 4 End of Structure Symbol Table Structure and Content Table A 22 illustrates the format of auxiliary table entries for ends of structures Table A 22 End of Structure Format for Auxiliary Table Entries Byte Number 0 3 4 5 6 7 8 17 A 7 8 5 Functions Type Long integer Unsigned short integer Description Tag index Unused zero filled Size of structure union or enumeration Unused zero filled Table A 23 illustrates the format of auxiliary table entries for functions Table A 23 Function Format for Auxiliary Table Entries Byte Number 0 3 4 7 8 11 12 15 16 17 Type Long integer Long integer Long integer Long integer Description Tag index Size of function in bits File pointer to line number Index of next entry beyond this function Unused zero filled Common Object File Format A 25 Symbol Table Structure and Content A 7 8 6 Arrays Table A
60. PO ES PRR NF OW 13 14 15 16 17 18 19 20 21 23 24 25 26 27 28 000000 000001 000002 000003 0004 000a 0008 0005 Assemble Conditional Blocks SYMI SYM2 SYM3 SYM4 If TE If If 4 This example shows conditional assembly Set 1 Set 2 Set 3 Set 4 Lf SYMA byte SYMA else byte SYM2 endif if SYM1 byte 10 else byte SYM1 endif IT SYM3 byte SYM3 else byte SYM4 endif if SYM1 2 byte SYM1 elseif SYM2 byte SYM2 endif if elseif else endif SYM2 SYM2 Equal values SYM2 Unequal values z 10 Less than equal Greater than SYM2 SYM4 SYM2 SYM2 Unequal value SYM4 Equal values SYM3 5 SYM3 Assembler Directives 4 57 int uint word uword J nitialize 16 bit Integer Syntax Description int value valuen Uint value values word value values uword value Yvaluen The int uint word and uword directives are equivalent they place one or more values into consecutive 16 bit fields in the current section A valuecan be either Anexpression that the assembler evaluates and treats as an 16 bit signed or unsigned number D A character string enclosed in double quotes Each character in a string represents a separate value The valuescan be either absolute or relocatable expressions If an expression is relocatable the assembler generat
61. RefLn RefLn RefLn file2 asm EDEF 000000 000080 7 1 Symbol Z Filename RTYP AsmVal LnkVal DefLn RefLn RefLn RefLn file2 asm EDEF 000003 000003 9 i 9 4 Cross Reference Listing Example The terms defined below appear in the preceding cross reference listing Symbol Name Filename RTYP AsmvVal LnkVal DefLn RefLn Name of the symbol listed Name of the file where the symbol appears The symbol s reference type in this file The possible refer ence types are STAT The symbol is defined in this file and is not declared as global EDEF Thesymbolis defined in this file and is declared as global EREF The symbolis not defined in this file but is refer enced as a global UNDF The symbol is not defined in this file and is not declared as global This hexadecimal number is the value assigned to the symbol at assembly time A value may also be preceded by a character that describes the symbol s attributes Table 9 1 lists these characters and names This hexadecimal number is the value assigned to the symbol after linking The statement number where the symbol is defined Theline number where the symbol is referenced If the line number is followed by an asterisk then that reference may modify the contents of the object If the line number is followed by a letter such as A B or C the symbol is referenced in a file specified by a include directive in the assembly source A
62. SCNUM 3 bss section typical N SCNUM 4 32 767 Section number of a named section in the order in which the named sections are encountered If there were no text data or bss sections the numbering of named sections would begin with 1 If a symbol has a section number of 0 1 or 2 it is not defined in a section A section number of 2 indicates a symbolic debugging symbol which includes structure union and enumeration tag names type definitions and the filename A section number of 1 indicates that the symbol has a value but is not relocatable A section number of 0 indicates a relocatable external symbol that is not defined in the current file Bytes 14 15 of the symbol table entry define the symbol s type Each symbol has one basic type and one to six derived types Following is the format for this 16 bit type entry Derived Derived Derived Derived Derived Derived Type Type Type Type Type Type Ts 6 5 4 3 2 1 yp Size in bits 2 2 2 2 2 2 4 Bits 0 3 of the type field indicate the basic type Table A 16 lists valid basic types Common Object File Format A 21 Symbol Table Structure and Content Table A 16 Basic Types Mnemonic T NULL T CHAR T SHORT T INT T LONG T FLOAT T DOUBLE T STRUCT T UNION T ENUM T MOE T UCHAR T USHORT Value Qo Oo N Oo oO A CO PD mE c 0 12 13 Type Type not assigned Character Short integer Integer Long integer Floating
63. The linker provides a simple way to accomplish this You can use the SECTIONS directive to direct the linker to allocate a section twice once to set its load address and again to set its run address For example fir load ROM run RAM Use the oad keyword for the load address and the run keyword for the run address Refer to Section 2 6 Runtime Relocation on page 2 19 for an overview on runtime relocation Specifying Load and Run Addresses The load address determines where a loader will place the raw data for the section All references to the section such as labels in it refer to its run address The application must copy the section from its load address to its run address this does not happen automatically when you specify a separate run address If you provide only one allocation either load or run for a section the section is allocated only once and will load and run at the same address If you provide both allocations the section is allocated as if it were two sections of the same size This means that both allocations occupy space in the memory map and cannot overlay each other or other sections The UNION directive provides a way to overlay sections see subsection 7 10 1 Overlaying Sections With the UNION Statement on page 7 48 If either the load or run address has additional parameters such as alignment or blocking list them after the appropriate keyword Everything related to allocation after the keyword
64. With pstring values are packed into words starting with the most significant byte of the word Any unused space is padded with null bytes The assembler truncates any values that are greater than 8 bits You may have up to 100 operands but they must fit on a single source statement line If you use a label it points to the location of the first word that is initialized Note that when you use string in a struct endstruct sequence string defines a member s size it does not initialize memory For more information about Struct endstruct see Section 4 9 Assembly Time Symbol Directives on page 4 21 This example shows 8 bit values placed into words in the current section 1 000000 0041 Str Ptr String ABCD 000001 0042 000002 0043 000003 0044 2 000004 0041 string 41h 42h 43h 44h 000005 0042 000006 0043 000007 0044 3 000008 4175 pstring Austin Houston 000009 7374 00000a 696E 00000b 486F 00000c 7573 00000d 746F 00000e 6E00 4 00000f 0030 String 36 12 Assembler Directives 4 85 struct endstruct tag Declare Structure Type Syntax Description stag memo mem mam Jor size label Struct expr element expr element expr tag stag expra element exprw endstruct tag stag The struct directive assigns symbolic offsets to the elements of a data structure definition This enables you to group similar data elements together and then let the
65. application the single C54x device is booted from a 128K x 8 bit EPROM The requirement of the system is that the boot table must reside at EPROM memory address 0 Figure C 3 EPROM System for a C54x CPU C54x 128K x x8 ROMO Width 16 bits ae ROM width 8 bits EPROM system memory width 8 bits Example 3 Generating a Boot Table The on chip boot loader loads only a single block This may present a problem when you are loading C code compiled with the TMS320C54x C compiler The TMS320C54x C compiler creates several sections or blocks when it compiles C source code Some applications may require that all sections associated with the program be included in the boot to have a complete executable program In this case the individual sections must be combined into a single section for boot The hex conversion utility does not combine individual sections therefore you must use the linker to group those sections The sections that the compiler creates are divided into two categories initial ized sections sections that contain data or code and uninitialized sections sections that reserve space but contain no actual data Initialized sections created by the TMS320C54x C compiler include text cinit const and data Uninitialized sections are ignored by the hex conversion utility and are not converted Most applications require that text and cinit sections are included in the boot This allows code and information for the C
66. area for Description Both binding and memory were specified The two are mutu ally exclusive Action If you wish the code to be placed at a specific address use binding only Linker Error Messages E 3 Linker Error Messages can t align a section within GROUP not aligned Description A section in a group was specified for individual alignment The entire group is treated as one unit so the group may be aligned or bound to an address but the sections making up the group cannot be handled individually can t align within UNION section not aligned Description A section in a union was specified for individual alignment The entire union is treated as one unit so the union may be aligned or bound to an address but the sections making up the union cannot be handled individually can t allocate size page Description A section can t be allocated because no existing configured memory area is large enough to hold it Action If you are using a linker command file check that the MEMORY and SECTIONS directives allow enough room to ensure that no sections are being placed in unconfigured memory can t create map file Description Usually indicates an illegal filename Action Check spelling pathname environment variables etc The filename must conform to operating system conventions can t find input file filename Description The file filename is not in your PATH is misspelled e
67. assembler calculate the element offset This is similar to a C structure or a Pascal record A struct definition may contain a union definition and structs and unions may be nested The struct directive does not allocate memory it merely creates a symbolic template that can be used repeatedly The endstruct directives terminates the structure definition The tag directive gives structure characteristics to a abel simplifying the symbolic representation and providing the ability to define structures that con tain other structures The tag directive does not allocate memory The structure tag stag of a tag directive must have been previously defined stag expr is the structure s tag Its value is associated with the beginning of the structure If no stag is present the assembler puts the structure members in the global symbol table with the value of their absolute offset from the top of the structure Stag is optional for struct but required for tag is an optional expression indicating the beginning offset of the structure Structures default to start at 0 This parameter can only be used with a top level structure It cannot be used when defining a nested structure Declare Structure Type Struct endstruct tag memp is an optional label for a member of the structure This label is absolute and equates to the present offset from the beginning of the structure A label for a structure member cannot be declared glob
68. block RAM PG of program RAM The unused part of this RAM must be initialized to OFFFFh The xy section from demo obj which contains buffers and variables will have the default linking into block ONCHIP of data RAM since it was not explicitly linked Example 7 14 shows the linker command file for this example Example 7 15 shows the map file Linker Example Example 7 14 Linker Command File demo cmd Laan Specify Linker Options SLE BORK KK KR kCk kCk Ck KCkCKCKCK CKCK KCK KCK KCK KCK KCK KCK KCK CKCK KCK CK k KCK k ck k ck k ck k ck ck ckck ck ck sk sk A k amp x e coeff Define the program entry point o demo out Name the output file m demo map Create an output map BRK IK RR A IR KC KC kCk kCkCkCk KCk KCk KCK KCk KCKCKCk KCKCKCk KCK Ck ck K ck k ck ck ck ck ck ck ck ck ck sk ck e ke x x f Eee Specify the Input Files RES demo obj fft obj tables obj BRK KK KK EC kCkCkCk kCK kCKCkCK KCKCKCK KCK KCK
69. ck ck 0k ck ck 0k ck kk ck ck ck ck ck ck ck Ck ck ck 0k ck KK KKK ck ck ck kk ok ko Sk kv Mk Sk kv ko ko ko 31 000012 RES 2 bes 20 32 000013 0036 word 36h 33 000014 0012 word RES_2 Syntax Description Example Control Listing of Substitution Symbols SSlist ssnolist SSlist Ssnolist Two directives enable you to control substitution symbol expansion in the listing file The sslistdirective allows substitution symbol expansion inthe listing file The expanded line appears below the actual source line D The ssnolist directive suppresses substitution symbol expansion in the listing file By default all substitution symbol expansion in the listing file is inhibited Lines with the pound character denote expanded substitution symbols This example shows code that by default suppresses the listing of substitu tion symbol expansion and it shows the sslist directive assembled instructing the assembler to list substitution symbol code expansion a Mnemonic example 1 000000 bss ADDRX 1 2 000001 bss ADDRY 1 3 000002 bss ADDRA 1 4 000003 bss ADDRB 1 5 ADD2 macro ADDRA ADDRB 6 LD ADDRA A 7 ADD ADDRB A 8 STL A ADDRB 9 endm 10 11 0000008094 STL A AR4 12 000001 ADD2 ADDRX ADDRY 1 0000011000 LD ADDRX A 1 0000020001 ADD ADDRY A i 0000038001 STI A ADDRY 13 14 Sslist 15 16 000004 8094 STL A AR4 17 000005 8090 STL A ARO 18 19 000006 ADD2 ADDRX ADDRY 1 000
70. ck ck ck ck ck ck ck o ckock kk ck ko Sk kv KKK ko ko ko ko Assemble two words into section secl Sect secl word 1234h word 5678h Assemble two words into section sec2 Ck Ck ck ck Ck ck ck kk ce ck ck Ck Sk ck Ck Sk ck Ck Sk ck ck ck ck Ck ck ck ck ck Ck ck ck Ck ck ck ck ck ck kk kk KKK KKK KKK KKK KK KK Sect sec2 word 0aabbh word Occddh end C 2 Example 1 Building a Command File for Two 8 Bit EPROMS C 2 Example 1 Building A Hex Command File for Two 8 Bit EPROMs Example 1 shows how to build the hex command file you need for converting a COFF object file for the memory system shown in Figure C 1 In this system there are two external 64K x 8 bit EPROMs interfacing with a C54x target pro cessor Each of the EPROMSs contributes 8 bits of a 16 bit word for the target processor Figure C 1 A Two 8 Bit EPROM System Upper 8 bits Lower 8 bits 64K x 8 64K x 8 ROMO ROM1 Width 16 Bits ROM width ROM width 8 bits 8 bits EPROM
71. coche ce eoe ce e e e e e x kx KK 10 000001 5000 L_F field OAh 5 qal 12 l3 Initialize a 4 bit field Aue 14 EK in the same word EK 15 ck c KKK KKK KKK ck kk Ck ck kk kk ck kk xk Sk kx ko ko ko ko ko kok 16 000001 5600 x field OCh 4 T7 18 19 WE 16 bit relocatable field ASK 20 EK in the next word ER 21 cock ck ck ck ck ck Ck ck Ck ck kk ck ok kk ck ck kk ko Sk ko kv ko kv Sk ko ko kokokok 22 000002 0001 field x 23 24 ck c Ck 0k 0k ck ck ck Ck ck kk Ck ck kk kk kk xk ko kx ko ko ko ko kokok 25 Initialize a 32 bit field 26 ck c KKK KKK ck Ck ck kk Ck ck kk kk kk xk ke kx ko ko ko koc kokok 27 000003 0000 field 04321h 32 000004 4321 4 48 Initialize Field field Figure 4 6 shows how the directives in this example affect memory Figure 4 6 The field Directive Word Code 15 0 a 0 00101010111100 field OABCh 14 Fa 14 bit field b 0 00101010111100 00 field 00Ah 5 1 ioio 01010 Sa 5 bit field c 1 01010 1100 field 000Ch 4 4 bit field 010101100 0000000 field x 2 0000000000000001 e 3 0000000000000000 field 04321 32 4 0100001100100001 Assembler Directives 4 49 float xfloat Synt
72. command files are ASCII files that contain one or more of the following LJ Input filenames which specify object files archive libraries or other command files DD Linker options which can be used in the command file in the same manner that they are used on the command line The MEMORY and SECTIONS linker directives The MEMORY directive defines the target memory configuration The SECTIONS directive controls how sections are built and allocated Assignment statements which define and assign values to global sym bols To invoke the linker with a command file enter the Ink500 command and fol low it with the name of the command file Ink500 command filename The linker processes input files in the order that it encounters them If the linker recognizes a file as an object file it links it Otherwise it assumes that a file is a command file and begins reading and processing commands from it Command filenames are case sensitive regardless of the system used Linker Description 7 21 Linker Command Files Example 7 1 shows a sample linker command file called link cmd Subsection 2 4 2 Placing Sections in the Memory Map on page 2 15 con tains another example of a linker command file Example 7 1 Linker Command File a obj First input filename b obj Second input filename j o prog out Option to specify output file m prog map Option to specify map file x The sample file in
73. empty entry This allows you to skip a parameter and specify a parameter that occurs later in the list Operands that are omitted or empty assume a null value Following is an example of a C structure definition and the corresponding as sembly language statements C source struct doc char title char group int job number doc info Resulting assembly language code stag _doc 48 member _title 0 2 8 16 member _group 16 2 8 16 member job number 32 4 8 16 eos Symbolic Debugging Directives B 7 stag etag utag eos Define a Structure Syntax Description Example 1 Stag name size member definitions eos etag name size member definitions eos utag name size member definitions eos The stag directive begins a structure definition The etag directive begins an enumeration definition The utag directive begins a union definition The eos directive ends a structure enumeration or union definition fied The stag etag or utag directive should be followed by a number of member directives which define members in the structure The member directive is the only directive that can appear inside a structure enumeration or union definition The assembler does not allow nested structures enumerations or unions The C C compiler unwinds nested structures by defining them separately and then referencing them from the structure they are referenced in Follow
74. entries are used in symbolic debugging to associate addresses in the object code with the lines in the source code that generated them The line directive has two operands The line number indicates the line of the C C source that generated a portion of code Line numbers are relative to the beginning of the current function This is a required parameter The address is an expression that is the address associated with the line number This is an optional parameter if you don t specify an address the assembler will use the current SPC value Example The line directive is followed by the assembly language source statements that are generated by the indicated line of C source For example assume that the lines of C source below are line 4 and 5 in the original C source line 5 produces the assembly language source statements that are shown below C source for i 1 i lt n i p p x Resulting assembly language code 3l line 7 32 00000d 4400 LD SP 0 16 A cycle 1 33 00000e 3102 MPYA SP 2 cycle 2 34 00000f 8102 STL B SP 2 cycle 3 35 line 6 36 000010 6501 ADDM 1 SP 1 cycle 4 000011 0001 37 000012 7b8 SSBX SXM cycle 6 38 000013 495 nop 39 000014 1004 LD SP 4 A cycle 8 40 000015 0801 SUB SP 1 A cycle 9 41 000016 f842 BC L2 AGEQ cycle 10 000017 000d 42 branch occurs cycle 15 43 000018 n3 44 line 8 45 000018 1002 LD SP 2 A 46 line 9
75. fifth definition of mylab pNEOROROROECKOROR ER EKER EKER ERK EERE REAR RE KER ER KR EKER EK KR HK KEREKEKRE Sect Secto One nop mylab word 0 nop nop b mylab PR RR RRR KERR KKK KKK KEK KKK KKK KK ERK KKK ke kk k kk koc KKK ke kk KEK koe kk ke ke newblock directive allowing sixth definition of mylab g CR KORR de eo deo cede RR ERE EAE RARER RR ER dele dede RE RR RE vele ae dede e dede eoe newblock mylab word 0 nop nop b mylab 3 24 3 9 Expressions Expressions An expression is a constant a symbol or a series of constants and symbols separated by arithmetic operators The range of valid expression values is 32 768 to 32 767 Three main factors influence the order of expression evaluation Parentheses Precedence groups Left to right evaluation Expressions that are enclosed in parentheses are always evaluated first 8 4 2 4 but8 4 2 1 You cannot substitute braces or brackets for parentheses The C54x assembler uses the same order of pre cedence as the C language does as summarized in Table 3 1 This differs from the order of prece dence of other TMS320 assemblers When paren theses do not determine the order of expression evaluation the highest precedence operation is evaluated first 8 4 2 10 4 2is evaluated first When parentheses and precedence groups do not determine the order of expression evaluation the expressions are evaluated as happens in the
76. flt obj 248 Mon Nov 19 01 25 44 2001 lf you want to add new members to the library enter ar500 as function atan obj TMS320C54x Archiver Version x xx Copyright c 2001 Texas Instruments Incorporated gt symbol defined symbol name gt symbol defined symbol name gt building archive function lib Because this example doesn t specify an extension for the libname the archiver adds the files to the library called function lib If function lib didn t exist the archiver would create it The s option tells the archiver to list the global symbols that are defined in the library If you want to modify a library member you can extract it edit it and re place it In this example assume there s a library named macros lib that contains the members push asm pop asm and swap asm ar500 x macros push asm The archiver makes a copy of push asm and places it in the current directory but it doesn t remove push asm from the library Now you can edit the extracted file To replace the copy of push asm in the library with the edited copy enter ar500 r macros push asm 6 6 Chapter 7 Linker Description The TMS320C54x linker creates executable modules by combining COFF object files The concept of COFF sections is basic to linker operation Chapter 2 Introduction to Common Object File Format discusses the COFF format in detail Topic Page oll Ue OMG coco oncons coen coco MM 7 2 7 2 Linker Deve
77. forces the linker to search a library and include the member that defines the symbol The linker must encounter the u option before it links in the member that defines the symbol For example suppose a library named rts lib contains a member that defines the symbol symtab none of the object files being linked reference symtab However suppose you plan to relink the output module and you would like to include the library member that defines symtab in this link Using the u option as shown below forces the linker to search rts lib for the member that defines symtab and to link in the member lnk500 u symtab filel obj file2 obj rts lib If you do not use u this member is not included because there is no explicit reference to it in file1 0bj or file2 obj Linker Options 7 4 18 Specify a COFF Format v Option The v option specifies the format the linker will use to create the COFF object file The COFF object file is the output of the linker The format specifies how information in the object file is arranged The linker can read and write COFFO COFF1 and COFF2 formats By default the linker creates COFF2 files To create a different output format use the v option where n is 0 for COFFO or 1 for COFF1 Chapter 2 Introduction to Common Object File Format and Appendix A Common Object File Format provide further information on COFF 7 4 19 Display a Message for Output Section Information w Option The w op
78. hex conversion utility output file address field and the paddr parameter can be summarized as follows out file addrt paddr val load addr sect beg load addr x data width mem width 10 36 out file addr is the address of the output file paddr val is the value supplied with the paddr parameter inside the SECTIONS directive sec beg load addr is the section load address assigned by the linker t If paddr is not specified The value of data width divided by memory width is a correction factor for address generation The section beginning load address factor subtracted from the load address is an offset from the beginning of the section 3 The zero option When you use the zero option the utility resets the address origin to 0 for each output file Since each file starts at 0 and counts upward any address records represent offsets from the beginning of the file the address within the ROM rather than actual target addresses of the data You must use the zero option in conjunction with the image option to force the starting address in each output file to be zero If you specify the zero option without the image option the utility issues a warning and ignores the zero option Boot Loader Mode When the boot loader is used the hex conversion utility places the different COFF sections that are in the boot table into consecutive memory locations Each COFF section becomes a boot table block whose destinat
79. i 10 10 2 Controlling the Address Increment Index 0 00 cee cece ees 10 10 3 The byte Option so sas auu andaa e e bRbRER E 4e eee ee eee eee de oe 10 10 4 Dealing With Address Holes i 10 11 Description of the Object Formats i 10 11 1 ASCII Hex Object Format a Option i 10 11 2 Intel MCS 86 Object Format i Option 0 0 cece eee eee 10 11 3 Motorola Exorciser Object Format m1 m2 m3 Options 10 11 4 Texas Instruments SDSMAC Object Format t Option 10 11 5 Extended Tektronix Object Format x Option i 10 12 Hex Conversion Utility Error Messages 0 11 Mnemonic to Algebraic Translator Description seseeeeeeeeee Explains how to invoke the mnemonic to algebraic translator utility to convert a source file containing mnemonic instructions to a source file containing algebraic instructions 11 1 Translator Overview RR cette cnn RR RR e ns 11 1 1 What the Translator Does eeeseeee eens 11 1 2 What the Translator Does Not Do RII 11 2 Translator Development Flow ssssseseeee III 11 3 Invoking the Translator 0 500 0 Sri en es dn rn Xii Contents 11 4 Translation Modes sssusssssssssssssse se 11 4 1 Literal Mode Ct Option ssssssssssssssrsse eee 11 4 2 About Symbol Names in Literal Mode i 11 4 3 Expansion Mode e Option 7 11 5 How the Translator Works With Macros 000 e cece eee eee eee 11 5 4 Dire
80. in the object symbol table The first 32 characters of the name are significant Value is the value associated with the variable Any legal expression absolute or relocatable is acceptable Li Typeis the C C type of the variable Appendix A Common Object File Format contains more information about C C types Storage class is the C C storage class of the variable Appendix A Common Object File Format contains more information about C C storage classes Size is the number of bits of memory required to contain this variable Tag is the name of the type if any or structure of which this variable is a type This name must have been previously declared by a stag etag or utag directive Dims may be up to four expressions separated by commas This allows up to four dimensions to be specified for the variable The order of parameters is significant The name and value are required parameters All other parameters may be omitted or empty adjacent commas indicate an empty entry This allows you to skip a parameter and specify a parameter that occurs later in the list Operands that are omitted or empty assume a null value These lines of C source produce the sym directives shown below C source struct s int memberl member2 str int ext int array 5 10 long ptr int strcmp main argl arg2 int argl char arg2 register r1 Define a Symbol sym Resulting assembly
81. is used for macro parameters Using a macro is a three step process Step 1 Define the macro You must define macros before you can use them in your program There are two methods for defining macros Macros can be defined at the beginning of a source file or in a copy include file See Section 5 2 Defining Macros for more information Macroscan be defined in a macro library A macro library is a col lection of files in archive format created by the archiver Each member of the archive file macro library contains one macro definition corresponding to the member name You can access a macro library by using the mlib directive See Section 5 4 Macro Libraries on page 5 14 for more information Step 2 Callthe macro After defining a macro you call itby using the macro name as a mnemonic in the source program This is referred to as a macro call Step 3 Expand the macro The assembler expands your macros when the source program calls them During expansion the assembler passes arguments by variable to the macro parameters replaces the macro call statement with the macro definition and assembles the source code By default the macro expansions are printed in the listing file You can turn off expansion listing by using the mnolist directive See Section 5 8 Formatting the Output Listing on page 5 21 for more information When the assembler encounters a macro definition it places the macro name in the opcode table
82. ko ko ko 16 Start assembling into a named 17 initialized section var defs 8 19 000000 Sect var defs 20 000000 0011 word 17 18 000001 0012 21 22 23 Resume assembling into the data section 24 ck ck ck ck ck ck ck ck Sk ck ck 0k ck kk ck Ck ck ck Ck ck Ck ck ck Ck ck ck ck ck ck ck ck ck ock o ckock kk ck kk ck KK kv kx ko ko ko 25 000004 data word 13 14 27 000000 bss sym 19 Reserve space in bss 28 000006 000F word 15 16 Still in data 000007 0010 29 30 ck ck ck 0k ck ck 0k ck Sk ck ck 0k ck kk ck Ck ck ck ck ck ck ck Ck ck ck ck ck ck ck ck ck ock o ckock ck kk kk Sk Sk k Mk ko ko ko ko 3L Resume assembling into the text section 32 33 000004 text 34 000004 0005 word 5 6 000005 0006 35 000000 usym usect xy 20 Reserve space in xy 36 000006 0007 word 7 8 Still in text 4 10 Directives That Initialize Consta
83. larger than the block size the section will begin on that boundary As with alignment n must be a power of 2 For example bss load block 0x80 allocates bss so that the section either is contained in a single 128 word page or begins on a page You can use alignment or blocking alone or in conjunction with a memory area but alignment and blocking cannot be used together 7 8 8 4 Specifying input sections An input section specification identifies the sections from input files that are combined to form an output section The size of an output section is the sum of the sizes of the input sections that comprise it The linker combines input sections by concatenating them in the order in which they are specified unless alignment or blocking is specified for any of the input sections If alignment or blocking is specified for any input section the input sections within an output section are ordered as follows 1 all aligned sections from largest to smallest followed by 2 all blocked sections from largest to smallest followed by 3 all other input sections from largest to smallest Example 7 5 shows the most common type of section specification note that no input sections are listed Example 7 5 The Most Common Method of Specifying Section Contents n ECTIONS UG data MIDI The SECTIONS Directive In Example 7 5 the linker takes all the text sections from the input files and combines them i
84. linker to align the section so that individual alignments remain intact when a section is loaded into memory This example shows several types of alignment including even align 4 and a default align 1 000000 0004 byte 4 2 even 3 000002 0045 string Errorcnt 000003 0072 000004 0072 000005 006F 000006 0072 000007 0063 000008 006E 000009 0074 4 align 5 000080 6000 field 3 3 6 000080 6A00 field 5 4 7 align 2 8 000082 6000 field 373 9 align 8 10 000088 5000 field 5 4 11 align 12 000100 0004 byte 4 Assembler Directives 4 27 asg eval Syntax Description Assign Character Strings to Substitution Symbols asg character string substitution symbol eval well defined expression substitution symbol The asg directive assigns character strings to substitution symbols Substitution symbols are stored in the substitution symbol table The asg directive can be used in many of the same ways as the set directive but while set assigns a constant value which cannot be redefined to a symbol asg assigns a character string which can be redefined to a substitution symbol J The assembler assigns the character string to the substitution symbol The quotation marks are optional If there are no quotation marks the assembler reads characters up to the first comma and removes leading and trailing blanks In either case a character string is read and assigned to the substitution symbol
85. listing file It affects the current and following pages You can reset the page length with another length directive J Default length 60 lines L Minimum length 1 line J Maximum length 32 767 lines The width directive sets the page width of the output listing file It affects the next line assembled and the lines following you can reset the page width with another width directive Default width 80 characters Minimum width 80 characters Maximum width 200 characters The width refers to a full line in a listing file the line counter value SPC value and object code are counted as part of the width of a line Comments and other portions of a source statement that extend beyond the page width are trun cated in the listing The assembler does not list the width and length directives In this example the page length and width are changed BUR Page length 65 lines RP X Page width 85 characters WU length 65 width 85 xk ck ck ck ck ck kk Ck Ck ck ck kk ck ck ck kk Ck ck ck ck kk ck ck ok kk ko ck ck kk ko Sk Sk kv ko kx ko MUN Page length 55 lines ic
86. mal octal or hexadecimal fill Specifies a fill character for the memory range enter as fillor f Fills are optional The value is a 2 byte integer constant and may be decimal octal or hexadecimal The fill value will be used to fill areas of the memory range that are not allocated to a section 7 TT Note Filling Memory Ranges If you specify fill values for large memory ranges your output file will be very large because filling a memory range even with Os causes raw data to be generated for all unallocated blocks of memory in the range LLLLLLLLLL M The following example specifies a memory range with the R and W attributes and a fill constant of OFFFFh MEMORY RFILE RW o 02h 1 OFEh f OFFFFh You normally use the MEMORY directive in conjunction with the SECTIONS directive to control allocation of output sections After you use the MEMORY directive to specify the target system s memory model you can use the SECTIONS directive to allocate output sections into specific named memory ranges or into memory that has specific attributes For example you could allocate the text and data sections into the area named ROM and allocate the bss section into the area named ONCHIP Figure 7 2 illustrates the memory map shown in Example 7 3 The MEMORY Directive Figure 7 2 Memory Map Defined in Example 7 3 Data Memory Program Memo
87. not already include an extension enables assembler source debugging in the source debugger Line information is output to the COFF file for every line of source in the assembly language source file Note that you cannot use the g option on assembly code that already contains line directives i e code that was generated by the C C compiler run with g any of these options displays a listing of the available assembler options hcfilename tells the assembler to copy the spe cified file for the assembly module The file is inserted before source file statements The co pied file appears in the assembly listing files hifilename tells the assembler to include the specified file for the assembly module The file is included before source file statements The in cluded file does not appear in the assembly list ing files Assembler Description 3 5 Invoking the Assembler r S u specifies a directory where the assembler can find files named by the copy include or mlib direc tives The format of the i option is i pathname For more information see subsection 3 4 1 i As sembler Option on page 3 8 lowercase L produces a listing file specifies that assembly calls use extended ad dressing specifies that the source file contains algebraic instructions quiet suppresses the banner and all progress information r num suppresses the assembler remark identi fied by num A r
88. of code according to a true or false evaluation of an expression Two sets of directives allow you to assemble conditional blocks of code The if elseif else endif directives tell the assembler to conditionally assemble a block of code according to the evaluation of an expression The expression must be entirely specified on the same line as the directive if expression elseif expression else endif marks the beginning of a conditional block and assembles code if the if condition is true marks a block of code to be assembled if the if condition is false and elseif is true marks a block of code to be assembled if the if condition is false marks the end of a conditional block and termi nates the block The loop break endloop directives tell the assembler to repeatedly assemble a block of code according to the evaluation of an expression The expression must be entirely specified on the same line as the directive loop expression break expression endloop marks the beginning a block of code that is assembled repeatedly up to the number of times indicated by the expression The expressionis the loop count tells the assembler to continue to repeatedly assemble when the break expression is false and to go to the code immediately after endloop when the expression is true marks the end of a repeatable block The assembler supports several relational operators that are useful for
89. of expr as a floating point value pi to pi returns the smallest integer that is not less than the expression returns the hyperbolic cosine of expr as a floating point value returns the cosine of expr as a floating point value converts expr to floating point value converts exprto integer value returns the result of raising e to the expr power returns absolute value of expr as a floating point value returns the largest integer that is not greater than the expression returns the remainder after dividing expr and expr2 returns 1 if expr has an integer result returns the result of expr multiplied by 2 raised to the expr2 power returns the base 10 logarithm of expr returns the natural logarithm of expr returns the maximum of 2 expressions returns the minimum of 2 expressions Built in Functions Table 3 3 Assembler Built In Math Functions Continued Function pow expr1 expr2 round expr sgn expr sin expr sinh expr sqrt expr tan expr tanh expr trunc expr Description raises expr1 to the power expr 2 returns the result of expr rounded to the nearest integer returns the sign of expr returns the sine of expr as a floating point value returns the hyperbolic sine of expr as a floating point value returns the square root of expr as a floating point value returns the tangent of expr as a floating point value returns the hyperbolic tangent of expr as a floating point value retur
90. out map example mxp ROMS PAGE 0 ROM org 0x0000 length 0x800 romwidth 8 memwidth 8 SECTIONS secl paddr 0x0000 sec2 paddr 0x0004 Example C 6 Method Two for Avoiding Holes a Linker command file SPECIFY THE SYSTEM MEMORY MAP MEMORY PAGE 0 DARAM org 0x0080 length 0x1370 EXT org 0x1400 length 0xEB80 SECTIONS outsec secl sec2 gt EXT PAGE 0 b Hex command file a test out map example mxp ROMS PAGE 0 ROM org 0x0100 length 0x0800 romwidth 8 memwidth 8 files examp2_2 hex SECTIONS outsec paddr 0x100 Hex Conversion Utility Examples C 9 Example 3 Generating a Boot Table C 4 Example 3 Generating a Boot Table Example 3 shows how to use the linker and the hex conversion utility to build a boot load table for the C54x devices The code used in this section is shown in Example C 7 p M MM7 Note This example is for non LP C54x devices only For C54xLP devices see Section C 5 Example 4 Generating a Boot Table for LP Core Devices on page C 17 Example C 7 C Code for Example 3 int array 1 2 3 4 main Figure C 3 shows the EPROM memory system for which the output file will be generated In this
91. page directive PAGE option MEMORY directive 7 27 to 7 29 7 56 to 7 58 7 60 PAGE ROMS specification pages overlay 7 53 to PAGE syntax 7 56 to parentheses in expressions partial linking defined gofnod Fd to path See alternate directories environment vari ables pipeline conflicts precedence groups predefined names d assembler option prefixes for operands 3 13 program counters See SPC program memory Index 11 Index pstring directive ROM pw assembler option device address 10 35 to 10 38 model autoinitialization 7 74 Q defined width defined F 7 Cones Ed ono 10 13 tion 10 16 16 romname ROMS specifica 4 absolute lister option archiver option assembler option RONS a conversion utility directive 10 16 to cross reference lister option linker option Por ROMS specification 10 17 quiet run rts lib defined run address linker defined of a section to Ll run linker keyword 2 19 7 44 to runtime initialization and support archiver command assembler option 3 6 4 75 linker option S R MEMORY attribute 7 29 assembler option 3 6 RAM model linker option 7 17 7 70 to 7 71 autoinitialization 7 73 sblock directive P defined Sect directive ZEE raw data defined sect section 4 80 recursive macros ad TES ref directive 4 19 4 51 ene qs identifying TE E pis 2 21 described A 7 tojA 9 section number register symbols 3 20 f section progra
92. point Double word Structure Union Enumeration Member of an enumeration Unsigned character Unsigned short integer Bits 4 15 of the type field are arranged as six 2 bit fields that can indicate one to six derived types Table A 17 lists the possible derived types Table A 17 Derived Types Mnemonic DT NON DT PTR DT FON DT ARY Value Type No derived type Pointer Function Array An example of a symbol with several derived types would be a symbol with a type entry of 00000000110100112 This entry indicates that the symbol is an array of pointers to short integers A 7 8 Auxiliary Entries Symbol Table Structure and Content Each symbol table entry may have one or no auxiliary entry An auxiliary sym boltable entry contains the same number of bytes as a symbol table entry 18 but the format of an auxiliary entry depends on the symbol s type and storage class Table A 18 summarizes these relationships Table A 18 Auxiliary Symbol Table Entries Format Name file text data bss tagname 0S fcname arrname bb eb bf ef Name related to a structure union or enumeration Storage Class C FILE C STAT C STRTAG C UNTAG C ENTAG C EOS C EXT C STAT See note 2 C BLOCK C FON See note 2 Notes 1 Any type except T MOE 2 C AUTO C STAT C MOS C MOU C TPDEF Type Entry Derived Basic Type 1 Type DT NON T NULL DT NON T NULL DT NON T NULL
93. problems and correct per the error message text Cannot change version after 1st instruction Cannot change parsing mode after 1st instruction Can t include a file inside a loop or macro Illegal structure member Illegal structure definition contents Illegal union member Illegal union definition contents Invalid load time label Invalid structure union contents setsect only valid if absolute listing produced use a option Assembler Error Messages D 13 Assembler Error Messages setsym only valid if absolute listing produced use a option Var allowed only within macro definitions Description Action These are errors about illegally used directives Specific directives were encountered where they are not permitted because they will cause a corruption of the object file Many directives are not permitted inside of structure or union defini tions Correct the source per the error message text Include Copy file not found or opened Description Action The specified filename cannot be found Check spelling pathname environment variables etc Assembler Error Messages Copy limit has been reached Exceeded limit for macro arguments Macro nesting limit exceeded Description These errors are about general assembler limits that have been exceeded The nesting of copy include files in limited to 10 levels Macro arguments are limited to 32 parameter Macro nesting is limited to 32 levels Action Check
94. property property property name property property property 7 32 The SECTIONS Directive Each section specification beginning with name defines an output section An output section is a section in the output file After the section name is a list of properties that define the section s contents and how the section is allocated The properties may be separated by optional commas Possible properties for a section are m Load allocation which defines where in memory the section is to be loaded Syntax load allocation or allocation or gt allocation Run allocation which defines where in memory the section is to be run Syntax run allocation or run gt allocation Input sections which define the input sections that constitute the output section Syntax input sections Section type which defines flags for special section types Syntax type COPY or type DSECT or type NOLOAD For more information on section types see Section 7 13 Special Section Types DSECT COPY and NOLOAD on page 7 61 Fill value which defines the value used to fill uninitialized holes Syntax fill value or name value For more information on creating and filling holes see Section 7 15 Creating and Filling Holes on page 7 66 Example 7 4 shows a SECTIONS directive in a sample linker command file Figure 7 3 shows how these sections are allocated in memory Linker Description 7 33 The SECT
95. subsection 2 3 4 Subsections page 2 9 for more information TTAN Note Default Section Directive If you don t use any of the sections directives the assembler assembles everything into the text section LLLLLLL O OeO A O O CCCC Uninitialized Sections Uninitialized sections reserve space in processor memory they are usually allocated into RAM These sections have no actual contents in the object file they simply reserve memory A program can use this space at runtime for creating and storing variables Uninitialized data areas are built by using the bss and usect assembler directives _j The bss directive reserves space in the bss section D The usect directive reserves space in a specific uninitialized named section Each time you invoke the bss directive the assembler reserves more space in the appropriate section Each time you invoke the usect directive the assembler reserves more space in the specified named section Introduction to Common Object File Format 2 5 How the Assembler Handles Sections The syntax for these directives is bss symbol size in words blocking flag alignment flag symbol usect section name size in words blocking flag alignment flag symbol points to the first word reserved by this invocation of the bss or use
96. substitution symbol substitution symbol Table 5 4 Conditional Assembly Mnemonic and Syntax Af well defined expression Define local macro symbols Description Begin conditional assembly elseif well defined expression else endif loop well defined expression break well defined expression endloop Optional conditional assembly block Optional conditional assembly block End conditional assembly Begin repeatable block assembly Optional repeatable block assembly f End repeatable block assembly Macro Language 5 25 Macro Directives Summary Table 5 5 Producing Assembly Time Messages Mnemonic and Syntax emsg wmsg mmsg Table 5 6 Formatting the Listing Mnemonic and Syntax fclist fcnolist mlist mnolist sslist ssnolist 5 26 Description Send error message to standard output Send warning message to standard output Send warning or assembly time message to standard output Description Allow false conditional code block listing default Inhibit false conditional code block listing Allow macro listings default Inhibit macro listings Allow expanded substitution symbol listing Inhibit expanded substitution symbol listing default Chapter 6 Archiver Description The TMS320C54x archiver combines several individual files into a single archive file For example you can collect several macros into a macro library The assembler will s
97. supports the different names of the registers as they are implemented on different C54x devices 4 72 Assign Memory Mapped Register Names as Global Symbols mmregs Table 4 2 Memory Mapped Registers Continued Name SPC1 TSPC TRAD AXR TCSR TRTA AXRO ARX BKX BKXO ARR ARRO BKR AXR1 BKX1 ARR1 BKR1 BDRHR1 BDXR1 BSPC1 BSPCE1 CLKMD XPC Hexadecimal Address 0032 0032 0035 0038 0033 0034 0038 0038 0039 0039 003A 003A 003B 003C 003D 003E 003F 0040 0041 0042 0043 0058 001E Description Serial port control register 1 Serial port control register TDM receive address register ABU transmit address register TDM channel select register TDM receive transmit register ABU transmit address register ABU transmit address register ABU transmit buffer size register ABU transmit buffer size register ABU receive address register ABU receive address register ABU receive buffer size register ABU transmit address register ABU transmit buffer size register ABU receive address register ABU receive buffer size register BSP data receive register Data transmit register BSP control register BSP control extension register Clock modes register Extended memory map register Note Duplication of address values in the table supports the different names of the registers as they are implemented on different C54x devices Assembler Directives 4 73 newblock Terminate Local Symbol Block Syntax Description
98. system memory width 16 bits By default the hex conversion utility uses the linker load address as the base for generating addresses in the converted output file However for this application the code will reside at physical EPROM address 0x0010 rather than the address specified by the linker 0x1400 The circuitry of the target board handles the translation of this address space The paddr parameter allo cates a section and burns the code at EPROM address 0x0010 The paddr parameter is specified within the SECTIONS directive see Section 10 6 The SECTIONS Directive on page 10 22 for details If you use the paddr parameter to specify a load address for one section included in the con version then you must specify a paddr for each section included in the conver sion When setting the paddr parameter you must ensure that the specified addresses do not overlap the linker assigned load addresses of sections that follow In Example 1 two sections are defined sec1 and sec2 You can easily add a paddr parameter for each of these sections from within the SECTIONS direc tive However the task may become unmanageable for large applications with many sections or in cases where section sizes may change often during code development Hex Conversion Utility Examples C 3 Example 1 Building a Command File for Two 8 Bit EPROMS To work around this problem you can combine the sections at link stage creat ing a single section for conversion
99. that have the same name into an output section with that name For example suppose the files f1 0bj and f2 0bj both contain named sections called Vectors and that the SECTIONS directive does not define an output section for them The linker combines the two Vectors sections from the input files into a single output section named Vectors allocates it into memory and includes it in the output file After the linker determines the composition of all output sections it must allo cate them into configured memory The MEMORY directive specifies which portions of memory are configured if there is no MEMORY directive the linker uses the default configuration The linker s allocation algorithm attempts to minimize memory fragmentation This allows memory to be used more efficiently and increases the probability that your program will fit into memory This is the algorithm 1 Output sections for which you have supplied a specific binding address are placed in memory at that address 2 Output sections that are included in a specific named memory range or that have memory attribute restrictions are allocated Each output section is placed into the first available space within the named area considering alignment where necessary Linker Description 7 59 Default Allocation Algorithm 3 Any remaining sections are allocated in the order in which they are defined Sections notdefined ina SECTIONS directive are allocated in the order in which th
100. the default if neither a nor r is specified the linker acts as if a were specified Produce a relocatable executable object module Disable merge of symbolic debugging information Use linking conventions defined by the ROM autoin itialization model of the TMS320C54x C C com piler Use linking conventions defined by the RAM autoin itialization model of the TMS320C54x C C com piler Define a global symbol that specifies the primary entry point for the output module Set the default fill value for holes within output sec tions fill value is a 16 bit constant Keep a global symbol global overrides h Make all global symbols static Display a listing of all available linker command line options Set heap size for the dynamic memory allocation in C to sizewords and define a global symbol that speci fies the heap size The default size is 1K words Alter the library search algorithm to look in dir before looking in the default location This option must appear before the I option The directory or filename must follow operating system conventions Disable conditional linking Ignore alignment flags in input sections filename m filename o filename stack size u symbol W Linker Options Name an archive library file as linker input filename is an archive library name This option must appear af ter the i option The directory or filename must follow o
101. the command file in Example C 16 is shown in Example C 18 Example C 18 Hex Conversion Utility Output File Resulting From the Command File in Example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ex Conversion Utility Examples C 23 Appendix D Assembler Error Messages When the assembler completes its second pass it reports any errors that it encountered during the assembly It also prints these errors in the listing file if one is created An error is printed following the source line that incurred it You should attempt to correct the first e
102. the commands shown in the following table Operating System Enter Windows set A_DIR c dsys asm500 ic tools files source asm UNIX setenv A DIR dsys asm500 i tools files source asm The assembler first searches for copy1 asm and copy2 asm in the current directory because source asm is in the current directory Then the assembler searches in the directory named with the i option and finds copy1 asm Finally the assembler searches the directory named with A DIR and finds copy2 asm Note that the environment variable remains set until you reboot the system or reset the variable by entering one of these commands Operating System Enter Windows set A_DIR UNIX unsetenv A_DIR Source Statement Format 3 5 Source Statement Format 3 5 1 TMS320C54x assembly language source programs consist of source state ments that can contain assembler directives assembly language instructions macro directives and comments Source statement lines can be as long as the source file format allows Example source statements are shown below a Mnemonic instructions SYM1 set 2 Symbol SYM1 2 Begin LD SYM1 AR1 Load AR1 with 2 word 016h Initialize word 016h b Algebraic instructions SYM1 set 2 Symbol SYM1 2 Begin AR1 SYM1 Load AR1 with 2 data byte 016h Initialize word 016h Source Statement Syntax A source statement can contain four ordered fields The general syntax for Source stateme
103. the source to determine how limits have been exceeded Pass conflict Description This is an internal assembler error If it occurs repeatealy the assembler may be corrupt or confused Action Assemble a smaller file If a smaller file does not assemble reinstall the assembler Pipeline conflict detected Description This error reports a pipeline conflict Action Check the source to determine what caused the problem and correct the source Illegal use of EXPR notation Illegal use of SP notation Description This error reports a notation problem Action Check the source to determine what caused the problem and correct the source Assembler Error Messages D 15 Assembler Error Messages Ambiguous assignment Invalid page number specified ignored Macro parameter conflict No operands expected Operands ignored Specified alignment is outside accessible memory ignored Trailing operand does not exist Trailing operands ignored Unrecognized operand ignored ARn addressing is for write only Description These are warnings about operands The assembler encoun tered operands that it did not expect Action Check the source to determine what caused the problem and whether you need to correct the source Assembler Error Messages Field value truncated to value Field width truncated to size in bits Immediate value out of range Legal shift values are Maximum alignment is to 32K boundary alignment igno
104. to approximate the function of UNION but this is cumbersome LLLLLLLLLLLLL L 3 7 10 2 Grouping Output Sections Together The SECTIONS directive has a GROUP option that forces several output sections to be allocated contiguously For example assume that a section named ferm rec contains a termination record for a table in the data section You can force the linker to allocate data and term rec together Example 7 9 Allocate Sections Together SECTIONS text Normal output section EI bss Normal output section Ae GROUP 1000h Specify a group of sections data First section in the group term_rec Allocated immediately after data You can use binding alignment or named memory to allocate a GROUP in the same manner as a single output section In the preceding example the GROUP is bound to word address 1000h This means that data is allocated at word 1000h and term_rec follows it in memory The alignment and block attributes of a GROUP are the maximum alignment and block attributes of any of its members An allocator for a GROUP is subject to the consistency checking rules listed in Section 7 10 4 Using UNION and GROUP Statements 7 10 3 Nesting UNIONs and GROUPs The linker allows arbitrary nesting of GROUP and UNION statements with the SECTIONS directive By nesting GROUP and UNION statements you can expres
105. zero filled Index of next entry past this block Unused zero filled A 7 8 9 Names Related to Structures Unions and Enumerations Table A 27 illustrates the format of auxiliary table entries for the names of structures unions and enumerations Table A 27 Structure Union and Enumeration Names Format for Auxiliary Table Entries Byte Number 0 3 4 5 6 7 8 17 16 17 Type Long integer Unsigned short integer Description Tag index Unused zero filled Size of the structure union or enu meration Unused zero filled Unused zero filled Common Object File Format A 27 Appendix B Symbolic Debugging Directives The TMS320C54x assembler supports several directives that the TMS320C54x C C compiler uses for symbolic debugging The sym directive defines a global variable a local variable or a function Several parameters allow you to associate various debugging information with the symbol or function The stag etag and utag directives define structures enumerations and unions respectively The member directive specifies a member of a structure enumeration or union The eos directive ends a structure enu meration or union definition The func and endfunc directives specify the beginning and ending lines of a C C function The block and endblock directives specify the bounds of C C blocks Lj The file directive defines a symbol in the symbol table that identif
106. 0 PROG origin 001400h length 01000h PAGE 1 DATA origin 0080h length 01000h SECTIONS text gt PROG PAGE 0 cinit gt PROG PAGE 0 data gt DATA PAGE 1 Dbss gt DATA PAGE 1 Const gt DATA PAGE 1 Sysmem gt DATA PAGE 1 Stack gt DATA PAGE 1 Example C 15 shows the map file generated when the linker is executed with the command file in Example C 14 Linking with this command file creates a COFF file you use as input to the hex conversion utility to build the desired boot table Example C 15 Section Allocation Portion of Map File Resulting From the Command File in Example C 14 PUT FILE NAME lt c54xlp out gt TRY POINT SYMBOL c int00 address 00001404 Gl za EMORY CONFIGURATION name origin length used attributes fill PAGE 0 PROG 00001400 000001000 0000007a RWIX PAGE 1 DATA 00000080 000001000 00000426 RWIX Hex Conversion Utility Examples C 19 Example 4 Generating a Boot Table for LP Core Devices Example C 15 Section Allocation Portion of Map File Resulting From the Command File in Example C 14 Continued SECTION ALLOCATION MAP output attributes section page origin length input sections text 0 00001400 0000006d 00001400 00000004 c54xlp obj text 00001404 0000002b rts lib boot obj text
107. 0 00000a 0033 000005 003A 6 7 00000c 8 9 000018 1 000018 003A 000019 0070 00001a 0031 000015 003A 00001c 003A 00001d 0070 00001e 0032 00001f 003A 000020 003A 000021 0070 000022 0033 000023 003A STR 3 smacro Pl P2 P3 JSLring ipli ripas Sips endm BUR OS Must VAS Cam Strazng ipli y Spor psi mnolist STR doas IN am mlist STR S ag SIN Hag Strzng ipli pO ips Syntax Description mmregs Assign Memory Mapped Register Names as Global Symbols mmregs The mmregs directive defines global symbolic names for the C54x registers and places them in the global symbol table It is equivalentto executing AL set 8 AH set 9 etc The symbols are local and absolute Using the mmregs directive makes it unnecessary to define these symbols Table 4 2 Memory Mapped Registers Name IMR IFR STO ST1 AL AH AG BL BH BG TRN BK BRC RSA REA PMST DRRO BDRR Note Hexadecimal Address 0000 0001 2 5 0006 0007 0008 0009 000A 000B 000C 000D 000E 000F 0019 001A 001B 001C 001D 0020 0020 Description Interrupt mask register Interrupt flag register Reserved Status 0 register Status 1 register A accumulator low A 15 0 A accumulator high A 31 16 A accumulator guard A 39 32 B accumulator low B 15 0 B accumulator high B 31 16 B accumulator guard B 39 32 Temporary register Transition register Circular size register
108. 0 45 DSECT section producing in macros etag symbolic debugging directive dummy section 7 61 y Ee etext linker symbol eval directive g listing control use in macros evaluation of expressions 3 25 e absolute lister option even directive hex conversion utility option 10 32 executable module defined linker option 7 11 executable output edata linker symbol 7 65 expression else directive 4 56 absolute and relocatable use in macros 5 15 arithmetic operators in elseif directive 4 20 4 56 conditional 3 27 ssinmacr s 5 15 conditional operators in ae defined emsg directive 4 24 4 42 5 19 7 listing control 4 17 4 41 xd illegal emulator defined linker end linker symbol overflow end directive 4 23 1 44 precedence of operators 3 25 ae relocatable symbols in 3 28 endblock symbolic debugging underflow endfunc symbolic debugging directive B 5 well defined 13 27 endif directive 4 56 extended addressing loading values into 3 32 use in macros 5 15 external symbols 2 21 endloop directive 4 20 defined use in macros 5 15 relocatable endm directive 5 3 endstruct directive 4 21 n endunion directive 4 22 entry point f linker option 7 11 defined F 3 far mode directive value assigned fclist directive 4 17 4 46 enumeration definitions listing control 4 17 4 41 environment variables use in macros fcnolist directive 3 listing control
109. 00 05 2001 Copyright c 2001 Texas Instruments Incorporated modulel abs PAGE 1 22 002000 text 23 Copy modulel asm A 1 002000 text A 2 008000 bss array 100 A 3 008064 bss dflag 2 A 4 Copy globals def B 1 global dflag B 2 global array B 3 global offset A 5 002000 F020 ld offset A 002001 8066 A 6 002002 1064 ld dflag A No Errors No Warnings Figure 8 3 module2 Ist TMS320C54x COFF Assembler Version x xx Wed Oct 16 12 00 17 2001 Copyright c 2001 Texas Instruments Incorporated module2 abs PAGE 1 22 002003 text 23 CODY module2 asm A 1 008066 bss offset 2 A 2 Copy globals def B 1 global dflag B 2 global array B 3 global offset A 3 002003 F020 id offset A 002004 8066 A 4 002005 F020 ld farray A 002006 8000 No Errors No Warnings Absolute Lister Description 8 9 Chapter 9 Cross Reference Lister Description The cross reference lister is a debugging tool This utility accepts linked object files as input and produces a cross reference listing as output This listing shows symbols their definitions and their references in the linked source files Topic Page 9 1 Producing a Cross Reference Listing aun aunaenannn 6 2 9 2 Invoking the Cross Reference Lister na nnanaannann 8 3 9 3 Cross Reference Listing Example 0 00 9 4 9 1 Producing a Cross Reference Listing 9 1 Producing a Cross Reference Listing Figure 9 1 C
110. 00 INIT 6 000000 F000 ADD 56h A 000001 0056 7 000002 0000 word X 8 i 9 7 10 11 end 4 52 Identify Global Symbols global def ref file4 Ist I Global symbols defined in this file 2 def X Y Z 3 Global symbol defined in file3 1st 4 ref INIT S 0001 X Set 1 6 0002 Y Set 2 7 0003 Z Set 3 8 000000 0000 word INIT 9 10 11 12 end Assembler Directives 4 53 half uhalf short ushort nitialize 16 bit Integer Syntax Description half value valuen uhalf value valuen Short value valuej ushort value valuen The half uhalf short and ushort directives place one or more values into consecutive 16 bit fields in the current section A value can be Anexpression that the assembler evaluates and treats as an 16 bit signed or unsigned number D A character string enclosed in double quotes Each character in a string represents a separate value The valuescan be either absolute or relocatable expressions If an expression is relocatable the assembler generates a relocation entry that refers to the appropriate symbol the linker can then correctly patch relocate the refer ence This allows you to initialize memory with pointers to variables or labels The assembler truncates values greater than 16 bits You can use as many values as fiton a single line but the total line length cannot exceed 200 charac ters If you use a label i
111. 0000 100f add LD OFh A 20 000001 010 aloop SUB 1 A 000002 0001 21 000003 f842 BC aloop AGEQ 000004 0001 22 ck ck Ck ck ck 0k ck Sk 0k ck Ck ck ck Ck ck kk ck Ck ck ck ck ck kc ck ck ck ck ck ck ck ock ck ck ck kk ck Sk Sk Mk ko ko ko ko 23 ax Another initialized table into data ay 24 25 000004 data 26 000004 00aa ivals word OAAh OBBh OCCh 000005 00bb 000006 00cc 27 ck ck Ck ck ck 0k ck 0k ck Ck ck ck Ck ck 0k ck ck ck ck ck kc kc ck ck ck ck ck ck ck ock ck ck ck kk ck Sk ke Mk ko ko ko ko 28 Define another section for more variables 29 30 000000 vara usect newvars 1 31 000001 inbuf usect newvars 7 el ck ck Ck ck ck 0k ck kc ck Ck ck ck Ck KKK ck Ck ck ck ck ck kc ck ck ck ck ck ck ck ock ck ck ck kk ck KK KKK ko ko 33 mE Assemble more code into text xum 34 35 000005 text 36 000005 110a mpy LD OAh B 37 000006 166 mloop MPY 0Ah B 000007 000a 38
112. 000008 868 BC mloop BNOV 000009 0006 39 40 xx Define a named section for int vectors 41 ck ck Ck ck ck 0k ck 0k ck Ck ck ck Ck KKK ck Ck ck ck ck ck ck ck ck ck ck ck ck ck ckock ck ck ck kk ck Sk ke Mk ko ko ko ko 42 000000 Sect vectors 43 000000 0011 word 011h 033h 44 000001 0033 wv AV FT SS Field1 Field2 Field3 Field 4 Introduction to Common Object File Format 2 11 How the Assembler Handles Sections As Figure 2 2 shows the file in Example 2 1 creates five sections text contains ten 16 bit words of object code data contains seven words of object code vectors is a named section created with the sect directive it contains two words of initialized data bss reserves 10 words in memory newvars is anamed section created with the usect directive itreserves eight words in memory The second column shows the object code that is assembled into these sections the first column shows the line numbers of the source statements that generated the object code Figure 2 2 Object Code Generated by the File in Example 2 1 2 12 Line Numbers Object Code Section 19 text 20 20 21 21 36 37 37 38 38 data 14 26 26 26 43 0011 vectors 44 0033 No data bss 10 words 10 reserved No dat
113. 0000142f 0000003e exit obj text cinit 0 0000146d 0000000d 0000146d 00000006 c54xlp obj cinit 00001473 00000006 rts lib exit obj cinit 00001479 00000001 HOLE fill 0000 data 1 00000080 00000000 UNINITIALIZED 00000080 00000000 c54xlp obj data 00000080 00000000 rts lib exit obj data 00000080 00000000 boot obj data bss ah 00000080 00000026 UNINITIALIZED 00000080 00000004 c54xlp obj bss 00000084 00000000 rts lib s boot obj bss 00000084 00000022 exit obj bss const 1 00000080 00000000 UNINITIALIZED sysmem 1 00000080 00000000 UNINITIALIZED stack 1 000000a6 00000400 UNINITIALIZED 000000a6 00000000 rts lib boot obj stack GLOBAL SYMBOLS address name address name 00000080 bss 00000001 lflags 00000080 data 00000080 array 00001400 text 00000080 data 0000144b CSSEXIT 00000080 bss 00000400 STACK SIZE 00000080 edata 00000085 cleanup ptr 00000085 cleanup ptr 00000001 lflags 000000a6 end 00001467 _abort 00000400 STACK SIZE 00000080 array 00001400 text 0000144e _atexit 00001400 main 00001404 c int00 00001404 c int00 0000142f exit 0000142f exit 00001400 main 0000144b CSSEXIT 0000146d cinit 0000144e _atexit 00000080 edata 00001467 _abort 000000a6 end 0000146d etext 0000146d etext 0000146d cinit ffffffff pinit ffffffff pinit 18 symbols C 20 Example 4 Generating a Boot Table for LP Core Devices The hex conversion utility has options that describe the requi
114. 000h length 01000h P MEM3 origin 06000h length 01000h P MEMA origin 08000n length 01000h SECTIONS text gt P_MEM1 P MEM2 P_MEM4 The operator is used to specify the multiple memory ranges The text out put section will be allocated as a whole into the first memory range in which it fits The memory ranges are accessed in the order specified In this example the linker will first try to allocate the section in P_MEM1 If that attempt fails the linker will try to place the section into P_MEM2 and so on If the output section is not successfully allocated in any of the named memory ranges the linker issues an error message With this type of SECTIONS directive specification the linker can seamlessly handle an output section that grows beyond the available space of the memory range in which it is originally allocated Instead of modifying the linker com mand file you can let the linker move the section into one of the other areas The SECTIONS Directive 7 8 3 6 Automatic Splitting of Output Sections Among Non Contiguous Memory Ranges The linker can split output sections among multiple memory ranges to achieve an efficient allocation Use the gt gt operator to indicate that an output section can be split if necessary into the specified memory ranges For example MEMORY P MEM1 origin 02000h length 01000n P MEM2 origin 04000h length 01000h P MEM3 origin 0600
115. 0061000 LD ADDRA A LD ADDRX A 1 0000070001 ADD ADDRB A ADD ADDRY A 1 0000088001 STL A ADDRB STL A ADDRY Assembler Directives 4 83 sslist ssnolist 4 84 Control Listing of Substitute Symbols b Algebraic example ji dE DO SE BO 3B LO 13 14 355 16 17 18 19 000000 000001 000002 000003 ADD2 0000008094 000001 0000011000 0000020001 0000038001 000004 8094 000005 8090 000006 0000061000 0000070001 0000088001 bss ADDRX 1 bss ADDRY 1 bss ADDRA 1 bss ADDRB 1 nacro ADDRA ADDRB A ADDRA A A ADDRB ADDRB A endm AR4 A ADD2 ADDRX ADDRY A ADDRX A A ADDRY ADDRY A Sslist AR4 A ARO A ADD2 ADDRX ADDRY A QADDRA A QADDRX A A ADDRB A A ADDRY ADDRB A ADDRY A Syntax Description Example Initialize Text string pstring String string string pstring string stringa The string and pstring directives place 8 bit characters from a character string into the current section With the string directive each 8 bit character has its own 16 bit word but with the pstring directive the data is packed so that each word contains two 8 bit bytes Each string is either _j Anexpression that the assembler evaluates and treats as a 16 bit signed number or A character string enclosed in double quotes Each character in a string represents a separate byte
116. 014 000015 000016 300 ALS LOCI A TEMP 48h A A LOC1 4 CCCh 000F F485 F000 000F 8000 START TEMP Space oSet bss ABS ADD STL end 300 15 LOC1 48h A TEMP A A LOC1 Syntax Description Specify Far Calls and Branches far mode far mode The far mode directive tells the assembler that the assembly file uses extended addressing calls and branches extend beyond the normal 16 bit range This directive has the same effect as using the mf assembler option If your program uses extended addressing and your assembly code was not generated by the C compiler you should add the c mode directive to your assembly files Assembler Directives 4 45 fclist fcnolist Control the Listing of False Conditional Blocks Syntax fclist fcnolist Description Two directives enable you to control the listing of false conditional blocks The fclist directive allows the listing of false conditional blocks conditional blocks that do not produce code The fcnolist directive suppresses the listing of false conditional blocks until a fclist directive is encountered With fcnolist only code in conditional blocks that are actually assembled appears in the listing The if elseif else and endif directives do not appear By default all conditional blocks are listed the assembler acts as if the fclist directive had been used Example This example shows the assembly langu
117. 0h length 01000h P MEMA origin 08000h length 01000h SECTIONS text text gt gt P MEM1 P MEM2 P MEM3 P MEM4 In this example the gt gt operator indicates that the text output section can be split among any of the listed memory areas If the text section grows beyond the available memory in P MEM 1 it is split on an input section boundary and the remainder of the output section is allocated to P MEM2 P MEMS P MEM4 The operator is used to specify the list of multiple memory ranges You can also use the gt gt operator to indicate that an output section can be split within a single memory range This functionality is useful when several output sections must be allocated into the same memory range but the restrictions of one output section cause the memory range to be partitioned Consider the following example MEMORY RAM origin 01000h length 08000n SECTIONS Sspecial fl obj text 04000h text text gt gt RAM The special output section is allocated near the middle of the RAM memory range This leaves two unused areas in RAM from 01000h to 04000h and from the end of f1 obj text to 08000h The specification for the text section allows the linker to split the text section around the special section and use the available space in RAM on either side of special Linker Description 7 41 The SECTIONS Directive The operator c
118. 12 Figure 7 6 Overlay Pages Defined by Example 7 11 and Example 7 12 7 54 Program Memory Data Memory Data Memory Page 0 Page 1 Page2 OVR MEM OVR MEM Run address f f for f1 f2 f3 f1 obj text f3 obj text i4 f2 obj text f4 0bj text 2C00h PROG 2C00h pata Overlay Pages 7 11 2 Using Overlay Pages With the SECTIONS Directive Assume that you are using the MEMORY directive as shown in Example 7 11 Further assume that your code consists of besides the usual sections four modules of code that you want to load in data memory space but that you intend to run in the on chip RAM in program memory space Example 7 12 shows how to use the SECTIONS directive overlays accordingly Example 7 12 SECTIONS Directive Definition for Overlays in Figure 7 6 SECTIONS UNION run ONCHIP S1 load OVR MEM PAGE 1 sl_load 0A00h sl_start fl obj text f2 0bj text sl length sl_start 2 load OVR MEM PAGE 2 S2 load 0A00h s2 start f3 0bj text f4 0bj text s2 length s2 start text load PROG PAGE 0 data load PROG PAGE 0 bss load DATA PAGE 1 JN The four modules of code are f1 f2 f3 and f4 The modules f1 and f2 are combined into output section S1 and f3 and f4 are combined into output section S2 The PAGE specifications for S1 and S2 tell the linker to link these sections into the corr
119. 2 you ee adore ka Re n e RR REEERE ORE n RUE rn 7 5 The Most Common Method of Specifying Section Contents i 7 6 Copying a Section From ROM to RAM ssssssssessese n eens 7 7 The UNION Statement i 7 8 Separate Load Addresses for UNION Sections i 7 9 Allocate Sections Together 0 7 10 Nesting GROUP and UNION statements i 7 11 Memory Directive With Overlay Pages ssssssssssse eh xviii 00 O CI m Oo LLL oR Ww OOO OOO QUO QOO O O O O O C LLL oN O Contents SECTIONS Directive Definition for Overlays in Figure 7 6 se Default Allocation for TMS320C54x Devices i Linker Command File demo cmd 0 ccc cee ee RR n Output Map File demo map sa si a nEn NEEE EERE nee tenes A ROMS Directive Example i Map File Output From Example 10 1 Showing Memory Ranges Treatment of Symbol Names in Literal Mode i Expansion MOde sae i ee a Directives in Macros a a a ee i a a aaae ES Macro Local Variables 2 c ces isse pede RR edu cu E Ra e ed dona Assembly Code for Hex Conversion Utility Examples i A Linker Command File for Two 8 Bit EPROMS i A Hex Command File for Two 8 Bit EPROMS eee Map File Resulting From Hex Command File in Example C 3 on page C 5 Method One for Avoiding Holes i Method Two for Avoiding Holes sssssessseeese eens C Code for Example 3 a sa enn Linker Command File to Form a Single Boot Section i Sectio
120. 4 17 4 41 C54X A DIR use in macros C54X C DIR field defined eos symbolic debugging directive field directive equ directive compatibility with C1x C2x C2xx C5x 7 13 7 15 Index 6 file copy identification B 4 include file header defined F 3 structure A 5 file symbolic debugging directive filenames as character strings copy include files 8 8 extensions changing defaults list file macros in macro libraries object code files ROMS specification 10 18 fill MEMORY specification ROMS specification 10 17 value default Eh explicit initialization 69 setting 7 41 fill hex conversion utility option 10 27 fill value See hole float directive compatibility with C1x C2x C2xx C5x floating point constants 4 50 func symbolic debugging directive B 5 function definitions functions built in assembler option 8 5 linker option global defined F 3 symbols 7 12 global directive identifying external symbols GROUP defined linker directive Index h assembler option linker option half directive limiting listing with option directive 4 17 hc assembler option heap linker option sysmem section described help assembler option linker option hex conversion utilit command file ca 10 8 controlling ROM device address 10 35 to 10 38 data width defined described development flow 10 2 error messages examples avoiding holes with multiple sections E d to
121. 7 00BD AABB 15AA 0045 00BD 00B0 0005 AABB CCDD 0000 0259 15AA 0078 0045 0078 0074 0065 006E 0064 0065 0064 0020 0052 0065 0067 0069 0073 0074 0065 0072 0073 Limit the listing of byte word long and string directives to 1 line each B W L T C OBOh OAABBCCDDh 5546 78h Extended Registers option byte long word string 5 536 4 At Reset the listing options option R byte C OBOh 5 long OAABBCCDDh 536 A word 5546 78h I String Extended Registers Assembler Directives option This example shows how to limit the listings of the byte word long and 4 77 page Eject Page in Listing Syntax Description Example page The page directive
122. 7 8 ssss 7 6 Overlay Pages Defined by Example 7 11 and Example 7 12 LL 7 7 RAM Model of Autoinitialization et 7 8 ROM Model of Autoinitialization ee 8 1 Absolute Lister Development Flow sssssssssee III 8 2 imodulet ISt s 4 ooLepeo cepere Dey uenesue ruere SS HIR HEUS E UU S SR Fut E 8 3 module2 Ist iui a daos dra eeu sd aee i Rd oe a ond Do RE Ce Bad 9 1 Cross Reference Lister Development Flow i 10 1 Hex Conversion Utility Development Flow i 10 2 Hex Conversion Utility Process Flow se 10 3 Data and Memory Widths et 10 4 Data Memory and ROM Widths i 10 5 C54x Memory Configuration Example i 10 6 Varying the Word Order 0 00 c ccc cc cee nent re 10 7 The infile out File From Example 10 1 Partitioned Into Four Output Files 10 8 Sample Command File for Booting From a C54x EPROM sssseus 10 9 Hex Command File for Avoiding a Hole at the Beginning of a Section 10 10 ASCII Hex Object Format i 10 11 Intel Hex Object Format i xiv Contents 10 12 Motorola S Format en 10 13 Tl Tagged Object Format isssssssssssssesssee e n 10 14 Extended Tektronix Object Format ot 11 1 Translator Development Flow 0 00 c cece eee In 11 2 Literal Mode Process 0 11 3 Expansion Mode Process i cece cece sens 11 4 Defining Labels 0 11 5 Rewritten Source Code 0c c cc tne n A 1 COFF File Structure ae a Ai A 2
123. 8h Setsect text 02003h Setsect data 08000n Setsect bss 08066h list text Copy module2 asm Absolute Lister Description 8 7 Absolute Lister Example Step 4 These files contain the following information that the assembler needs when you invoke it in step 4 They contain setsym directives which equate values to global symbols Both files contain global equates for the symbol dflag The symbol dflag was defined in the file globals def which was included in module1 asm and module2 asm DD They contain setsect directives which define the absolute addresses for sections J They contain copy directives which tell the assembler which assembly language source file to include The setsym and setsect directives are not useful in normal assembly they are useful only for creating absolute listings Finally assemble the abs files created by the absolute lister remember that you must use the a option when you invoke the assembler asm500 a modulel abs asm500 a module2 abs This creates two listing files called module1 Ist and module2 Ist no object code is produced These listing files are similar to normal listing files however the addresses shown are absolute addresses The absolute listing files created are module1 Ist see Figure 8 2 and module2 Ist see Figure 8 3 Absolute Lister Example Figure 8 2 module1 st TMS320C54x COFF Assembler Version x xx Wed Oct 16 12
124. 9 1 Operators ccrte en rera e Ue beer p Ee Re 3 9 2 Expression Overflow and Underflow i 3 9 8 Well Defined Expressions i 3 9 4 Conditional Expressions i 3 9 5 Relocatable Symbols and Legal Expressions i 810 Bulin FUnctornis iius odes eir RESTE RREC TQ E Qr ERE Eres EUR S Ere 3 11 Loading Values into Extended Program Memory pp 8 12 Source Listings sarearen iuam pea Reque E Que en NIN RE E 3 13 Cross Reference Listings es 4 Assembler Directives I Imm nnn Describes the directives according to function and presents the directives in alphabetical order 4 1 Directives Summary sad mia rd a hme 4 2 Compatibility With the TMS320C1x C2x C2xx C5x Assembler Directives 4 3 Directives That Define Sections 0 4 4 Directives That Initialize Constants 0 4 5 Directives That Align the Section Program Counter cece eee eee 4 6 Directives That Format the Output Listing i 4 7 Directives That Reference Other Files i viii Contents 4 8 Conditional Assembly Directives es 4 9 Assembly Time Symbol Directives 4 10 Miscellaneous Directives i 4 11 Directives Reference 0 Macro Language Describes macro directives substitution symbols used as macro parameters and how to create macros ST UsimgMacrios osse RD REX MEEWERER X RRPR E RE RAE RE RA ded eee ee eee 5 2 Defining Macros sm dedere rutru ar eee d a Roe ARR a dO Rund ar ied 5 3 Macro Parameters Substitution Symbols i 5 3 4 Directives That Define Substitution S
125. AGI tag REAL REC I3 0004 CPLX LEN endstruct 14 15 COMPLEX tag CPLX REC 16 17 000002 bss COMPLEX CPLX LEN 18 19 000001 0002 ADD COMPLEX REALI A 20 000002 8002 STL A COMPLEX REALI 21 22 000003 0104 ADD COMPLEX IMAGI B Example 3 1 struct 2 3 0000 X int 4 0001 Y int 5 0002 Z int 6 0003 endstruct Example 4 T BIT_REC struct 2 0000 STREAM string 64 3 0040 BIT field 7 4 0040 BIT9 field 9 5 0041 BIT10 field 10 6 0042 X INT int 7 0043 BIT LEN endstruct 8 9 BITS tag BIT REC 10 000000 0040 ADD BITS BIT7 A 4 88 allt 12 13 000001 030 000002 007f 000000 AND 007Fh bss BITS QA BIT REC stag memberl 0 member2 1 real len 2 A access structure element allocate mem rec stag memberl 0 cplx_len 4 assign structure attrib access structure allocate space no stag puts mems into global symbol table create 3 dim templates stag bitsl 64 bits2 64 bits3 65 X int 66 length 67 move into acc mask off garbage bits Define Tab Size tab Syntax tab size Description The tab directive defines the tab size Tabs encountered in the source input are translated to size spaces in the listing The default tab size is eight spaces Example Each of the following lines consists of a single tab character followed by an NOP instruction Source file
126. CKCK KCKCKCKCKCK KCKCKCk KCK k ck k ck k ck ck ck ck ck ck ck ks ke x k amp x f JERR Specify the Memory Configurations ASR f MEMORY Ij PAGE 0 RAM PG origin 00080h length 06F80h ROM origin 0C000h length 03F80h PAGI EH 1 ONCHIP origin 00080h length 0F7Fh EXT origin 01000h length 0EFFFh KK IKK IK AR A RA kCkCkCk KCKCKCk KCkCkCk KCKCkCk KCkCkCk KCk kc k k ck ck ck ck ckck ck ck ck A A k e ke I I Specify the Output Sections PEAY BRK KK RK kCk Ck KCkCK kCK KCK CkCK KCK KCK KCK CKCK A CKCK AR Ck ck k ck k OR OR eR Ke f SECTIONS text load ROM page 0 link text into ROM var defs load ONCHIP page 1 defs in RAM data fill 07A1Ch load ONCHIP page 1 tables obj data data input fft obj data data input 100h create hole fill with 07A1Ch and link with ONCHIP bss load RAM PG page 0 fill 0FFFFh Remaining bss fill and link BORK RK KK RK Ck K kCK KCK kCK KCK KCK CKCK KCKCKCK CKCKCKCK KCK KCK CKCK KCK Ck k k k k ck RR RK f End of Command File KK IK RK A RA ECC KCk kCkCkCk KCKCKCk KCk KCk KCK KCk KCKCKCk KCKCk ck k ck k ck k ck ck ck ck ckck ck ko sk
127. COFF Object File sie BERE Tepped prever rhe En DEL e e pedis A 3 Section Header Pointers for the text Section i A 4 Line Number Blocks 00 000 c cece tenet nena A 5 Line Number Entries ami A 6 Symbol Table Contents sss rod er hn A 7 Symbols for Blocks eiriaa ccc een eee eee A 8 Symbols for Functions 2 00 0 c cece ehh A 9 Sting lable s centi ERU RE RR Eres ea Rede pea Reese ERN n ERAN C 1 A Two 8 Bit EPROM System 4 C 2 Data From Output File 0 C 3 EPROM System fora C54x ss C 4 EPROM System for a C54xLP ss a i ei tenet eens Contents XV Tables 3 1 Operators Used in Expressions Precedence i 3 2 Expressions With Absolute and Relocatable Symbols 3 3 Assembler Built In Math Functions ssssssssssess ee 3 4 Symbol At 4 1 Assembler Directives Summary 0 4 2 Memory Mapped Registers pp 5 1 Functions and Return Values 00 cece nn 5 2 Creating Macros sa sd a a eee hc 5 3 Manipulating Substitution Symbols i 5 4 Conditional Assembly 0 0 a cece a a eee eens 5 5 Producing Assembly Time Messages ssssssseesee eh 5 6 Formatting the Listing ta si 7 1 Operators Used in Expressions Precedence pp 9 1 Symbol Attributes ses ds nd ne hs 10 1 Hex Conversion Utility Options 0 10 2 BootLoader Options ns i sser nn 10 3 Options for Specifying Hex Conversion Formats eee ellen A 1 File Header Contents 00 cece cece tenet eee eee eens A 2 File H
128. Command File 10 3 1 Examples of Command Files 10 8 Assume that a command file named firmware cmd contains these lines firmware out input file t TI Tagged xy 0 firm lsb output file 1 LSBs of ROM 0 firm msb output file 2 MSBs of ROM You can invoke the hex conversion utility by entering hex500 firmware cmd This example converts a file called appl out into four hex files in Intel format Each output file is one byte wide and 16K bytes long The text section is converted to boot loader format appl out input file i Intel format map appl mxp map file f ROMS ROW1 origin 01000h len 04000h romwidth 8 files appl u0 appl ul ROW2 origin 05000h len 04000h romwidth 8 files appl u2 appl u3 wn ECTIONS text BOOT data cinit sectl vectors const Understanding Memory Widths 10 4 Understanding Memory Widths The hex conversion utility makes your memory architecture more flexible by allowing you to specify memory and ROM widths In order to use the hex conversion utility you must understand how the utility treats word widths Four widths are important in the conversion process target width data width memory width and ROM width The terms target word data word memory word and ROM word refer to a word of such a width Figure 10 2 illustrates the three separate and distinct phases of the hex conversion utility s process flow Figure 10 2 Hex C
129. EF of y The def definition of x says that itis an external symbol defined in this module and that other modules can reference x The ref definition of y says that it is an undefined symbol that is defined in another module The assembler places both x and y in the object file s symbol table When the file is linked with other object files the entry for x defines unresolved references to x from other files The entry for y causes the linker to look through the symbol tables of other files for y s definition The linker must match all references with corresponding definitions If the linker cannot find a symbol s definition it prints an error message about the unresolved reference This type of error prevents the linker from creating an executable object module Introduction to Common Object File Format 2 21 Symbols in a COFF File 2 8 2 The Symbol Table The assembler always generates an entry in the symbol table when it encoun ters an external symbol both definitions and references The assembler also creates special symbols that point to the beginning of each section the linker uses these symbols to resolve the address of and references symbols that are defined in the section The assembler does not usually create symbol table entries for any symbols other than those described above because the linker does not use them For example labels are not included in the symbol table unless they are declared with global For sy
130. Entries es 3 1 n Local Labels cererea EE RR xx EEXA E RER de AE TAa adu EAD Persona EEES 3 2 name Local Labels oe 3 3 Well Defined Expressions lusussssssssses IIR e eens 3 4 Assembler Listing ss 3 5 Sample Cross Reference Listing pp 4 1 Sections Directives eeo 0 ani Ann KaRa AESA RD EANAN RA 5 1 Macro Definition Call and Expansion i 5 2 Calling a Macro With Varying Numbers of Arguments i 5 3 The zasg Directive oa eredi ERROR REEPRURMR S ERROR IRURE IR earns 5 4 The lt e Val Directive usi ua ted ninii e Foo 1L GR oe TIE Dae e 5 5 Using Built In Substitution Symbol Functions i 5 6 Recursive Substitution a i cee e 5 7 Using the Forced Substitution Operator pp 5 8 Using Subscripted Substitution Symbols to Redefine an Instruction 5 9 Using Subscripted Substitution Symbols to Find Substrings 9 5 10 The loop break endloop Directives pp 5 11 Nested Conditional Assembly Directives i 5 12 Built In Substitution Symbol Functions Used in a Conditional Assembly Code Block ies oe bed o Bodo deben Vd VORAGINE bakes 5 13 Unique Labels in a Macro sssssssssssssssss n 5 14 Producing Messages in a Macro 9 5 15 Using Nested Macros 0 5 16 Using Recursive Macros s saadet ui aa adia ta odeia ata ddi ba a dea aet dia ba aa ea a i a a A 7 1 Linker Command File os 7 2 Command File With Linker Directives 0 7 3 Th MEMORY Directive uei drea tee Qin died Lon bide Mad efe nar d 7 4 The SECTIONS Directive 5
131. Example 7 1 contains only filenames and options You can place comments in a command file by delimiting them with and To invoke the linker with this command file enter 1nk500 link cmd You can place other parameters on the command line when you use a command file lnk500 r link cmd c obj d obj The linker processes the command file as soon as it encounters it so a obj and b obj are linked into the output module before c obj and d obj You can specify multiple command files If for example you have a file called names st that contains filenames and another file called dir cmd that contains linker directives you could enter lnk500 names lst dir cmd One command file can call another command file this type of nesting is limited to 16 levels Blanks and blank lines are insignificant in a command file except as delimiters This also applies to the format of linker directives in a command file SU Note Filenames and Option Parameters With Spaces or Hyphens Within the command file filenames and option parameters containing embedded spaces or hyphens must be surrounded with quotation marks For example this file obj LLLLLLLLL L L L 3 3V Linker Command Files Example 7 2 shows a sample command file that contains linker directives Linker directive formats are discussed in later sections Example 7 2 Command File With L
132. FF concept Chapter 2 Introduction to Common Object File Format discusses COFF sections in de tail If you understand section operation you will be able to use the assembly language tools more efficiently This appendix contains technical details about COFF object file structure Much of this information pertains to the symbolic debugging information that is produced by the C C compiler The purpose of this appendix is to provide supplementary information about the internal format of COFF object files Topic Page AA GOFF bile Structuren e a AURI T one EC ELEM A File HeaderStr ct re oe ee a sn TER A 3 Optional File Header Format ence ee eens A 4 Section Header Structure cs A 7 A 5 Structuring Relocation Information LLu A 6 Line Number Table Structure ss A 12 A 7 Symbol Table Structure and Content LLLuue A 14 A 1 COFF File Structure A 1 COFF File Structure The elements of a COFF object file describe the file s sections and symbolic debugging information These elements are A file header Optional header information A table of section headers A symbol table A string table O O O O O O O L Raw data for each initialized section Relocation information for each initialized section Line number entries for each initialized section The assembler and linker produce object files with the same COFF structure however a program that is linked
133. FF object file that contains information about the symbols that are defined and used by the file tag An optional type name that can be assigned to a structure union or enumeration targetmemory Physical memory in a TMS320C54x system into which exe cutable object code is loaded text One of the default COFF sections The text section is an initialized section that contains executable code You can use the text directive to assemble code into the text section unconfigured memory Memory that is not defined as part of the memory map and cannot be loaded with code or data uninitialized section A COFF section that reserves space in the memory map but that has no actual contents These sections are built up with the bss and usect directives UNION An option of the SECTIONS directive that causes the linker to allo cate the same address to multiple sections union A variable that may hold objects of different types and sizes unsigned A kind of value that is treated as a positive number regardless of its actual sign well defined expression An expression that contains only symbols or assembly time constants that have been defined before they appear in the expression word A 16 bit addressable location in target memory assembler option linker option 7 6 in assembly language source operand prefix symbol for SPC 3 20 assembler option in assembly language source 3 14 operand pr
134. For more information about the ROMS directive see Section 10 5 The ROMS Directive on page 10 16 SECTIONS directive The SECTIONS directive specifies which sections from the COFF object file should be selected For more information about the SECTIONS directive see Section 10 6 The SECTIONS Directive on page 10 22 You can also use this directive to identify specific sections that will be initialized by an on chip boot loader For more information on the on chip boot loader see Section 10 9 3 Building a Table for an On Chip Boot Loader on page 10 29 Comments You can add comments to your command file by using the and delimiters For example This is a comment To invoke the utility and use the options you defined in a command file enter hex500 command filename You can also specify other options and files on the command line For exam ple you could invoke the utility by using both a command file and command line options hex500 firmware cmd map firmware mxp The order in which these options and file names appear is not important The utility reads all input from the command line and all information from the command file before starting the conversion process However if you are using the q option it must appear as the first option on the command line or in a command file The q option suppresses the utility s normal banner and progress informa tion Hex Conversion Utility Description 10 7
135. Header Format A 3 Optional File Header Format The linker creates the optional file header and uses it to perform relocation at download time Partially linked files do not contain optional file headers Table A 3 illustrates the optional file header format Table A 3 Optional File Header Contents Byte Number 0 1 2 3 4 7 8 11 12 15 16 19 20 23 24 27 Type Short integer Short integer Long integer Long integer Long integer Long integer Long integer Long integer Description Magic number for SunOS or HP UX it is 108h for DOS it is 801h Version stamp Size in words of executable code Size in words of initialized data sections Size in words of uninitialized bss sec tions Entry point Beginning address of executable code Beginning address of initialized data A 4 Section Header Structure Section Header Structure COFF object files contain a table of section headers that define where each section begins in the object file Each section has its own section header The COFF1 and COFF2 file types contain different section header information Table A 4 shows the section header contents for COFF1 files Table A 5 shows the section header contents for COFF2 files Table A 4 Section Header Contents for COFF1 Files Byte 0 7 8 11 12 15 16 19 20 23 24 27 28 31 32 33 34 35 36 37 38 39 Type Character Long integer Long integer Long integer Long integer Long int
136. IONS Directive Example 7 4 The SECTIONS Directive BRK KK ECC KCk KC KCk kCk kCk kCk kCk k Ck Ck k k ck Ck ck ck ck ck ck ck ckck ck ko sk e ke X ke x ke x I f Sample command file with SECTIONS directive BRK IK RRR RA KCk Ck k k k kc k Ck k Ck k k k k ck k ck ck ck ck ck ck ck sk ck ke ke X ke e ke x x f filel obj file2 0bj Input files o prog out Options SECTIONS ues directive pM text load ROM run 800h const load ROM bss load RAM vectors load FF80h section tl obj intvecl specifications t2 0bj intvec2 endvec L data align 16 Figure 7 3 shows the five output sections defined by the sections directive in Example 7 4 vectors text const bss and data Figure 7 3 Section Allocation Defined by Example 7 4 00h The bss section combines the bss sections from allocated in RAM file1 obj and file2 obj aligned on 16 word boundary The data section combines the data sections from file1 obj and file2 obj The linker will place it any where there is space for it in RAM inthis illustration y and align it to a 16 word boundary The text section combines the text sections from file1 obj and file2 obj The linker combines all sec tions named text into this section The application must relocate the section to run at 0800h allocated in ROM allocated in ROM The const se
137. LLEL memwidth 8 16 bit parallel I O bootorg PARALLEL memwidth 16 8 bit serial RS232 bootorg SERIAL memwidth 8 16 bit serial RS232 bootorg SERIAL memwidth 16 8 bit parallel EPROM bootorg 0x8000 memwidth 8 16 bit parallel EPROM bootorg 0x8000 memwidth 16 8 bit parallel bootorg WARM memwidth 8 16 bit parallel bootorg WARM memwidth 16 8 bit I O bootorg COMM memwidth 8 You should set the romwidth equal to the memwidth unless you want to have multiple output files The C54x can boot through either the serial or parallel interface with either 8 or 16 bit data The format is the same for any combination the boot table consists of a field containing the destination address a field containing the length and a block containing the data You can boot only one section If you are booting from an 8 bit channel 16 bit words are stored in the table with the MSBs first the hex conversion utility automatically builds the table in the correct format To boot from a serial port specify bootorg SERIAL when invoking the utility Use either memwidth 8 or memwidth 16 Hex Conversion Utility Description 10 33 Building a Table for an On Chip Boot Loader DD To load from a parallel I O port invoke the utility by specifying bootorg PARALLEL Use either memwidth 8 or memwiath 16 To boot from external memory EPROM specify the source address of the boot memory by using the bo
138. Macro Call DBL A OPZ add or subtract double DBL macro ABC ADDR src if Ssymcmp ABC 0 dadd ADDR src add double elseif symcmp ABC 0 dsub ADDR src subtract double else emsg Incorrect Operator Parameter endif endm For more information about conditional assembly directives see Section 4 8 Conditional Assembly Directives on page 4 20 5 16 Using Labels in Macros 5 6 Using Labels in Macros All labels in an assembly language program must be unique including labels in macros If a macro is expanded more than once its labels are defined more than once Defining labels more than once is illegal The macro language provides a method of defining labels in macros so that the labels are unique Follow the label with a question mark and the assembler replaces the question mark with a unique number When the macro is expanded you will not see the unique number in the listing file Your label appears with the question mark as it did in the macro definition You cannot declare this label as global The maximum label length is shortened to allow for the unique suffix If the macro is expanded fewer than 10 times the maximum label length is 126 characters If the macro is expanded from 10 to 99 times the maximum label length is 125 The label with its unique suffix is shown in the cross listing file The syntax for a unique label is label Example 5 13 shows uniq
139. Macro Parameter endif endm ADDX 100 macro call ADDX AR1 macro call Macro Parameters Substitution Symbols In Example 5 9 the subscripted substitution symbol is used to find a substring strg1 beginning at position start in the string strg2 The position of the substring strg1 is assigned to the substitution symbol pos Example 5 9 Using Subscripted Substitution Symbols to Find Substrings substr macro start strgl strg2 pos Var LEN1 LEN2 1 TMP lf Ssymlen start 0 eval 1 start endif eval 0 pos eval 153 eval Ssymlen strgl LEN1 eval symlen strg2 LEN2 loop break i LEN2 LEN1 1 asg strg2 i LEN1 TMP if symcmp strgl TMP 0 eval i pos break else eval xou lyi endif endloop endm asg 0 pos asg arl ar2 ar3 ar4 regs substr 1 ar2 regs pos data word pos 5 3 6 Substitution Symbols as Local Variables in Macros If you want to use substitution symbols as local variables within a macro you can use the var directive to define up to 32 local macro substitution symbols including parameters per macro The var directive creates temporary substi tution symbols with the initial value of the null string These symbols are not passed in as parameters and they are lost after expansion Var sym symo symga The var directive is used in Example 5 8 and Example 5 9 Macro Language 5 13 Macro Libra
140. NS directive alignment for must be a power of 2 Description Section alignment was not a power of 2 Action Make sure that in hexadecimal all powers of 2 consist of the integers 1 2 4 or 8 followed by a series of zero or more Os E 1 Linker Error Messages alignment for redefined Description More than one alignment is supplied for a section attempt to decrement DOT Description A statement such as value is supplied this is illegal Assignments to dot can be used only to create holes bad fill value Description The fill value must be a 16 bit constant binding address for section is outside all memory on page Description Not every section falls within memory configured with the MEMORY directive Action If you are using a linker command file check that MEMORY and SECTIONS directives allow enough room to ensure that no sections are being placed in unconfigured memory binding address for section overlays at Description Two sections overlap and cannot be allocated Action If you are using a linker command file check that MEMORY and SECTIONS directives allow enough room to ensure that no sections are being placed in unconfigured memory binding address for redefined Description More than one binding value is supplied for a section binding address incompatible with alignment for section Description The section has an alignment requireme
141. O0 OY O1 BUNE ol coo 10 21 22 23 24 25 26 27 28 29 30 31 32 33 Assemble into the text section mE ck ck kk ck ck ck ck ck ck ck ck ck ck ck ck ck ck ccc ko ko ko ko ko ko ko ke ke ko ck ck ck ck kx kx 000000 text 000000 e800 LD 0 A Allocate 4 words in bss for TEMP mom 000000 Var 1 bss TEMP 4 KR Still in text ae 000001 000 ADD 56h A 000002 0056 000003 066 MPY 73h A 000004 0073 KKK KKK KKK ck ck ck ck ck ck ck ck KKK KKK KK KKKKK KKK KK KKK KKK KK Allocate 100 words in bss for the WR symbol named ARRAY this part of ER x bss must fit on a single page
142. Precede each option with a hyphen Single letter options without parameters can be combined for example lc is equivalent to c Options that have parameters such as i must be specified separately filename appends the contents of filename to the command line You can use this option to avoid the limitations on command line length imposed by the host operating system Within a command file filenames or option parameters containing em bedded spaces or hyphens must be surrounded with quotation marks For example this file asm a C d 9 h help Invoking the Assembler creates an absolute listing When you use a the assembler does not produce an object file The a option is used in conjunction with the absolute lister makes case insignificant in the assembly language files For example c will make the sym bols ABC and abc equivalent f you do not use this option case is significant default Case signifi cance is enforced primarily with symbol names not with mnemonics and register names dname value sets the name symbol This is equivalent to inserting name set value at the beginning of the assembly file If value is omitted the symbol is set to 1 For more information see subsection 3 8 3 Defining Symbolic Constants d Option on page 3 20 suppresses the assembler s default behavior of adding a asm extension to a source file name that does
143. ROR MISSING PARAMETER 1 else 1 000000 0000 add PARAM A 1 endif 11 12 000001 MSG EX 1 VUE Ssymlen parml 0 alt emsg ERROR MISSING PARAMETER USER ERROR ERROR MISSING PARAMETER else 1 add parml A 1 endif 1 Error No Warnings In addition the following messages are sent to standard output by the assembler TMS32055xx COFF Assembler Version x xx Copyright c 2001 Texas Instruments Incorporated PASS 1 PASS 2 emsg asm ERROR at line 12 USER ERROR ERROR MISSING PARAMETER emsg ERROR MISSING PARAMETER 1 Error No Warnings Errors in source Assembler Aborted Assembler Directives 4 43 end End Assembly Syntax Description Example 4 44 The end directive is optional and terminates assembly It should be the last source statement of aprogram The assembler ignores any source statements end that follow a end directive This directive has the same effect as an end of file character You can use end when you re debugging and would like to stop assembling at a specific point in your code This example shows how the end directive terminates assembly If any source statements follow the end directive the assembler ignores them Source File START EMP T Space Set bss ABS ADD STL end byte word Listing file C0 hN mPB Oo 000000 000000 000013 000
144. RTIAL LINKER COMMAND FILE FOR FIR EXAMPLE J FCKCKOKCKCk ko kk kk kk ko kk kk kk kk ko I KOk kk ko kk Kok kk ke Kok A I ke Kok ek ke MEMORY PAGE 0 ONCHIP origin 0800h length 02400h PAGE 0 PROG origin 02C00h length 0D200h PAGE 1 DATA origin 0800h length OF800h SECTIONS text load PROG PAG fir load DATA PAG E pi fen Fl e 1 run ONCHIP PAG Specifying a Section s Runtime Address Figure 7 4 illustrates the runtime execution of this example Figure 7 4 Runtime Execution of Example 7 6 Program Memory Data Memory 800h 800h ONCHIP fir relocated fir to run here loads here 2C00h FEOOh Linker Description 7 47 Using UNION and GROUP Statements 7 10 Using UNION and GROUP Statements Two SECTIONS statements allow you to conserve memory GROUP and UNION Unioning sections causes the linker to allocate them to the same run address Grouping sections causes the linker to allocate them contiguously in memory 7 10 1 Overlaying Sections With the UNION Statement For some applications you may wantto allocate more than one section to run at the same address For example you may have several routines you want in on chip RAM at various stages of execution Or you may want several data objects that will not be active at the same time to share a block of memory The UNION statement within the SECTIONS directive prov
145. TMS320C54x Assembly Language Tools User s Guide Literature Number SPRU102E June 2001 xta PUTET TEXAS 2 SOYINK m INSTRUM ENTS Printed on Recycled Paper IMPORTANT NOTICE Texas Instruments and its subsidiaries TI reserve the right to make changes to their products orto discontinue any product or service without notice and advise customers to obtain the latest version of relevant information to verify before placing orders that information being relied on is current and complete All products are sold subject to the terms and conditions of sale supplied atthe time of order acknowledgment including those pertaining to warranty patent infringement and limitation of liability TI warrants performance of its products to the specifications applicable at the time of sale in accordance with Tl s standard warranty Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty Specific testing of all parameters of each device is not necessarily performed except those mandated by government requirements Customers are responsible for their applications using TI components In order to minimize risks associated with the customer s applications adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards TI assumes no liability for applications assistance or customer product design TI does not warrant or represent that any lic
146. That Initialize Constants 1 000000 000001 2 000002 3 000003 000004 4 000006 000007 5 000008 6 000009 00000a 7 00000c 00000d 8 00000e 00000f 000010 000011 00aa 00bb Occc 0eee efff eeee ffff dddd Sfff ffac Sftf ffac 0068 0065 006c 0070 Figure 4 3 Initialization Directives Word 0 1 2 3 4 6 7 cd e f 10 11 4 14 eo o m o o oo Co Co g m o o m m J m O D T T o m m O gt T T m ml JO e T T EL m o o T T T T o o gt gt pi T UJ a Oo o m m mio o o Oo Slo O byte word xlong long int xfloat float string mh a OAAh OBBh OEEEEFFFh ODDDDh 1 99999 1 99999 help Code byte OAAh OBBh word OCCCh Xlong OEEEEFFFh long EEEEFFFFh int DDDDh xfloat 1 99999 float 1 99999 string help Directives That Align the Section Program Counter 4 5 Directives That Align the Section Program Counter The align directive aligns the SPC at a 1 word to 128 word boundary This ensures that the code following the directive begins on an x word or page boundary If the SPC is already aligned at the selected boundary it is not incremented Operands for the align directive must equal a power of 2 between 20 and 216 although directives beyond 27 are not meaningful For example Operand of 1 aligns SPC to word boundary 2 aligns SPC to lo
147. The compiler begins numbering these symbol names at 0 Symbol Table Structure and Content A 7 1 1 Symbols and Blocks In C a block is a compound statement that begins and ends with braces A block always contains symbols The symbol definitions for any particular block are grouped together in the symbol table and are delineated by the bb eb special symbols Blocks can be nested in C and their symbol table entries can be nested correspondingly Figure A 7 shows how block symbols are grouped in the symbol table Figure A 7 Symbols for Blocks Symbol Table Block 1 bb symbols for block 1 eb Block 2 bb symbols for block 2 eb A 7 1 2 Symbols and Functions The symbol definitions for a function appear in the symbol table as a group delineated by bf ef special symbols The symbol table entry for the function name precedes the bf special symbol Figure A 8 shows the format of symbol table entries for a function Figure A 8 Symbols for Functions function name b symbols for the function If a function returns a structure or union a symbol table entry for the special symbol target will appear between the entries for the function name and the bf special symbol Common Object File Format A 17 Symbol Table Structure and Content A 7 2 Symbol Name Format The first eight bytes of a symbol table entry bytes 0 7 indicate a symbol s name Ifthe symbol name is eig
148. To do this specify a set of attributes enclosed in parentheses instead of a memory name Using the same MEMORY directive declaration you can specify SECTIONS text gt X text executable memory data gt RI data read or init memory bss gt RW bss read or write memory In this example the text output section can be linked into either the ROM or RAM area because both areas have the X attribute The data section can also go into either ROM or RAM because both areas have the R and attributes The bss output section however must go into the RAM area because only RAM is declared with the W attribute You cannot control where in a named memory range a section is allocated although the linker uses lower memory addresses first and avoids fragmenta tion when possible In the preceding examples assuming that no conflicting assignments exist the text section would start at address O If a section must start on a specific address use binding instead of named memory Linker Description 7 37 The SECTIONS Directive 7 8 3 3 Alignment and blocking You can tell the linker to place an output section at an address that falls on an n word boundary where n is a power of 2 For example text load align 128 allocates text so that it falls on a 128 word boundary Blocking is a weaker form of alignment that allocates a section anywhere within a block of size n If the section is
149. Union tag C AUTO 1 Automatic variable C TPDEF 13 Type definition C EXT 2 External symbol C USTATIC 14 Uninitialized static C STAT 3 Static C ENTAG 15 Enumeration tag C REG 4 Register variable C MOE 16 Member of an enumeration C EXTREF 5 External definition C REGPARM 17 Register parameter C LABEL 6 Label C FIELD 18 Bit field C ULABEL 7 Undefined label C BLOCK 100 Beginning or end of a block used only for the bb and eb special symbols C MOS 8 Member of a structure C FON 101 Beginning or end of a func tion used only for the bf and ef special symbols C ARG 9 Function argument C EOS 102 End of structure used only for the eos special symbol C STRTAG 10 Structure tag C FILE 103 Filename used only for the file special symbol C MOU 11 Member of a union C LINE 104 Used only by utility programs Some special symbols are restricted to certain storage classes Table A 13 lists these symbols and their storage classes Common Object File Format A 19 Symbol Table Structure and Content Table A 13 Special Symbols and Their Storage Classes Special Restricted to This Special Restricted to This Symbol Storage Class Symbol Storage Class file C_FILE eos C EOS bb C_BLOCK text C_STAT eb C BLOCK data C STAT bf C FON bss C STAT ef C FON A 7 5 Symbol Values Bytes 8 11 of a symbol table entry indicate a symbol s value A symbol s value depends on the symbol s storage class Table A 14 summarizes the storage class
150. Unsigned short integer Version ID indicates version of COFF file structure 2 3 Unsigned short integer Number of section headers 4 7 Long integer Time and date stamp indicates when the file was created 8 11 Long integer File pointer contains the symbol table s starting address 12 15 Long integer Number of entries in the symbol table 16 17 Unsigned short integer Number of bytes in the optional header This field is either 0 or 28 if itis 0 then there is no optional file header 18 19 Unsigned short integer Flags see Table A 2 20 21 Unsigned short integer Target ID magic number indicates the file can be executed in a TMS320C54x system Table A 2 lists the flags that can appear in bytes 18 and 19 of the file header Any number and combination of these flags can be set at the same time for example if bytes 18 and 19 are set to 0003h F RELFLG and F EXEC are both set Table A 2 File Header Flags Bytes 18 and 19 Mnemonic Flag Description F RELFLG 0001h Relocation information was stripped from the file F EXEC 0002h The file is relocatable it contains no unresolved external references F LNNO 0004h Line numbers were stripped from the file F LSYMS 0008h Local symbols were stripped from the file F LITTLE 0100h The file has the byte ordering used by C54x devices 16 bits per word least significant byte first F SYMMERGE 1000h Duplicate symbols were removed Common Object File Format A 5 Optional File
151. Works With Macros This section describes how the translator works with macros The following subjects are discussed Directives in macros Macro local variables Defining labels when invoking a macro 11 5 1 Directives in Macros When macro invocations are expanded directives in macro definitions are not copied to the intermediate file Instead the macro is inlined and the code is no longer in a macro environment The following source code preprocesses to the intermediate code as shown Example 11 3 Directives in Macros a Source code mymac macro parml var temp eval parml temp word temp endm mymac 5 b Intermediate code mymac macro parml Var temp eval parml temp word temp endm mymac 5 word 5 11 8 How the Translator Works With Macros 11 5 2 Macro Local Variables When macro local variables are encountered they are changed so that repeated calls to the macro do not generate identical labels The following Source code preprocesses to the intermediate code as shown Example 11 4 Macro Local Variables a Source code mymac macro parmi lab word parmi endm mymac 4 mymac 40 mymac 400 b Intermediate code mymac macro parml lab word parmi endm mymac 4 lab 1 word 4 mymac 40 lab 2 word 40 mymac 400 lab 3 word 400 Thelocallabelnameis appended with n where nis the number of the macro invoca
152. Y flag 0010h is set in the cinit section header STYP COPY is the special attribute that tells the loader to perform autoinitialization directly and notto load the cinit section into memory The linker does not allocate space in memory for the cinit section Linker Description 7 75 Linker Example 7 18 Linker Example 7 76 This example links three object files named demo obj fft obj and tables obj and creates a program called demo out The symbol SETUP is the program entry point Assume that target memory has the following configuration Program Memory Address Range Contents 0080 to 7000 On chip RAM PG C000 to FF80 On chip ROM Data Memory Address Range Contents 0080 to OFFF RAM block ONCHIP 0060 to FFFF Mapped external addresses EXT The output sections are constructed from the following input sections m m Executable code contained in the text sections of demo obj fft obj and tables obj must be linked into program ROM Variables contained in the var_defs section of demo obj must be linked into data memory in block ONCHIP Tables of coefficients in the data sections of demo obj tables obj and fft obj must be linked into RAM block ONCHIP in data memory A hole is created with a length of 100 words and a fill value of 07A1Ch The remain der of block ONCHIP must be initialized to the value 07A1Ch The bss sections from demo obj tables obj and fft obj which contain variables must be linked into
153. a newvars 30 eight words 31 reserved How the Linker Handles Sections 2 4 How the Linker Handles Sections The linker has two main functions related to sections First the linker uses the sections in COFF object files as building blocks it combines input sections when more than one file is being linked to create output sections in an execut able COFF output module Second the linker chooses memory addresses for the output sections Two linker directives support these functions J The MEMORY directive allows you to define the memory map of a target system You can name portions of memory and specify their starting addresses and their lengths J The SECTIONS directive tells the linker how to combine input sections into output sections and where to place these output sections in memory Subsections allow you to manipulate sections with greater precision You can specify subsections with the linker s SECTIONS directive If you do not specify asubsection explicitly then the subsection is combined with the other sections with the same base section name It is not always necessary to use linker directives If you don t use them the linker uses the target processor s default allocation algorithm described in Section 7 12 Default Allocation Algorithm on page 7 58 When you do use linker directives you must specify them in a linker command file Referto the following sections for more information about linker command files and l
154. a 16 bit processor has a 16 bit memory architecture However some applica tions require target words to be broken up into multiple consecutive narrower memory words Moreover with certain processors like the C54x the memory width can be narrower than the target width The hex conversion utility defaults memory width to the target width in this case 16 bits You can change the memory width by DD Using the memwidth option This changes the memory width value for the entire file Setting the memwidth parameter of the ROMS directive This changes the memory width value for the address range specified in the ROMS directive and overrides the memwidth option for that range See Section 10 5 The ROMS Directive on page 10 16 For both methods use a value that is a power of 2 greater than or equal to 8 You should change the memory width default value of 16 only in exceptional situations for example when you need to break single target words into consecutive narrower memory words Situations in which memory words are narrower than target words are most common when you use an on chip boot loader that supports booting from narrower memory For example a 16 bit TMS320C54x can be booted from 8 bit memory or an 8 bit serial port with each 16 bit value occupying two memory locations this would be specified as memwidth 8 Understanding Memory Widths Figure 10 3 demonstrates how the memory width is related to the data wid
155. able and absolute sym bols These examples use four symbols that are defined in the same section global extern 1 Defined in an external module intern 1 word D Relocatable defined in current module LAB1 set 2 LABI 2 intern_2 Relocatable defined in current module Example 1 The statements in this example use an absolute symbol LAB1 which is defined above to have a value of 2 The first statement loads the value 51 into the accumulator LD LAB1 443 7 A ACC A LD 4LABl 4 3 7 A ACC A SL 27 Expressions Example 2 All legal expressions can be reduced to one of two forms relocatable symbol absolute symbol or absolute value Unary operators can be applied only to absolute values they cannot be applied to relocatable symbols Expressions that cannot be reduced to contain only one relocatable symbol are illegal The first statement in the following example is valid the statements that follow it are invalid LD extern 1 10 B Legal LD 10 extern 1 B Can t negate reloc symbol LD intern 1 B Can t negate reloc symbol P d LD extern_1 10 B isn t additive operator LD intern 1 extern 1 B Multiple relocatables Example 3 The first statement below is legal although intern 1 and intern 2 are relocatable their difference is absolute because they re in the same section Subtracting one relocatable symbol from another reduces the expression to relocatable symbo
156. ables The assembler assumes that text is the default section Therefore at the beginning of an assembly the assembler assembles code into the text section unless you use a section control directive For more information about COFF sections see Chapter 2 Introduction to Common Object File Format In this example code is assembled into the data and text sections 1 coco ck ck ck ck ck ck ck Ck 0k 0k ck Ck 0k 00 kk kk kk ko kk ck ck ck ck ck ck KK ck ck ko A AX 2 Reserve space in data Ws 3 koc ck ck ck ck ck ck 0k ck ck 0k 0k 0k 0k 0k 0k 0k kk kk kk ck ck ck ck ck ck Ck Pk kx kx o 4 000000 data 5 000000 Space 0CCh 6 7 koc ok ok ck ck ck ck ck ck KKK ck ck 0k 00k kk kk ko kk kk ck ck ck ck ck ck ck kc ck ck ko ko AX 8 Assemble into text m 9 ck cock ck ck ck ck ck ck ck KKK 0k 0k 0k 00K ck kk kk kk ck ck ck ck ck ck Ck Ck kx x o 10 000000 text 11 0000 INDEX set 0 12 000000 e800 LD INDEX A 13 14 ck ck ck ck ck ck ck ck ck ck KKK KKK KK KKK KKK kk kk kk ck ck ck KKK KKK KKK 15 Assemble into data pm 16 17 00000c Table data 18 00000d ffff word e Assemble 16 bit 19 constant into data 20 00000e OO0ff byte OFFh Assemble 8 bit 21 constant into data 22 23 ck cc ck ck ck ck ck ck ck ck 0k 0k 0k 0k 0k 00k kk kk ck ck ck ck ck ck ck c
157. ace size in bits String string stringg ubyte value value uchar value valuen uhalf value valuen ushort value value Uint value valuen ulong value valuen uword value values Word value valuen Xfloat value values Xlong value value Description Reserve size bits in the current section note that a label points to the last addressable word in the reserved space Initialize one or more successive words in the current section Initialize one or more 64 bit IEEE double precision floating point constants Initialize a variable length field Initialize one or more 32 bit IEEE single precision floating point constants Initialize one or more 16 bit integers Initialize one or more 16 bit integers Initialize one or more 32 bit integers Initialize one or more text strings packed Reserve size bits in the current section note that a label points to the beginning of the reserved space Initialize one or more text strings Initialize one or more successive words in the current section Initialize one or more unsigned 16 bit integers Initialize one or more unsigned 16 bit integers Initialize one or more unsigned 32 bit integers Initialize one or more unsigned16 bit integers Initialize one or more 16 bit integers Initialize one or more 32 bit IEEE single precision floating point constant
158. addr value sname paddrzboot sname boot The SECTIONS Directive SECTIONS begins the directive definition sname identifies a section in the COFF input file If you specify a sec tion that doesn t exist the utility issues a warning and ignores the name paddr specifies the physical ROM address at which this section should be located This value overrides the section load address given by the linker See Section 10 10 Controlling the ROM Device Address on page 10 35 This value must be a decimal octal or hexadecimal constant It can also be the word boot to indicate a boot table section for use with the on chip boot loader f your file contains multiple sections and if one section uses a padar parameter then all sections must use a padar parameter z boot configures a section for loading by the on chip boot loader This is equivalentto using paddrzboot Boot sections have a physi cal address determined both by the target processor type and by the various boot loader specific command line options The commas separating section names are optional For more similarity with the linker s SECTIONS directive you can use colons after the section names in place of the equal sign on the boot keyboard For example the following statements are equivalent SECTIONS text data boot SECTIONS text data boot In the example below the COFF file contains six initialized sections text data
159. ader uses a special table a boot table stored in memory such as EPROM or loaded from a device peripheral such as a serial or communications port to initialize the code or data The hex conversion utility supports the boot loader by auto matically building the boot table 10 9 1 Description of the Boot Table The input for a boot loader is the boot table The boot table contains records that instruct the on chip loader to copy blocks of data contained in the table to specified destination addresses Some boot tables also contain values for ini tializing various processor control registers The boot table can be stored in memory or read in through a device peripheral The hex conversion utility automatically builds the boot table for the boot loader Using the utility you specify the COFF sections you want the boot loader to initialize the table location and the values for any control registers The hex conversion utility identifies the target device type from the COFF file builds a complete image of the table according to the format required by that device and converts it into hexadecimal in the output files Then you can burn the table into ROM or load it by other means The boot loader supports loading from memory that is narrower than the nor mal width of memory For example you can boot a 16 bit TMS320C54x from a single 8 bit EPROM by using the memwidth option to configure the width of the boot table The hex conversion utility
160. adr Defining Macros Example 5 1 Macro Definition Call and Expansion Continued b Algebraic example al 2 3 add3 4 5 ADDRP Pl P2 P3 6 7 add3 macro P1 P2 P3 ADDRP 8 9 A QP1 10 A A P2 11 A A P3 12 ADDRP A 13 endm 14 15 16 global abc def ghi adr 17 18 000000 add3 abc def ghi adr 1 1 000000 1000 A abc 1 000001 0000 A A def 1 000002 0000 A A ghi 1 000003 8000 Qadr A Macro Language 5 5 Macro Parameters Substitution Symbols 5 3 Macro Parameters Substitution Symbols If you wantto call a macro several times with different data each time you can assign parameters within the macro The macro language supports a special symbol called a substitution symbol which is used for macro parameters Macro parameters are substitution symbols that represent a character string These symbols can also be used outside of macros to equate a character string to a symbol name Valid substitution symbols can be up to 32 characters long and must begin with a letter The remainder of the symbol can be a combination of alphanumeric characters underscores and dollar signs Substitution symbols used as macro parameters are local to the macro they are defined in You can define up to 32 local substitution symbols including substitution symbols defined with the var directive per macro For more information about the var directive see subsection 5 3 6 Sub
161. age and listing files for code with and without the conditional blocks listed Source File AAA set 1 BBB set 0 fclist if AAA ADD 1024 A else ADD 1024 10 A endif fcnolist if AAA ADD 1024 A else ADD 1024 10 A endif Listing file 1 0001 AAA set 1 2 0000 BBB set 0 3 fclist 4 if AAA 5 000000 F000 ADD 1024 A 000001 0400 6 else 7 ADD 1024 10 A 8 endif 9 10 fcnolist 11 13 000002 F000 ADD 1024 A 000003 0400 4 46 Syntax Description Initialize Field field field value size in bits The field directive can initialize multiple bit fields within a single word of memory This directive has two operands DD The valueis arequired parameter itis an expression that is evaluated and placed in the field If the value is relocatable size must be 16 L The sizeis an optional parameter it specifies a number from 1 to 32 which is the number of bits in the field If you do not specify a size the assembler assumes that the size is 16 bits If you specify a size of 16 or more the field will start on a word boundary If you specify a value that cannot fit into size bits the assembler truncates the value and issues an error message For example field 3 1 causes the assembler to truncate the value 3 to 1 the assembler also prints the message warning value truncated Successive field directives pack values into the specified number of bits start ing at the current word Fields ar
162. aic directive tells the assembler that this file contains algebraic assembly source code This directive must be the first line in the file if the mg option is not used M UM a Note Mixing Algebraic and Mnemonic Assembly Code Algebraic and mnemonic assembly code cannot be mixed within the same source file The algebraic directive does not provide a method for mixing algebraic and mnemonic statements within the same source file It provides a means of selecting algebraic assembly without specifying the mg assembler option Syntax Description Example Align SPC on a Boundary align even align size even The align directive aligns the section program counter SPC on the next boundary depending on the size parameter The size may be any power of 2 although only certain values are useful for alignment An operand of 128 aligns the SPC on the next page boundary and this is the default if no size is given The assembler assembles words containing null values 0 up to the next x word boundary Operand of 1 aligns SPC to word boundary 2 aligns SPC to long word even boundary 128 aligns SPC to page boundary The even directive aligns the SPC on a long word even boundary This direc tive is equivalent to the align directive with an operand of 2 Using the align directive has two effects The assembler aligns the SPC on a boundary within the current section Theassembler sets a flag that forces the
163. al element is one of the following descriptors byte char double field float half int long short string ubyte uchar uhalt uint ulong ushort uword and word An element can also be a com plete declaration of a nested structure or union or a structure or union declared by its tag Following a struct directive these directives describe the element s size They do not allocate memory expin is an optional expression for the number of elements described This value defaults to 1 A string elementis considered to be one word in size and a field element is one bit size is an optional label for the total size of the structure I Note Directives That Can Appear in a struct endstruct Sequence The only directives that can appear in a struct endstruct sequence are ele ment descriptors structure and union tags conditional assembly directives and the align directive which aligns the member offsets on word bound aries Empty structures are illegal st These examples show various uses of the struct tag and endstruct directives Assembler Directives 4 87 struct endstruct tag Declare Structure Types Example 1 al REAL_REC struct 2 0000 NOM int 3 0001 DEN link 4 0002 REAL LEN endstruct 5 6 000000 0001 ADD REAL REAL REC 7 8 9 000000 bss REAL REAL LEN Example 2 10 CPLX REC struct T 0000 REALI tag REAL REC 12 0002 IM
164. al symbols that are generated by the compiler assembler and linker Each special symbol contains ordinary symbol table information as well as an auxiliary entry Table A 11 lists these symbols Special Symbols in the Symbol Table Symbol Description file File name text Address of the text section data Address of the data section bss Address of the bss section bb Address of the beginning of a block eb Address of the end of a block bf Address of the beginning of a function ef Address of the end of a function target Pointer to a structure or union that is returned by a function nfake Dummy tag name for a structure union or enumeration eos End of a structure union or enumeration etext Next available address after the end of the text output section edata Next available address after the end of the data output section end Next available address after the end of the bss output section Several of these symbols appear in pairs DD bb eb indicate the beginning and end of a block bf ef indicate the beginning and end of a function DD nfake eos name and define the limits of structures unions and enumera tions that were not named The eos symbol is also paired with named structures unions and enumerations When a structure union or enumeration has no tag name the compiler assigns it a name so that it can be entered into the symbol table These names are of the form nfake where nis an integer
165. allocated however the second block cannot fit on the current page As Figure 4 5 shows the second block is allocated on the next page Figure 4 5 Allocating bss Blocks Within a Page Memory 0a Memory allocated by first bss direc tive 64 words left in the first page Hole in memory left because second bss directive required more than 64 Page words boundary 127 b Memory allocated by second bss di rective 58 words left in the second page Unused memory 256 Section directives for initialized sections text data and sect end the cur rent section and begin assembling into another section The bss directive however does not affect the current section The assembler assembles the bss directive and then resumes assembling code into the current section For more information about COFF sections see Chapter 2 Introduction to Common Object File Format Assembler Directives 4 31 DSS Reserve Space in the bss Section Example 4 32 In this example the bss directive is used to allocate space for two variables TEMP and ARRAY The symbol TEMP points to 4 words of uninitialized space at bss SPC 0 The symbol ARRAY points to 100 words of uninitialized space at bss SPC 04h this space must be allocated contiguously within a page Note that symbols declared with the bss directive can be referenced in the same manner as other symbols and can also be declared external J C0 NO P5 O Xo
166. alue for filling the holes between sections The fill value must be specified as an integer constant following the fill option The width of the constant is assumed to be that of a word on the target processor For example for the C54x specifying fill OFFh results in a fill pattern of OOFFh The constant value is not sign extended The hex conversion utility uses a default fill value of zero if you don t specify a value with the fill option The fill option is valid only when you use image otherwise it is ignored 10 8 3 Steps to Follow in Image Mode Step 1 Define the ranges of target memory with a ROMS directive See Section 10 5 The ROMS Directive on page 10 16 for details Step 2 Invoke the hex conversion utility with the image option To number the bytes sequentially use the byte option to reset the address origin to zero for each output file use the zero option See subsection 10 10 3 The byte Option on page 10 37 for details on the byte option and page 10 36 for details on the zero option If you don t specify a fill value with the ROMS directive and you want a value other than the default of zero use the fill option Hex Conversion Utility Description 10 27 Building a Table for an On Chip Boot Loader 10 9 Building a Table for an On Chip Boot Loader Some DSP devices such as the C54x have a built in boot loader that initial izes memory with one or more blocks of code or data The boot lo
167. an also be used to split an output section among all memory ranges that match a specified attribute combination For example MEMORY P_MEM1 RWX origin 01000h length 02000h P_MEM2 RWI origin 04000h length 01000h SECTIONS text text gt gt RW The linker will attempt to allocate all or part of the output section into any memory range whose attributes match the attributes specified in the SECTIONS directive This SECTIONS directive has the same effect as SECTIONS text text gt gt P_MEM1 P MEM2 Certain output sections should not be split cinit which contains the autoinitialization table for C C programs pinit which contains the list of global constructors for C programs an output section with separate load and run allocations The code that copies the output section from its load time allocation to its run time loca tion cannot accommodate a split in the output section an output section with an input section specification that includes an ex pression to be evaluated The expression may define a symbol that is used in the program to manage the output section at run time If you use the gt gt operator on any of these sections the linker will issue a warn ing and ignore the operator The SECTIONS Directive 7 8 8 7 Allocating an Archive Member to an Output Section The linker allows you to allocate one or more members of an arch
168. and must be en closed in double quotes A section name can contain a subsection name in the form of section name subsection name The STYP_CLINK flag tells the linker to leave the section out of the final COFF output of the linker if there are no references found to any symbol in the section A section in which the entry point of a C program is defined cannot be marked as a conditionally linked section In this example the Vars and Counts sections are set for conditional linking 1 000000 sect Vars 2 Vars section is conditionally linked 3 clink 4 5 000000 001A X word 01Ah 6 000001 001A Y word 01Ah 7 000002 001A 2 word 01Ah 8 000000 sect Counts 9 Counts section is conditionally linked 0 clink 1 2 000000 001A Xcount word 01Ah 3 000001 001A Ycount word 01Ah 14 000002 001A Zcount word 01Ah 15 By default text is unconditionally linked 6 000000 text 7 Reference to symbol X cause the Vars section 8 to be linked into the COFF output 19 000000 E800 LD 0 A 20 000001 8000 STL A X Syntax Description Specify C Runtime Environment c mode c mode The c mode directive is generated as a header for any assembly file created by the C compiler This directive works primarily in conjunction with the mf assembler option or the far mode directive to facilitate linking a program that uses extended addressing If your program uses extended addressing but your assembly cod
169. and then link the module in directly DD Include rts lib as an input file the linker automatically extracts boot obj when you use the c or cr option 7 17 2 Object Libraries and Runtime Support The TMS320C54x Optimizing C Compiler User s Guide describes additional runtime support functions that are included in rts lib If your program uses any of these functions you must link rts lib with your object files You can also create your own object libraries and linkthem The linker includes and links only those library members that resolve undefined references Linking C C Code 7 17 3 Setting the Size of the Stack and Heap Sections C uses two uninitialized sections called sysmem and stack for the memory pool used by the malloc functions and the runtime stack respectively You can set the size of these by using the heap option or stack option and speci fying the size of the section as a constant immediately after the option The default size for both is 1K words For more information see subsection 7 4 8 Define Heap Size heap constant Option on page 7 12 or subsection 7 4 16 Define Stack Size stack constant Option on page 7 18 7 17 4 Autoinitialization ROM and RAM Models The C C compiler produces tables of data for autoinitializing global vari ables These are in a named section called cinit The initialization tables can be used in either of two ways J RAM Model cr option Variable
170. anslator requires error free code When the translator encounters unrecognized instructions or macro invocations it prints a message to stan dard output and does not translate the line of code The translator accepts assembly code source files containing mnemonic instructions and produces assembly code source files containing algebraic instructions The input file can have no extension or an extension of asm The output file will have the same name as the input file with an extension of cnv 11 1 1 What the Translator Does The translator accomplishes the following Replaces a mnemonic with an algebraic representation of what the instruction does as defined by the language specifications The algebraic representation might consist of more than one line of code Reformats mnemonic instruction operands into algebraic syntax as de scribed in the language specifications This reformatting includes the following m Data memory address dma accesses are prefixed with a symbol B The mnemonic indirect shorthand is replaced with ARO m When necessary constants are prefixed with a symbol E Algebraic expressions that are used as a single operand and have more than one term are enclosed in parentheses 11 1 2 What the Translator Does Not Do 11 2 The translator has the following limitations Thetranslator cannot convert macro definitions It ignores them Optional ly the translator replaces macro invocations with the
171. appear as operands for the macro directive Parameters are discussed in Section 5 3 Macro Parameters Substitution Symbols on page 5 6 model statements are instructions or assembler directives that are executed each time the macro is called macro directives are used to control macro expansion mexit functions as a goto endm statement The mexit directive is useful when error testing confirms that macro expansion will failand completing the rest of the macro is unnecessary endm terminates the macro definition Macro Language 5 3 Defining Macros Example 5 1 Macro Definition Call and Expansion 5 4 If you want to include comments with your macro definition but do not want those comments to appear in the macro expansion use an exclamation point to precede your comments If you do want your comments to appear in the macro expansion use an asterisk or semicolon For more information about macro comments see Section 5 7 Producing Messages in Macros on page 5 19 Example 5 1 shows the definition call and expansion of a macro a Mnemonic example cO 1001 CO OIL OO i000 10 01 iS CO IND S 000000 000000 1000 000001 0000 000002 0000 000003 8000 PRPPRPR add3 add3 ADDRP Pl P2 P3 macro Pl P2 P3 ADDRP LD ADD ADD STL endm Pl A P2 A P3 A A ADDRP global abc def ghi adr add3 abc def ghi adr LD ADD ADD STL abc A def A ghi A A
172. as initialized This means that the object file contains the actual memory image contents of the section When the section is loaded this image is loaded into memory at the section s speci fied starting address The text and data sections always have raw data if any thing was assembled into them Named sections defined with the sect assem bler directive also have raw data By default the bss section and sections defined with the usect directive have no raw data they are uninitialized They occupy space in the memory map but have no actual contents Uninitialized sections typically reserve space in RAM for variables In the object file an uninitialized section has a normal sec tion header and may have symbols defined in it however no memory image is stored in the section 7 15 2 Creating Holes You can create a hole in an initialized output section A hole is created when you force the linker to leave extra space between input sections within an out put section When such a hole is created the linker must follow the first guide line above and supply raw data for the hole Holes can be created only within output sections Space can exist between output sections but such space is not holes There is no way to fill or initialize the space between output sections with the SECTIONS directive To create a hole in an output section you must use a special type of linker assignment statement within an output section definition The a
173. at the width of each value is restricted to 8 bits The field directive places a single value into a specified number of bits in the current word With field you can pack multiple fields into a single word the assembler does not increment the SPC until a word is filled Figure 4 2 shows how fields are packed into a word For this example assume the following code has been assembled notice that the SPC doesn t change for the first three fields the fields are packed into the same word 4 000000 6000 field 5 000000 6400 field 6 000000 6440 field 7 000001 0123 field 000002 4000 8 000003 0000 field 000004 1234 Figure 4 2 The field Directive 15 141 V 3 bits 15 12 1 15 00000001008 15 010000000000000 15 000000000000000 15 000100100041 1010 0001 u 3 8 6 Le 5 01234h 20 01234h 32 field 3 3 field 8 6 field 16 5 field 01234h 20 field 01234h 32 float and xfloat calculate the single precision 32 bit IEEE floating point representation of a single floating point value and store it in two con Directives That Initialize Constants secutive words in the current section The most significant word is stored first The float directive automatically aligns to the nearest long word boundary and xfloat does not G int uint half uhalf short ushort word and uword place one or more 16 bit values into consecutive words in the current se
174. ation of filenames on the command line and the names of the output files They should always precede any filename on the command line Absolute Lister Description 8 3 Invoking the Absolute Lister The e options are useful when the linked object file was created from C files compiled with the debugging option g compiler option When the debugging option is set the resulting linked object file contains the name of the source files used to build it In this case the absolute lister will not generate a corresponding abs file for the C header files Also the abs file corresponding to a C source file will use the assembly file generated from the C source file rather than the C source file itself For example suppose the C source file hello csr is compiled with debugging set this generates the assembly file hello s hello csr also includes hello hsr Assuming the executable file created is called hello out the following command will generate the proper abs file abs500 ea s ec csr eh hsr hello out An abs file will not be created for hello hsr the header file and hello abs will include the assembly file hello s not the C source file hello csr Absolute Lister Example 8 3 Absolute Lister Example This example uses three source files module1 asm and module2 asm both include the file globals def module1 asm text bss array 100 bss dflag 2 Copy globals def ld offset A id dflag A module2 asm bss off
175. automatically adjusts the table s format and length See the boot loader example in the TMS320C54x DSP Ref erence Set for an illustration of a boot table 10 9 2 The Boot Table Format 10 28 The boot table format is simple Typically there is a header record containing values for various control registers Each subsequent block has a header con taining the size and destination address of the block followed by data for the block Multiple blocks can be entered a termination block follows the last block Finally the table can have a footer containing more control register val ues See the boot loader section in the 7MSS20C54x DSP Reference Set for more information 10 9 3 How to Build the Boot Table Building a Table for an On Chip Boot Loader Table 10 2 summarizes the hex conversion utility options available for the boot loader Table 10 2 Boot Loader Options a Options for all C54x devices Option boot bootorg PARALLEL bootorg SERIAL bootorg value bootpage value e value Description Convert all sections into bootable form use instead of a SECTIONS directive Specify the source of the boot loader table as the parallel port Specify the source of the boot loader table as the serial port Specify the source address of the boot loader table Specify the target page number of the boot loader table Specify the entry point at which to begin execution after boot loading The value can be a
176. away from the instruction Introduction to Common Object File Format 2 17 Helocation 2 18 Similarly if an instruction with an absolute address field contains a reference to a symbol label or address the referenced item is expected to be located at an address that will fit in the instruction s field For example if a function is linked at 0x10000 its address cannot be encoded into a 16 bit instruction field In both cases the linker truncates the high bits of the value To deal with these issues examine your link map and linker command file You may be able to rearrange output sections to put referenced symbols closer to the referencing instruction Alternatively consider using a different assembly instruction with a wider field Or if you only need the lower bits of a symbol use a mask expression to mask off the lower bits Runtime Relocation 2 6 Runtime Relocation At times you may want to load code into one area of memory and run it in another For example you may have performance critical code in a ROM based system The code must be loaded into ROM but it would run faster in RAM The linker provides a simple way to handle this Using the SECTIONS directive you can optionally direct the linker to allocate a section twice first to set its load address and again to set its run address Use the load keyword for the load address and the run keyword for the run address The load address determines where a loader w
177. ax Description Example Initialize Floating Point Value float value valuen Xfloat value valuen The float and xfloat directives place the floating point representation of one or more floating point constants into the current data section The value must be a floating point constant or a symbol that has been equated to a floating point constant Each constant is converted to a floating point value in IEEE single precision 32 bit format Floating point constants are aligned on the long word boundaries unless the xfloat directive is used The xfloat directive performs the same function as the float directive but does not align the result on the long word boundary The 32 bit value consists of three fields Field Meaning s A 1 bit sign field e An 8 bit biased exponent f A 23 bit mantissa The value is stored most significant word first least significant word second in the following format 31 30 23 22 0 pp vq YT When you use floatin a struct endstruct sequence float defines a member s size it does not initialize memory For more information about struct endstruct see Section 4 9 Assembly Time Symbol Directives on page 4 21 This example shows the float directive 1 000000 E904 float 1 0e25 000001 5951 2 000002 4040 float 3 000003 0000 3 000004 42F6 float 123 000005 0000 Syntax Description Example Identify Global Symbols global def ref global symbol
178. b7 CONTENTS 00000000 00000138 BOOT TABLE boot sec dest 00001400 size 00000139 width 00000002 The hex conversion utility output file boot hex resulting from the command file in Example C 10 is shown in Example C 12 Example C 12 Hex Conversion Utility Output File Resulting From the Command File in Example C 10 200000001400007976F800800005FC00771800A66BF8001803FF68F80018FFFEF7B8F7BED9 20002000F4A0F6B7F6B5F6B6F020146DF1000001F84D142BF07314257EF80012F00000010C 2000400047F800117E9200F80011F00000017EF80011F00000016C89141AF0741400F074CF 2000600014674A117211008410F80011FA4514444A16EEFF4811F00000868816F495F49527 2000800010E EFFFFFAES36CE9FFFF143EI10F80085F845144B10F80085F4E3F495F073144COF 2000C000801 00000001FF 2000A000F7B811F80084F3100020FA4B145BF4954A11F2731465F495E80172110084491198 E10086F3000001E80081F800848Al1FCOOEEFFE801F074142FEEO01FC0000045D 1800E00000800001000200030004000100840000000100850000000073 C 16 Example 4 Generating a Boot Table for LP Core Devices C 5 Example 4 Generating a Boot Table for LP Core Devices Example 4 shows how to use the linker and the hex conversion utility to build a boot load table for the C54xLP devices For the C54xLP devices you can specify multiple sections It is not necessary therefore to group sections at link time as with the non LP d
179. beginning of the tables in memory When the program begins running the C C boot routine copies data from the tables into the specified variables in the bss section This allows initialization data to be stored in ROM and copied to RAM each time the program is started Figure 7 8 illustrates the ROM autoinitialization model Figure 7 8 ROM Model of Autoinitialization 7 74 ObjectFile Memory Initialization tables possibly ROM routine Linking C C Code 7 17 5 The c and cr Linker Options The following list outlines what happens when you invoke the linker with the c or cr option d m The symbol _c_int00 is defined as the program entry point _c_int00 is the start of the C C boot routine in boot obj referencing _c_int00 ensures that boot obj is automatically linked in from the runtime support library rts lib The cinit output section is padded with a termination record to designate to the boot routine ROM model or the loader RAM model when to stop reading the initialization tables In the ROM model c option the linker defines the symbol cinit as the starting address of the cinit section The C C boot routine uses this symbol as the starting point for autoinitialization In the RAM model cr option B The linker sets the symbol cinit to 1 This indicates that the initialization tables are not in memory so no initialization is performed at runtime m The STYP COP
180. bined to form a bss output section The bss section is allocated into configured memory on PAGE 1 which is the data memory space If the input files contain initialized named sections the linker allocates them into program memory following the data section If the input files contain uninitialized named sections the linker allocates them into data memory fol lowing the bss section You can override this by specifying an explicit PAGE in the SECTIONS directive If you use a SECTIONS directive the linker performs no part of the default allocation Allocation is performed according to the rules specified by the SECTIONS directive and the general algorithm described in subsection 7 12 2 General Rules for Output Sections Default Allocation Algorithm 7 12 2 General Rules for Output Sections An output section can be formed in one of two ways Rule 1 As the result of a SECTIONS directive definition Rule 2 By combining input sections with the same names into an out put section that is not defined in a SECTIONS directive If an output section is formed as a result of a SECTIONS directive rule 1 this definition completely determines the section s contents See Section 7 8 The SECTIONS Directive on page 7 32 for examples of how to define an output section s content An output section can also be formed when input sections are not specified by a SECTIONS directive rule 2 In this case the linker combines all such input sections
181. ble below shows the directories that r lib and lib2 lib reside in how to set environment variable and how to use both libraries during a link Select the row for your operating system Operating System Pathname Invocation Command DOS UNIX 7 14 Md and Id2 1nk500 fl obj f2 0bj i ld i ld2 lr lib 11lib2 1lib ld and Id2 1nk500 f1 0bj f2 0bj i ld i 1d2 lr lib 11ib2 1lib Linker Options 7 4 9 2 Name an Alternate Library Directory C DIR Environment Variable Operating System DOS UNIX An environment variable is a system symbol that you define and assign a string to The linker uses environment variables named C DIR and C54X C DIR to name alternate directories that contain object libraries The commands for assigning the environment variable are Operating System Enter DOS set C DIR pathname another pathname UNIX setenv C DIR pathname another pathname The pathnames are directories that contain object libraries Use the option on the command line or in a command file to tell the linker which libraries to search for In the example below assume that two archive libraries called r lib and lib2 lib reside in Id and ld2 directories The table below shows the directories that r lib and lib2 lib reside in how to set the environment variable and how to use both libraries during a link Select the row for your operating system Pathname Invocation Command Md and ld2 set C_DIR ld ld2 1nk500 f
182. bler to begin reading source statements from another file When the assembler finishes reading the source statements in the copy include file it resumes reading source statements from the current file immediately following the point at which the copy or include directive occurred The statements read from a copied file are printed in the listing file the statements read from an included file are not printed in the listing file The def directive identifies a symbol that is defined in the current module and that can be used by another module The assembler includes the symbol in the symbol table The global directive declares a symbol external so that it is available to other modules at link time For more information about global symbols see subsection 2 8 1 External Symbols on page 2 21 The global directive does double duty acting as a def for defined symbols and as a ref for undefined symbols The linker resolves an undefined global symbol only if it is used in the program The ref directive identifies a symbol that is used in the current module but defined in another module The assembler marks the symbol as an undefined external symbol and enters it in the object symbol table so that the linker can resolve its definition Assembler Directives 4 19 Conditional Assembly Directives 4 8 Conditional Assembly Directives Conditional assembly directives enable you to instruct the assembler to assemble certain sections
183. boot routine c intOO defined in boot asm to load and run initializing the C environment and branching to the main function in the applications code The text and cinit sections must be linked together as a single section in the linker command file The cinit section contains the initialization data and tables for all global or static C symbols that were declared with an initial value i e int x 2 5 Note that the linker handles the cinit section differently than the other sections When the linker encounters a cinit section specified as an output section in the link it automatically Sets the symbol cinit to point to the start of the included cinit section L Appends a single word to the end of the section This last word contains a zero that is used to mark the end of the initialization table However if cinit is included as an input section only the linker sets cinit to 1 indicating that no initialization tables were loaded Therefore the C boot routine c_int00 does not attempt to initialize any of the global or static C symbols When linking the cinit section into an output section other than cinit the linker does not perform the automatic functions listed above Therefore these func tions must be implemented explicitly within the linker command file The fol lowing example shows a linker command file that places text and cinit into a single output section named boot sec Hex Conversion Utility Examples
184. bout required labels The given directive requires a label but none is specified Action Correct the source by specifying the required label Assembler Error Messages D 7 Assembler Error Messages Labels are not allowed with this directive Standalone labels not permitted in structure union defs Description These are errors about invalid labels The given directive does not permit a label but one is specified Description Remove the invalid label Assembler Error Messages Local label number defined differently in each pass Local label number is multiply defined Local label number is not defined in this section Local labels can t be used with directives Description These are errors about the illegal use of local labels Action Correct the source per the error message text Use newblock to reuse local labels Bad term in expression Binary operator can t be applied Cannot resolve symbol in expression Difference between segment symbols not permitted Expression evaluation failed Illegal divide by zero Illegal remainder by zero Integer divide by zero Integer remainder by zero Offset expression must be integer value Operation cannot be performed on given operands Unable to compose expression Unary operator can t be applied Value of expression has changed due to jump expansion Well defined expression required Description These are errors about general expressions An illegal oper and combination was used or an a
185. commonly generated when a C program is compiled for debugging For example header h typedef struct define some structure members XYZ l l include header h f2s include header h When these files are compiled for debugging both f1 obj and f2 obj will have symbolic debugging entries to describe type XYZ For the final output file only one set of these entries is necessary The linker eliminates the duplicate entries automatically Use the b option if you want the linker to keep such duplicate entries Using the b option has the effect of the linker running faster and using less machine memory 7 4 3 C Language Options c and cr Options The c and cr options cause the linker to use linking conventions that are required by the C C compiler The c option tells the linker to use the ROM autoinitialization model O The cr option tells the linker to use the RAM autoinitialization model For more information about linking C C code see Section 7 17 Linking C C Code on page 7 72 and subsection 7 17 5 The c and cr Linker Options on page 7 75 Linker Options 7 4 A Define an Entry Point e global symbol Option The memory address at which a program begins executing is called the entry point When a loader loads a program into target memory the program counter must be initialized to the entry point the PC then points to the beginning of the program The li
186. contains the name of the output module and the entry point it may also contain up to three tables Atable showing the new memory configuration if any non default memory is specified Lj Atable showing the linked addresses of each output section and the input sections that make up the output sections Linker Options Atable showing each external symbol and its address This table has two columns the left column contains the symbols sorted by name and the right column contains the symbols sorted by address This example links file1 0bj and file2 obj and creates a map file called file map 1nk500 filel obj file2 0bj m file map Example 7 15 on page 7 78 shows an example of a map file 7 4 13 Name an Output Module o filename Option The linker creates an output module when no errors are encountered If you do not specify a filename for the output module the linker gives it the default name a out If you want to write the output module to a different file use the o option The syntax for the o option is o filename The filename is the new output module name This example links file1 obj and file2 obj and creates an output module named run out 1nk500 o run out filel obj file2 obj 7 4 14 Specify a Quiet Run q Option The q option suppresses the linker s banner when qis the first option on the command line or in a command file This option is useful for batch operation 7 4 15 Strip Symbolic Informa
187. ct code two charac ters per byte Figure 10 14 illustrates the Tektronix object format Figure 10 14 Extended Tektronix Object Format Checksum 21h 1 5 6 8 1 0 0 0 0 0 0 0 2 0 2 04 2 0 2 0 2 0 2 0 Block length 15hs21 r Object code 6 bytes Fd o 1 Header 815621810000000202020202020 character L Load address 10000000h Blocktype 6 Length of data load address 10 44 Hex Conversion Utility Error Messages 10 12 Hex Conversion Utility Error Messages section mapped to reserved memory message Description A section or a boot loader table is mapped into a reserved Action memory area listed in the processor memory map Correct the section or boot loader address Refer to the TMS320C54x DSP Reference Set for valid memory locations sections overlapping Description Two or more COFF section load addresses overlap or a boot Action table address overlaps another section This problem may be caused by an incorrect translation from load address to hex output file address that is performed by the hex conversion utility when memory width is less than data width See Section 10 4 Understanding Memory Widths on page 10 9 and Section 10 10 Controlling the ROM Device Address on page 10 35 unconfigured memory error Description This error could have one of two causes Action B The COFF file contains a section whose load address falls outside the memory range defin
188. ct directive The symbol corresponds to the name of the variable that you re reserving space for It can be referenced by any other section and can also be de clared as a global symbol with the global assembler direc tive size in words is an absolute expression The bss directive reserves size words in the bss sec tion _j The usect directive reserves size words in section name blocking flag is an optional parameter If you specify a value other than 0 for this parameter the assembler associates size words contiguously the allocated space will not cross a page boundary unless size is greater than a page in which case the object will start on a page boundary alignment flag is an optional parameter If you specify a value other than 0 for this parameter the section is aligned to a long word boundary section name tells the assembler which named section to reserve space in For more information about named sections see subsection 2 3 3 Named Sections on page 2 8 The text data and sect directives tell the assembler to stop assembling into the current section and begin assembling into the indicated section The bss and usect directives however do notend the current section and begin a new one they simply escape temporarily from the current section The bss and usect directives can appear anywhere in an initialized section without affecting its contents Uninitialized subsections can be created with th
189. ction doubleand Idouble calculate the single precision 32 bit IEEE floating point representation of one or more floating point values and store them in two consecutive words in the current section The double directive automatically aligns to the long word boundary long ulong and xlong place 32 bit values into two consecutive words in the current section The most significant word is stored first The long directive automatically aligns to a long word boundary and the xlong directive does not String and pstring place 8 bit characters from one or more character strings into the current section The string directive is similarto byte plac ing an 8 bit character in each consecutive word of the current section The pstring also has a width of 8 bits but packs two characters into a word For pstring the last word in a string is padded with null characters 0 if necessary Note These Directives in a struct endstruct Sequence The directives listed above do not initialize memory when they are part of a struct endstruct sequence rather they define a member s size For more information about the struct endstruct directives see Section 4 9 Assembly Time Symbol Directives on page 4 21 Figure 4 3 compares the byte int long xlong float xfloat word and String directives For this example assume that the following code has been assembled Assembler Directives 4 13 Directives
190. ction combines the const sections from file1 obj and file2 obj FF80h vectors bound at OFF80h The vectors section is composed of the intvec1 section from t1 obj and the intvec2 section from t2 obj 7 34 7 8 3 Allocation The SECTIONS Directive The linker assigns each output section two locations in target memory the location where the section will be loaded and the location where it will be run Usually these are the same and you can think of each section as having only a single address In any case the process of locating the output section in the target s memory and assigning its address es is called allocation For more information about using separate load and run allocation see Section 7 9 Specifying a Section s Runtime Adaress on page 7 44 If you do not tell the linker how a section is to be allocated it uses a default algorithm to allocate the section Generally the linker puts sections wherever they fit into configured memory You can override this default allocation for a section by defining it within a SECTIONS directive and providing instructions on how to allocate it You control allocation by specifying one or more allocation parameters Each parameter consists of a keyword an optional equal sign or greater than sign and a value optionally enclosed in parentheses If load and run allocation is separate all parameters following the keyword LOAD apply to load allocation and those foll
191. ctive Normally any reference to a symbol in a section refers to its runtime address However it may be necessary at runtime to refer to a load time address Specifically the code that copies a section from its load address to its run address must have access to the load address The label directive defines a special symbol that refers to the section s load address Thus whereas normal symbols are relocated with respect to the run address label symbols are relocated with respect to the load address For more information on the label directive see page 4 60 Example 7 6 shows the use of the label directive Linker Description 7 45 Specifying a Section s Runtime Address Example 7 6 Copying a Section From ROM to RAM 7 46 define a section to be copied from ROM to RAM Sect fir label fir src load address of section fir run address of section code here code for the section label fir end load address of section end Copy fir section from ROM into RAM text STM fir src AR1 get load address RPT fir_end fir src 1 MVDP AR1 fir copy address to program memory jump to section now in RAM CALL fir Linker Command File PA
192. ctive was encountered that requires a matching directive but the assembler could not find the matching directive Action Correct the source per the error message text Conditional nesting is too deep Loop count out of range Description These are errors about conditional assembly loops Condi tional block nesting cannot exceed 32 levels Action Correct the macro endmacro if elseif else endif or loop break endloop source Assembler Error Messages Bad use of access directive Matching struct directive is not present Matching union directive is not present Description These are errors about unmatched structure definition direc tives In a struct endstruct sequence a directive was encountered that requires a matching directive but the assembler could not find the matching directive Action Check the source for mismatched structure definition direc tives and correct Cannot apply bitwise NOT to floats Illegal struct union reference dot operator Missing structure union member or tag Section name is not an initialized section Structure or union tag symbol expected Structure or union tag symbol not found Description These are errors about an illegally used operator The opera tor specified was not legal for the given operands Action Correct the source per the error message text so that all required operands are declared Label missing Label required setsym requires a label Description These are errors a
193. ctives in Macros srs me cette en 11 5 2 Macro Local Variables a a de cette 11 5 3 Defining Labels When Invoking A Macro Common Object File Format 0 0c cece eee eee nnn nnn Contains supplemental technical data about the internal format and structure of COFF object files A COFF File Structure os A 1 1 Impact of Switching Operating Systems i A 2 File Header Structure sssssssssssesess tenet nent eens A 3 Optional File Header Format i A 4 Section Header Structure nD a nnl A 5 Structuring Relocation Information i A 6 Line Number Table Structure i A 7 Symbol Table Structure and Content i A 74 Special Symbols ne A 7 2 Symbol Name Format ss i a A a i ae A 7 3 String Table Structure uussssssselessssselslle ees A 7 4 Storage Classes enice osotu ies iaraa tenet nn A 7 5 Symbol Values eiii isasara aa eee n A 7 6 Section Number 0 Ala De En rsrsrs ner nni An AEREE A 8 Auxiliary Entries rn on ed nn Symbolic Debugging Directives ee Discusses symbolic debugging directives that the C compiler uses Hex Conversion Utility Examples eeseeeeeeee III IH C 1 Illustrates command file development for a variety of memory systems and situations C 1 Base Code for the Examples i C 2 Example 1 Building A Hex Command File for Two 8 Bit EPROMs C 3 Example 2 Avoiding Holes With Multiple Sections i C 4 Example 3 Generating a Boot Table i C 5 Example 4 Generat
194. ctor See Section 10 10 Controlling the ROM Device Address on page 10 35 for more information You must eliminate the holes between converted sections The sections can be made contiguous in one of two ways Specify a paddr value for each section listed in a SECTIONS directive This forces the hex conversion utility to use that specific address for the output file address field You must ensure that the section addresses do notoverlap Example C 5 a shows alinker command file forthis method The linker should be executed with this command file then the hex conversion utility should be executed with the set of commands shown in Example C 5 b Link the sections together into one output section for conversion Example C 6 a shows a linker command file for this method The linker should be executed with this command file then the hex conversion utility should be executed with the set of commands shown in Example C 6 b Example C 5 Method One for Avoiding Holes a Linker command file SPECIFY THE SPECIFY THE S Mi EMORY PAGE 0 DA SYSTEM MEMORY MAP RAM org EXT org SECTIONS ALLOCATION INTO MEMORY 0x1370 OxEB80 0x0080 length 0x1400 length ECTIONS secl load EXT PAGE 0 sec2 load EXT PAGE 0 Example 2 Avoiding Holes With Multiple Sections b Hex command file x test
195. d d commands verbose provides a file by file description of the creation of a new library from an old library and its constituent members names an archive library If you don t specify an extension for libname the archiver uses the default extension ib names individual member files that are associated with the library You must specify a complete filename including an extension if applicable It is possible but not desirable for a library to contain several members with the same name If you attempt to delete replace or extract a member and the library contains more than one member with the specified name then the archiver deletes replaces or extracts the first member with that name Archiver Description 6 5 Archiver Examples 6 4 Archiver Examples The following are some archiver examples If you want to create a library called function lib that contains the files sine obj cos obj and flt obj enter ar500 a function sine obj cos obj flt obj TMS320C54x Archiver Version x xx Copyright c 2001 Texas Instruments Incorporated gt new archive function 1lib gt building archive function lib You can print a table of contents of function lib with the t option ar500 t function TMS320C54x Archiver Version X xx Copyright c 2001 Texas Instruments Incorporated FILE NAME SIZE DATE sine obj 248 Mon Nov 19 01 25 44 2001 cos obj 248 Mon Nov 19 01 25 44 2001
196. d and write all types of COFF files By default the linker creates COFF2 files Use the v linker option to specify a different format The linker supports COFFO and COFF1 files for older versions of the assembler and C compiler only 2 2 2 2 Sections Sections The smallest unit of an object file is called a section A section is a block of code or data that will ultimately occupy contiguous space in the memory map Each section of an object file is separate and distinct COFF object files always con tain three default sections text section usually contains executable code data section usually contains initialized data bss section usually reserves space for uninitialized variables In addition the assembler and linker allow you to create name and link named sections that are used like the data text and bss sections There are two basic types of sections initialized sections contain data or code The text and data sections are initialized named sections created with the sect assembler directive are also initialized uninitialized sections reserve space for uninitialized data The bss sec tion is uninitialized named sections created with the usect assembler directive are also uninitial ized Several assembler directives allow you to associate various portions of code and data with the appropriate sections The assembler builds these sections during the assembly process creating an object file organized as sh
197. d directive to initialize several words a label would point to the first word In the following example the label Start has the value 40h 9 000000 Assume some other code was assembled 10 000040000A Start word 0Ah 3 7 000041 0003 000042 0007 A label on a line by itself is a valid statement The label assigns the current value of the section program counter to the label this is equivalent to the fol lowing directive statement label set S provides the current value of the SPC When a label appears on a line by itself it is assigned to the address of the instruction on the next line the SPC is not incremented 3 000043 Here 4 000043 0003 word 3 3 5 3 Mnemonic Instruction Fields In mnemonic assembly the label field is followed by the mnemonic and oper and fields These fields are described in the next two sections 3 5 3 1 Mnemonic Field 3 12 The mnemonic field follows the label field The mnemonic field must not start in column 1 if it does it will be interpreted as a label The mnemonic field can contain one of the following opcodes Machine instruction mnemonic such as ABS MPYU STH Assembler directive such as data list set Lj Macro directive such as macro var mexit Macro call 3 5 3 2 Operand Field Source Statement Format The operand field is a list of operands that follow the mnemonic field An operand can be a constant see Section 3 6 Constants on page 3 15
198. d in the current module the global or def directive declares that the symbol and its definition can be used externally by other modules These types of references are resolved at link time This example shows four files file1 Ist and file3 Ist are equivalent Both files define the symbol Init and make it available to other modules both files use the external symbols x y and z file1 Ist uses the global directive to identify these global symbols file3 Ist uses ref and def to identify the symbols file2 Ist and file4 Ist are equivalent Both files define the symbols x y and z and make them available to other modules both files use the external symbol Init file2 Ist uses the global directive to identify these global symbols file4 Ist uses ref and def to identify the symbols Assembler Directives 4 51 global def ref Identify Global Symbols file1 Ist I Global symbol defined in this file 2 global INIT 3 Global symbols defined in file2 1st 4 global X Y Z 5 000000 INIT 6 000000 F000 ADD 56h A 000001 0056 7 000002 0000 word X 8 D 9 10 11 end file2 Ist d Global symbols defined in this file 2 global X Y Z 3 Global symbol defined in filel lst 4 global INIT 5 0001 X set 1 6 0002 Y set 2 7 0003 Z Set 3 8 000000 0000 word INIT 9 i 10 11 12 end file3 Ist 1 Global symbol defined in this file 2 def INIT 3 Global symbols defined in file4 1st 4 ref X Y Z 5 0000
199. data raw data lt named gt section raw data text relocation information data i relocation relocation information information lt named gt section relocation information text line numbers data line number line numbers entries lt named gt section line numbers symbol table string table Common Object File Format A 3 COFF File Structure A 1 1 A 4 Impact of Switching Operating Systems The C54x COFF files are recognized by all operating system versions of the development tools When you switch from one operating system to another only the file header information in the COFF files needs to be byte swapped The raw data in the COFF files does not need any changes The C54x development tools can detect the difference in the file headers and automatically compensate for it This is true if using only C54x development tools To tell the difference between COFF files you can look at the magic number in the optional file header Bytes 0 and 1 contain the magic number For the SunOS or HP UX operating systems the magic number is 108h For the DOS operating system the magic number is 801h File Header Structure A 2 File Header Structure The file header contains 22 bytes of information that describe the general format of an object file Table A 1 shows the structure of the COFF file header Table A 1 File Header Contents Byte Number Type Description 0 1
200. depends on 10 11 format used Invoking the Hex Conversion Utility Table 10 1 Hex Conversion Utility Options Continued d Output formats The output formats specify the format of the output file Option a Description Page Select ASCII Hex 10 40 Select Intel Select Motorola S1 Select Motorola S2 default 10 42 Select Motorola S3 10 42 Select Tl Tagged Select Tektronix 10 44 e Boot loader options for all C54x devices The boot loader options for all C54x devices control how the hex conversion utility builds the boot table Option boot bootorg PARALLEL bootorg SERIAL bootorg value bootpage value e value Description Page Convert all sections into bootable form use instead 10 30 of a SECTIONS directive Specify the source of the boot loader table as the 10 29 parallel port Specify the source of the boot loader table as the 10 29 serial port Specify the source address of the boot loader table 10 30 Specify the target page number of the boot loader 10 30 table Specify the entry point at which to begin execution 10 29 after boot loading The value can be an address or a global symbol Hex Conversion Utility Description 10 5 Invoking the Hex Conversion Utility Table 10 1 Hex Conversion Utility Options Continued 10 6 f Boot loader options for the C54x LP devices only Option bootorg WARM or warm bootorg COMM spc value spc
201. directive C54X A DIR environment variable C54X C DIR environment variable 7 13 to to A 13 Index 4 char directive character constant string Cinit section 7 73 7sjto 7 74 tables cinit symbol 7 73 to clink directive COFF array limitation auxiliary entries conversion to eh format 10 1 to 10 48 See also hex conversion utility default allocation 7 58 defined file structure to A 4 file types 2 2 headers file optional section to in the development flow 7 3 10 2 initialized sections 2 7 line number entries linker 7 1 loading a program object file example relocation to 2 18 runtime relocation Sections allocation assembler described special types uninitialized storage classes symbol table structure and content A 14 to symbol values symbolic debugging symbols to 2 technical details type entry uninitialized sections 2 5 to command file defined hex conversion utility 10 7 to 10 8 linker constants in described to 7 24 examples to invoking reserved words comments defined extending past page width field pia in a linker command file 7 22 in assembly language source code 3 14 in macros 5 19 common object file format See COFF conditional blocks assembly directives listing of false conditional blocks 4 46 conditional processing assembly directives in macros b 15 to 5 16 maximum nesting levels defined expressions 3 27 configur
202. dly assemble a block of code The loop directive begins a repeatable block of code The optional expression evaluates to the loop count the number of times to repeat the assembly of the code contained in the loop If there is no expression the loop count defaults to 1024 unless the assembler first encounters a break directive with an ex pression that is true nonzero or omitted The break directive is optional along with its expression When the expres sion is false 0 the loop continues When the expression is true nonzero or omitted the assembler breaks the loop and assembles the code after the endloop directive The endloop directive terminates a repeatable block of code it executes when the break directive is true nonzero or when number of loops performed equals the loop count given by loop This example illustrates how these directives can be used with the eval directive 1 eval 0 x 2 COEF loop 3 word x 100 4 eval xl x 5 break x 6 6 endloop 000000 0000 word 0 100 eval Qs X break 1 6 000001 0064 word 1 100 eval 1 1 x break 226 000002 00C8 word 2 100 eval 241 Xx break 326 000003 012C word 3 100 eval 3 1 x break 4 6 000004 0190 word 4 100 eval 4 1 x break 526 000005 01F4 word 5 100 eval 54 1 x break 6 6 Define Macro macro Syntax macname macro parameter parameter model statements or macro directives endm Description The macro direct
203. dular programming Object files contain separate blocks called sections of code and data that you can load into C54x memory spaces You can program the C54x more efficiently if you have a basic understanding of COFF Chapter 2 Introduction to Common Object File Format discusses this object format in detail Topic Page 1 1 Software Development Tools Overview s s 1 2 1 2 Tools Descriptions 55 9 xem RES naar net ta Software Development Tools Overview 1 1 Software Development Tools Overview Figure 1 1 illustrates the C54x software development flow The shaded portion of the figure highlights the most common path of software development the other portions are optional Figure 1 1 TMS320C54x Software Development Flow C Source files Macro Source files C compiler Assembly i Assembler pores source Maco library i Assembler 5 Library build utility CE Library of object files Runtime support library Linker Executable COFF file Hex conversion utility EPROM programmer 1 2 Tools Descriptions 1 2 Tools Descriptions The following list describes the tools that are shown in Figure 1 1 m The C C compiler translates C C source code into C54x assembly language source code The compiler package includes the library build utility with which
204. e ismember a b 0 if string a is not defined in the symbol table top member of list b is assigned to string a 0 if bis a null string iscons a 1 if string ais a binary constant 2 if string a is an octal constant 3 if string a is a hexadecimal constant 4 if string a is a character constant 5 if string a is a decimal constant isname a 1 if string a is a valid symbol name 0 if string a is not a valid symbol name isreg a t 1 if string ais a valid predefined register name 0 if string ais not a valid predefined register name structsz a size of structure represented by structure tag a structacc a reference point of structure represented by structure tag a t For more information about predefined register names see Section 3 8 Symbols on page 3 19 Example 5 5 shows built in substitution symbol functions Example 5 5 Using Built In Substitution Symbol Functions asg label ADDR ADDR label UE Ssymemp ADDR label 0 evaluates to true SUB ADDR A endif asg OS yy p Aust list x y z SLf Sismember ADDR list addr x list y z SUB ADDR A sub x endif Macro Language 5 9 Macro Parameters Substitution Symbols 5 3 3 Recursive Substitution Symbols Example 5 6 Recursive Substitution When the assembler encounters a substitution symbol it attempts to substitute the corresponding character string If that string is also a substitution symbol the assembler performs substitu
205. e order Option Applies LI This option applies only when you use a memory width with a value less than 16 Otherwise order is ignored This option does not affect the way memory words are split into output files Think of the files as a set the set contains a least significant file and a most significant file but there is no ordering over the set When you list filenames for a set of files you alwayslistthe least significant first regard less of the order option Figure 10 6 demonstrates how order affects the conversion process This figure and the previous figure Figure 10 4 explain the condition of the data in the hex conversion utility output files Figure 10 6 Varying the Word Order Source file word OAABBh word 01122h Target width 16 fixed OAABBh 0 1L112 2 m Memory widths variable memwidth 8 memwidth 8 order LS default order MS Hex Conversion Utility Description 10 15 The ROMS Directive 10 5 The ROMS Directive 10 16 The ROMS directive specifies the physical memory configuration of your system as a list of address range parameters Each address range produces one set of files containing the hex conversion utility output data that corresponds to that address range Each file can be used to program one single ROM device If you do notuse a ROMS directive the utility defines a default memory config uration that includes two address spac
206. e usect directive The assem bler treats uninitialized subsections in the same manner as uninitialized sections See subsection 2 3 4 Subsections on page 2 9 for more informa tion on creating subsections How the Assembler Handles Sections 2 3 2 Initialized Sections Initialized sections contain executable code or initialized data The contents of these sections are stored in the object file and placed in processor memory when the program is loaded Each initialized section is independently relocat able and may reference symbols that are defined in other sections The linker automatically resolves these section relative references Three directives tell the assembler to place code or data into a section The syntaxes for these directives are text value data value sect section name value When the assembler encounters one of these directives it stops assembling into the current section acting as an implied end current section command It then assembles subsequent code into the designated section until itencoun ters another text data or sect directive The value if present specifies the starting value of the section program counter The starting value of the section program counter can be specified only once it must be done the first time the directive for that section is encountered By default the SPC starts at 0 Sections are built through an iterative process For example when the assem bler
207. e appropriate SPC If you resume assembling into a section the assembler remembers the appropriate SPC s previous val ue and continues incrementing the SPC at that point The assembler treats each section as if it began at address 0 the linker relocates each section according to its final location in the memory map For more information see Section 2 5 Helocation on page 2 16 Introduction to Common Object File Format 2 9 How the Assembler Handles Sections 2 3 6 An Example That Uses Sections Directives 2 10 Example 2 1 shows how you can build COFF sections incrementally using the sections directives to swap back and forth between the different sections You can use sections directives to begin assembling into a section for the first time or to continue assembling into a section that already contains code In the latter case the assembler simply appends the new code to the code that is already in the section The format in Example 2 1 is a listing file Example 2 1 shows how the SPCs are modified during assembly A line in a listing file has four fields Field 1 contains the source code line counter Field 2 contains the section program counter Field 3 contains the object code Field 4 contains the original source statement How the Assembler Handles Sections Example 2 1 Using Sections Directives 2
208. e in words is an expression that defines the number of words that are reserved in section name blocking flag is an optional parameter If specified and nonzero the flag means that this section will be blocked Blocking is an ad dress mechanism similar to alignment but weaker It means a section is guaranteed to not cross a page bound ary 128 words if itis smaller than a page and to start on a page boundary if it is larger than a page This blocking applies to the section not to the object declared with this instance of the usect directive alignment flag is an optional parameter This flag causes the assembler to allocate size on long word boundaries ee ee Note Specifying an Alignment Flag Only To specify an alignment flag without a blocking flag you must insert two commas before the alignment flag as shown in the syntax LLLLLLLL Other sections directives text data and sect end the current section and tellthe assemblerto begin assembling into another section The usect and the bss directives however do not affect the current section The assembler assembles the usect and the bss directives and then resumes assembling into the current section Variables that can be located contiguously in memory can be defined in the same specified section to do so repeat the usect directive with the same sec tion name Asse
209. e ke x x f Linker Description 7 77 Linker Example Invoke the linker with the following command lnk500 demo cmd This creates the map file shown in Example 7 15 and an output file called demo out that can be run on a TMS320C54x Example 7 15 Output Map File demo map OUTPUT FILE NAME demo out ENTRY POINT SYMBOL 0 EMORY CONFIGURATION name origin length used attributes fill PAGE 0 RAM PG 00000080 000006 80 00000002 RWIX ROM 0000c000 000003f80 00000011 RWIX PAGE 1 ONCHIP 00000080 000000f7 00000105 RWIX EXT 00001000 200000efff 00000000 RWIX SECTION ALLOCATION MAP output attributes section page origin length input sections text 0 0000c000 00000011 0000c000 00000008 demo obj text 0000c008 00000004 fft obj text 0000c00c 00000005 tables obj text var defs 1 00000080 00000002 00000080 00000002 demo obj var defs data 1 00000082 00000100 00000082 00000001 tables obj data 00000083 00000004 fft obj data 00000087 000000fb HOLE fill 7alc 00000182 00000000 demo obj data bss 0 00000080 00000002 00000080 00000002 demo obj bss fill ffff 00000082 00000000 tables obj bss 00000082 00000000 fft obj bss Xy 1 00000182 00000003 UNINITIALIZED 00000182 00000003 demo obj xy GLOBAL SYMBOLS address name address name 00000080 bss 00000080 bss 00000082 data 00000082 data 0000c000 text 00000082 TEMP 0000c002 ARRAY
210. e packed starting at the most significant part of the word moving toward the least significant part as more fields are added If the assembler encounters a field size that does not fit into the current word it writes out the word increments the SPC and begins packing fields into the next word You can use the align directive with an operand of 1 to force the next field directive to begin packing into a new word If you use a label it points to the word that contains the specified field When you use field in a struct endstruct sequence field defines a member s size it does not initialize memory For more information about struct endstruct see Section 4 9 Assembly Time Symbol Directives on page 4 21 Assembler Directives 4 47 field nitialize Field Example This example shows how fields are packed into a word Notice that the SPC does not change until a word is filled and the next word is begun 1 2 EE Initialize a 14 bit field 3 ck ck 0k 0k Ck ck Ck kk ck Ck ck kk kk kk xk ke kx ko ko ko ko ck okok 4 000000 2AF0 field OABCh 14 5 6 7 EE Initialize a 5 bit field Wo 8 in a new word 9 3 ke e he ce e ce e ce e ee oe e cde ee ecce oe
211. e value arr value bkr value tcsr value trta value swwsr value bscr value Description Specify the source of the boot loader table as the table currently in memory Specify the source of the boot loader table as the communications port Set the serial port control register value Set the serial port control extension register value Set the ABU receive address register value Set the ABU transmit buffer size register value Set the TDM serial port channel select register value Set the TDM serial port receive transmit address register value Set the Software Wait State Reg value for PARALLEL WARM boot mode Set the Bank Switch Control Reg value for PARALLEL WARM boot mode gt d Lle oll o T v o F DI IN oO 10 eo m m m m m 2 N 2 N T m Command File 10 3 Command File A command file is useful if you plan to invoke the utility more than once with the same input files and options It is also useful if you want to use the ROMS and SECTIONS hex conversion utility directives to customize the conversion process Command files are ASCII files that contain one or more of the following Options and filenames These are specified in a command file in exactly the same manner as on the command line ROMS directive The ROMS directive defines the physical memory con figuration of your system as a list of address range parameters
212. e was not generated by the C compiler you should add the c mode directive to your assembly files Assembler Directives 4 35 copy include Read Source File Syntax Description copy filename include filename The copy and include directives tell the assembler to read source state ments from a different file The statements that are assembled from a copy file are printed in the assembly listing The statements that are assembled from an included file are not printed in the assembly listing regardless of the num ber of list nolist directives assembled The assembler 1 Stops assembling statements in the current source file 2 Assembles the statements in the copied included file 3 Resumes assembling statements in the main source file starting with the statement that follows the copy or include directive The filename is a required parameter that names a source file It may be en closed in double quotes and must follow operating system conventions You can specify a full pathname for example c dsp file1 asm If you do not speci fy a full pathname the assembler searches for the file in 1 The directory that contains the current source file 2 Any directories named with the i assembler option 3 Any directories specified by the environment variable A DIR For more information about the i option and A DIR see Section 3 4 Naming Alternate Directories for Assembler Input on page 3 8 The co
213. eader Flags Bytes 18 and 19 eee eee ne ae A 3 Optional File Header Contents 0 A 4 Section Header Contents for COFF1 Files es A 5 Section Header Contents for COFF2 Files es A 6 Section Header Flags 0 A 7 Relocation Entry Contents adda Lia cece Te eee tenet eens A 8 Relocation Types Bytes 8 and 9 0 A 9 Line Number Entry Format ss A 10 Symbol Table Entry Contents i A 11 Special Symbols in the Symbol Table i A 12 Symbol Storage Classes icis inini cuiii raskir eens A 13 Special Symbols and Their Storage Classes i A 14 Symbol Values and Storage Classes i A 15 Section Numbers 00 era d gh kr ERE X Ra od e UE seem A 16 BasicTypes A 17 Derived Types 222 adsl ROI rarr An aT e e ERRIDSaXDPRANId E A 18 Auxiliary Symbol Table Entries Format i A 19 Filename Format for Auxiliary Table Entries i xvi Contents A 20 Section Format for Auxiliary Table Entries i A 21 Tag Name Format for Auxiliary Table Entries i A 22 End of Structure Format for Auxiliary Table Entries A 23 Function Format for Auxiliary Table Entries A 24 Array Format for Auxiliary Table Entries i A 25 End of Blocks Functions Format for Auxiliary Table Entries sess A 26 Beginning of Blocks Functions Format for Auxiliary Table Entries A 27 Structure Union and Enumeration Names Format for Auxiliary Table Entries Contents xvii Examples 2 1 Using Sections Directives 0 2 2 Code That Generates Relocation
214. earch the library and use the members that are called as macros by the source file You can also use the archiver to collect a group of object files into an object library The linker will include in the library the mem bers that resolve external references during the link Topic Page 6 1 Archiver Overview ss sm ne nn ee i 2 6 2 Archiver Development Flow ss 6 3 6 3 Inyoking the Archiver me ma e a teens 6A mArchivenExampies mene 6 1 Archiver Overview 6 1 Archiver Overview The TMS320C54x archiver lets you combine several individual files into a single file called an archive or a library Each file within the archive is called a member Once you have created an archive you can use the archiver to add delete or extract members You can build libraries from any type of files Both the assembler and the linker accept archive libraries as input the assembler can use libraries that contain individual source files and the linker can use libraries that contain individual object files One of the most useful applications of the archiver is building libraries of object modules For example you can write several arithmetic routines assemble them and use the archiver to collect the object files into a single logical group You can then specify the object library as linker input The linker will search the library and include members that resolve external references You can also use the archiver to build macro librari
215. ecified by the linker and contained in the COFF file By using the e option with the hex conversion utility you can set the entry point to a different address For example if you want your program to start running at address 0123h after loading specify e 0123h on the command line or in a command file You can determine the e address by looking at the map file that the linker generates m 7 Note Valid Entry Points The value can be a constant or it can be a symbol that is externally defined for example with a global in the assembly source Building a Table for an On Chip Boot Loader When you use the e option the utility builds a dummy block of length 1 and data value 0 that loads atthe specified address Your blocks follow this dummy block Since the dummy block is loaded first the dummy value of 0 is over written by the subsequent blocks Then the boot loader jumps to the e option address after the boot load is completed When using the bootorg WARM option the e option sets the address of where the boot table is loaded in ROM 10 9 6 Using the C54x Boot Loader This subsection explains and gives an example on using the hex conversion utility with the boot loader for C54x devices The C54x boot loader has several different modes You can select these modes by using the bootorg and memwidth options Mode bootorg Setting memwidth Setting 8 bit parallel MO bootorg PARA
216. ecify alignment with the SECTIONS linker directive allocation A process in which the linker calculates the final memory addresses of output sections archive library A collection of individual files that have been grouped into a single file archiver A software program that allows you to collect several individual files into a single file called an archive library The archiver also allows you to delete extract or replace members of the archive library as well as to add new members ASCII American Standard Code for Information Exchange A standard computer code for representing and exchanging alphanumeric informa tion assembler A software program that creates a machine language program from a source file that contains assembly language instructions direc tives and macro directives The assembler substitutes absolute opera tion codes for symbolic operation codes and absolute or relocatable addresses for symbolic addresses assembly time constant A symbol that is assigned a constant value with the set directive F 1 Glossary assignment statement A statement that assigns a value to a variable autoinitialization The process of initializing global C variables contained in the cinit section before beginning program execution auxiliary entry The extra entry that a symbol may have in the symbol table and that contains additional information about the symbol whether it is a filename a section name a function
217. eclare this label as global Normal labels must be unique they can be declared only once and they can be used as constants in the operand field Local labels however can be undefined and defined again or automatically generated Local labels cannot be defined by directives A local label can be undefined or reset in one of four ways L By using the newblock directive Lj By changing sections using a sect text or data directive DD By entering an include file specifying the include or copy directive LJ By leaving an include file reaching the end of an included file Example 3 1 demonstrates the nform of local labels This example assumes that symbols ADDRA ADDRB ADDRC have been defined previously Example 3 1 n Local Labels a Code that uses a local label legally Labell LD ADDRA A Load Address A to Accumulator A SUB ADDRB A Subtract Address B BC 1 ALT If less than zero branch to 1 LD ADDRB A otherwise load ADDRB to A B 2 and branch to 2 1 LD ADDRA A 1 load ADDRA to Accumulator A 2 ADD ADDRC A 2 add ADDRC newblock Undefine 1 so it can be used again BC 1 ALT If less than zero branch to 1 STL A ADDRC Store ACC low in ADDRC 1 NOP Symbols b Code that uses a local label illegally Labell LD ADDRA A Load Address A to Accumulator A SUB ADDRB A Subtract Address B BC 1 ALT If less than zero branch to 1 LD
218. ecord types Record Type Description 00 Data record 01 End of file record 04 Extended linear address record Record type 00 the data record begins with a colon andis followed by the byte count the address of the first data byte the record type 00 and the checksum Note that the address is the least significant 16 bits of a 32 bit address this value is concatenated with the value from the most recent 04 extended linear address record to create a full 32 bit address The checksum is the 2s complement in binary form of the preceding bytes in the record including byte count address and data bytes Record type 01 the end of file record also begins with a colon followed by the byte count the address the record type 01 and the checksum Record type 04 the extended linear address record specifies the upper 16 address bits It begins with a colon followed by the byte count a dummy address of Oh the record type 04 the most significant 16 bits of the address and the checksum The subsequent address fields in the data records contain the least significant bits of the address Figure 10 11 illustrates the Intel hexadecimal object format Intel Hex Object Format Extended linear address record 1 020000040001F9 2000200010001100120013001400150016001700180019001A001B001C001D001E001F0048 Data 2000400000000100020003000400050006000700080009000A000B000C000D000E000F0028 records see OUTRO TOO Lag
219. ect directives do not end the current section or begin new sections they reserve the specified amount of space and then the assembler resumes assembling code or data into the current section Assembler Directives 4 9 Directives That Define Sections Example 4 1 Sections Directives 000001 000A 13 000002 000B 000003 000C 26 000004 000D 000005 000E 000007 0008 1 2 Start assembling into the text section 3 4 000000 text 5 000000 0001 word 1 2 000001 0002 6 000002 0003 word 3 4 000003 0004 7 8 9 Start assembling into the data section T0 ck ck ck 0k ck ck ck ck ck ck ck 0k ck kk ck Ck ck ck 0k ck Ck ck ck ck ck ck 0k ck Ck ck ck ck ck o ckock kk ck ko Sk Sk Sk KKK ko ko ko 11 000000 data 12 000000 0009 word 9 10 word 11 12 4 5 ck ck ck ck ck ck 0k ck KK ck 0k ck kk ck kk ck 0k ck Cc ck Ck ck ck 0k ck ck ck ck koc kk ck kk kk ck KKK ko
220. ecting immediate value operand op Not expecting indirect operand op Offset Addressing modes not legal for MMR addressing Operand must be auxiliary register or SP Operand must be auxiliary register Operand must be T Register must be ARn or SP Single character operand expected String constant or substitution symbol expected String operand expected Structure Union tag symbol expected Substitution symbol operand expected The accumulator operands must be different The operands must be SP Description These errors are about illegal operands The instruction parameter or other operand specified was not legal for this syntax Action Correct the source per the error message text Assembler Error Messages D 5 Assembler Error Messages D 6 Missing field value operand Missing operand s Operand missing Tag identification operand required Tag symbol identifier required Description These are errors about missing operands a required oper and is not supplied Action Correct the source so that all required operands are declared break must occur within a loop Conditional assembly mismatch Matching endloop missing No matching if specified No matching endif specified No matching endloop specified No matching if specified No matching loop specified Open block s inside macro Unmatched endloop directive Unmatched if directive Description These are errors about unmatched conditional assembly directives A dire
221. ections i 7 15 2 Creating Holes se a cece eee nee ena NIS Filling Holes sees open dera 7 15 4 Explicit Initialization of Uninitialized Sections i 7 16 Partial Incremental Linking ses 7 17 Linking C C Code ssusssssssssssess ss hs 7 17 1 Runtime Initialization sn 7 17 2 Object Libraries and Runtime Support i 7 17 3 Setting the Size of the Stack and Heap Sections i 7 17 4 Autoinitialization ROM and RAM Models i 7 17 5 The c and cr Linker Options 0 1 18 Linker Example epa EE ES RTEISR SS EISE PRPE S EET Absolute Lister Description ssseeeeeeee III IH Explains how to invoke the absolute lister to obtain a listing of the absolute addresses of an object file 8 1 Producing an Absolute Listing 8 2 Invoking the Absolute Lister s serrrersrirrurnti kine AAD e AN RE EAE N A 8 3 Absolute Lister Example i Cross Reference Lister Description csssseeses nnn Explains how to invoke the cross reference lister to obtain a listing of symbols their definitions and their references in the linked source files 9 1 Producing a Cross Reference Listing 9 2 Invoking the Cross Reference Lister 9 3 Cross Reference Listing Example i Hex Conversion Utility Description leeeeeeeeee Explains how to invoke the hex utility to convert a COFF object file into one of several standard hexadecimal formats suitable for loading into an EPROM programmer 10 1 Hex Conversion Utility Dev
222. ed starting with 0 If there is no ROMS directive or only one range the utility omits this character c The file number in the set of files for the range starting with 0 for the least significant file For example assume coff out is for a 16 bit target processor and you are creating Intel format output With no output filenames specified the utility produces two output files named coff i00 and coff i01 If you include the following ROMS directive when you invoke the hex conversion utility you would have two output files ROMS rangel o 1000h 1 1000h range2 o 2000h 1 1000h These Output Files Contain This Data coff i00 1000h through 1FFFh coff i10 2000h through 2FFFh Hex Conversion Utility Description 10 25 Image Mode and the fill Option 10 8 Image Mode and the fill Option This section points out the advantages of operating in image mode and describes how to produce output files with a precise continuous image of a target memory range 10 8 1 The image Option 10 26 With the image option the utility generates a memory image by completely filling all of the mapped ranges specified in the ROMS directive A COFF file consists of blocks of memory sections with assigned memory locations Typically all sections are not adjacent there are gaps between sec tions in the address space for which there is no data When such a file is con verted withoutthe use of image mode the hex conversion utilit
223. ed EOF end of file Description There is a syntax error in the linker command file undefined symbol first referenced in file Description Either a referenced symbolis not defined or the r option was not used Unless the r option is used the linker requires that all referenced symbols be defined This condition prevents the creation of an executable output file Action Link using the r option or define the symbol Linker Error Messages E 15 Linker Error Messages E 16 undefined symbol in expression Description An assignment statement contains an undefined symbol unrecognized option Action Check the list of valid options zero or missing length for memory area Description A memory range defined with the MEMORY directive did not have a nonzero length Appendix F Glossary absolute address An address that is permanently assigned to a TMS320C54x memory location absolute lister A debugging tool that accepts linked files as input and creates abs files as output These abs files can be assembled to pro duce a listing that shows the absolute addresses of object code Without the tool an absolute listing can be prepared with the use of many manual operations algebraic An instruction that the assembler translates into machine code alignment A process in which the linker places an output section at an address that falls on an n bit boundary where nis a power of 2 You can sp
224. ed in the ROMS directive B The boot loader table address is not within the memory range defined by the ROMS directive Correct the ROM range as defined by the ROMS directive to cover the memory range as needed or modify the section load address or boot loader table address Remember that if the ROMS directive is not used the memory range defaults to the entire processor address space For this reason removing the ROMS directive could also be a workaround Hex Conversion Utility Description 10 45 Chapter 11 Mnemonic to Algebraic Translator Description The TMS320C54x mnemonic to algebraic translator utility converts assembly code written in the mnemonic instruction set to code written in the algebraic instruction set Topic Page 11 1 Translator Overview eo oa eee EE 1 2 11 2 Translator Development Flow ss vi 11 3 11 8 Invoking the Translator se se sn nas ne se A a a aE 11 4 Translation Modes 0 ee rere a e Ieyn enn 11 5 11 5 How the Translator Works With Macros 11 8 11 1 Translator Overview 11 1 Translator Overview The TMS320C54x mnemonic to algebraic translator utility converts mnemonic assembly instructions into algebraic assembly instructions Mnemonic instructions usually consist of a keyword and operands Algebraic instructions usually consist of operands and operators Algebraic instructions resemble higher level programming language instructions The tr
225. ed memory defined described const 7 34 constant assembly time 4 81 binary integers character 3 16 decimal integers 3 16 defined copy directive copy file copy directive hc assembler option 8 5 i option COPY section cr linker option Index cross reference lister creating the cross reference listing example in the development flow invoking 9 3 options symbol attributes cross reference listing assembler option defined described producing with the option directive 4 18 4 76 producing with cross reference lister 9 1 to 9 6 d archiver command assembler option 3 5 data directive data memory data section defined symbols decimal integer constants def directive identifying external symbols 2 21 default allocation fill value for holes memory allocation MEMORY configuration MEMORY model 7 27 section See COFF sections SECTIONS configuration development flow tools directives See also assembler directives defined linker MEMORY to 7 31 SECTIONS P 13 32 to symbolic debugging B 3 to B 1 directory search algorithm assembler 3 8 linker 7 13 double directive Index 5 Index drlist directive 4 171 4 41 error messages use in macros displayed by assembler D 1 to D 18 drnolist directive 4 17 displayed by linker E 1 to same effect with option directive generating use in macros EE hex conversion utility 1
226. efix a archiver command 6 4 assembler option 8 5 hex conversion utility option linker option A DIR environment variable abs500 command See absolute lister invoking absolute address defined absolute lister creating the absolute listing file defined described development flow example invoking options absolute listing a assembler option producing absolute output module producing relocatable Index algebraic defined F 1 source file translation from mnemonic 11 1 to 11 10 algebraic directive align directive 4 15 compatibility with C1x C2x C2xx C5x alignment 4 15 to 4 16 4 27 defined linker allocation alignment binding blocking described 2 3 GROUP memory default sections 7 35 to 7 43 UNION alternate directories linker 7 14 naming with i option naming with A_DIR naming with directives to 3 10 ar linker option ar500 command archive library allocating individual members 7 43 alternate directory back referencing defined exhaustively reading macros 4 68 object 7 25 to 7 26 types of files Index 1 Index archiver 1 3 commands defined examples 6 6 in the development flow invoking options overview arithmetic operators 3 26 arr hex conversion utility option 10 29 array definitions A 26 COFF limitation ASCII Hex eT format 10 40 asm500 command assembler built in functions character strings 3 18 co
227. eger Long integer Unsigned short integer Unsigned short integer Unsigned short integer Character Character Description 8 character section name padded with nulls Section s physical address Section s virtual address Section size in words File pointer to raw data File pointer to relocation entries File pointer to line number entries Number of relocation entries Number of line number entries Flags see Table A 6 Reserved Memory page number Table A 5 Section Header Contents for COFF2 Files Byte 0 7 8 11 12 15 16 19 20 23 24 27 28 31 32 35 36 39 40 43 44 45 46 47 Type Character Long integer Long integer Long integer Long integer Long integer Long integer Unsigned long Unsigned long Unsigned long Short Unsigned short Description 8 character section name padded with nulls Section s physical address Section s virtual address Section size in words File pointer to raw data File pointer to relocation entries File pointer to line number entries Number of relocation entries Number of line number entries Flags see Table A 6 Reserved Memory page number Common Object File Format A 7 Section Header Structure Table A 6 lists the flags that can appear in the section header The flags can be combined For example if the flag s word is set to 024h both STYP GROUP and STYP TEXT are set Table A 6 Section Header Flags Mnemonic Flag Description STYP REG 0000h Regular section all
228. elocated at load time Linking a file that will be relinked with other files is called partial linking For more information see Section 7 18 Linker Example on page 7 76 J Producing an Executable Relocatable Output Module ar If you invoke the linker with both the a and r options the linker produces an executable relocatable object module The output file contains the special linker symbols an optional header and all resolved symbol references however the relocation information is retained The following example links file1 obj and file2 obj and creates an executable relocatable output module called xr out lnk500 ar filel obj file2 0bj o xr out You can string the options together Ink500 ar or enter them separately Ink500 a r J Relocating or Relinking an Absolute Output Module The linker issues a warning message but continues executing when it encounters a file that contains no relocation or symbol table information Relinking an absolute file can be successful only if each input file contains no information that needs to be relocated that is each file has no unresolved references and is bound to the same virtual address that it was bound to when the linker created it Linker Description 7 9 Linker Options 7 4 2 Disable Merge of Symbolic Debugging Information b Option By default the linker eliminates duplicate entries of symbolic debugging information Such duplicate information is
229. elopment Flow es 10 2 Invoking the Hex Conversion Utility lisse 10 3 Command File uua De ra ee 10 3 14 Examples of Command Files 0 0 0 0 0 i tenes 10 4 Understanding Memory Widths i 10 4 1 Target Width es siii Sa ete es Contents Xi Contents 1042 Data Width cos peset ade ed dia iadi a ad i e RARI Le RPRRUL D LL reds 10 4 8 Memory Width sin isn i innin nam I m 10 4 4 ROM Width 00 3a Tan eese 10 4 5 A Memory Configuration Example i 10 4 6 Specifying Word Order for Output Words i 10 5 The ROMS Directive ss eisai se Rh nnn 10 5 1 When to Use the ROMS Directive i 10 5 2 An Example of the ROMS Directive i 10 5 3 Creating a Map File of the ROMS Directive ii 10 6 The SECTIONS Directive da Rn 10 7 Output Filenames a sisse oz amr d nbi cue Daher donat x fen eee 10 7 1 Assigning Output Filenames i 10 8 Image Mode and the fill Option i 10 8 4 The image Option se 10 8 2 Specifying a Fill Value lssssssssssessesess e 10 8 8 Steps to Follow in Image Mode pp 10 9 Building a Table for an On Chip Boot Loader i 10 9 1 Description of the Boot Table i 10 9 2 The Boot Table Format ss 2 an a ame i rimarina Aa 10 9 3 How to Build the Boot Table ss sis 10 9 4 Booting From a Device Peripheral i 10 9 5 Setting the Entry Point for the Boot Table 0 00 c cece eee 10 9 6 Using the C54x Boot Loader i 10 10 Controlling the ROM Device Address i 10 10 1 Controlling the Starting Address
230. em that simulates TMS320C54x operation source file A file that contains C code or assembly language code that will be compiled or assembled to form an object file SPC Section Program counter An element of the assembler that keeps track of the current location within a section each section has its own SPC static A kind of variable whose scope is confined to a function or a program The values of static variables are not discarded when the function or pro gram is exited their previous value is resumed when the function or pro gram is re entered storage class Any entry in the symbol table that indicates how to access a symbol string table Atablethatstores symbol names that are longer than 8 charac ters symbol names of 8 characters or longer cannot be stored in the symbol table instead they are stored in the string table The name por tion of the symbol s entry points to the location of the string in the string table structure A collection of one or more variables grouped together under a single name Glossary F 7 Glossary subsection A smaller section within a section offering tighter control of the memory map See also section symbol A string of alohanumeric characters that represents an address or a value symbolic debugging The ability of a software tool to retain symbolic infor mation so that it can be used by a debugging tool such as a simulator or an emulator symbol table A portion of a CO
231. emark is an informational assembler message that is less severe than a warning If you do not specify a value for num all remarks will be suppressed generates warnings for some assembly code pipe line conflicts The assembler cannot detect all pipeline conflicts Pipeline conflicts are detected in straight line code only Upon detection of a pipe line conflict the assembler will print a warning and report the latency slots words that need to be filled by NOPs or other instructions in order to re solve the conflict puts all defined symbols in the object file s symbol table The assembler usually puts only global sym bols into the symbol table When you use s sym bols defined as labels or as assembly time con stants are also placed in the table uname undefines the predefined constant name which overrides any d options for the specified constant V X Invoking the Assembler vvalue determines the processor for which in structions are built Use one of the following for value 541 542 543 545 545lp 546lp 548 549 produces a cross reference table and appends it to the end of the listing file also adds cross refer ence information to the object file for use by the cross reference utility If you do not request a list ing file the assembler creates one anyway Assembler Description 3 7 Naming Alternate Files and Directories for Assembler Input 3 4 Naming Alternate Files and Directories f
232. endm factl macro vif N S I LD loc T multiply present factorial MPY N A by present position STL A loc Save result eval N 1 N decrement position facti recursive call endif endm Macro Language 5 23 Using Recursive and Nested Macros Example 5 16 Using Recursive Macros Continued b Algebraic example fact macro N loc n is an integer constant loc memory address n if N 2 OF 1 1 loc 1 else loc N n gt 2 so store n at loc decrement n and do the eval N 1 N factorial of n 1 factl call factl with current environment endif endm facti macro if Nol T loc multiply present factorial A T N by present position loc A Save result eval N 1 N decrement position factl recursive call endif endm 5 24 5 10 Macro Directives Summary Table 5 2 Creating Macros Mnemonic and Syntax Macro Directives Summary Description Define macro macname macro parameter parameter mlib filename mexit endm Identify library containing macro definitions Go to endm End macro definition Table 5 3 Manipulating Substitution Symbols Mnemonic and Syntax Description asg character string substitution symbol eval well defined expression substitution symbol Assign character string to substitution symbol Perform arithmetic on numeric substitution symbols Var
233. ense either express or implied is granted under any patent right copyright mask work right or other intellectual property right of TI covering or relating to any combination machine or process in which such products or services might be or are used Tl s publication of information regarding any third party s products or services does not constitute TI s approval license warranty or endorsement thereof Reproduction of information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties conditions limitations and notices Representation or reproduction of this information with alteration voids all warranties provided for an associated TI product or service is an unfair and deceptive business practice and TI is not responsible nor liable for any such use Resale of Tl s products or services with statements different from or beyond the parameters stated by TI for that products or service voids all express and any implied warranties for the associated TI product or service is an unfair and deceptive business practice and TI is not responsible nor liable for any such use Also see Standard Terms and Conditions of Sale for Semiconductor Products www ti com sc docs stdterms htm Mailing Address Texas Instruments Post Office Box 655303 Dallas Texas 75265 Copyright 2001 Texas Instruments Incorporated About This Manual Preface Read This Fi
234. entified in the link map along with the value the linker uses to fill it 7 15 4 Explicit Initialization of Uninitialized Sections An uninitialized section becomes a hole only when it is combined with an initialized section When uninitialized sections are combined with each other the resulting output section remains uninitialized However you can force the linker to initialize an uninitialized section by specifying an explicit fill value for it in the SECTIONS directive This causes the entire section to have raw data the fill value For example SECTIONS bss fill 1234h Fills bss with 1234h eo oT Note Filling Sections Because filling a section even with Os causes raw data to be generated for the entire section in the output file your output file will be very large if you specify fill values for large sections or holes Linker Description 7 69 Partial Incremental Linking 7 16 Partial Incremental Linking An output file that has been linked can be linked again with additional modules This is known as partial linking or incremental linking Partial linking allows you to partition large applications link each part separately and then link all the parts together to create the final executable program Follow these guidelines for producing a file that you will relink m Intermediate files must have relocation information Use the r option when you link the file the first time
235. entry point and memory control registers as needed Step 5 Describe your system memory configuration See Section 10 4 Understanding Memory Widths on page 10 9 and Section 10 5 The ROMS Directive on page 10 16 for details 10 9 3 2 Leaving Room for the Boot Table The complete boot table is similar to a single section containing all of the header records and data for the boot loader The address of this section is the boot table origin As part of the normal conversion process the hex conversion utility converts the boot table to hexadecimal format and maps it into the output files like any other section Be sure to leave room in your system memory for the boot table especially when you are using the ROMS directive The boot table cannot overlap other nonboot sections or unconfigured memory Usually this is not a problem typi cally a portion of memory in your system is reserved for the boot table Simply configure this memory as one or more ranges in the ROMS directive and use the bootorg option to specify the starting address Hex Conversion Utility Description 10 31 Building a Table for an On Chip Boot Loader 10 9 4 Booting From a Device Peripheral You can choose to boot from a serial or parallel port by using the SERIAL or PARALLEL keyword with the bootorg option Your selection of a keyword depends on the target device and the channel you want to use For example to boot a C54x from its serial port specify booto
236. erence list 3 37 defined field 3 12 in assembly language source 3 12 local paara symbols uses as syntax using with Tie directive 4 33 label directive length MEMORY specification length directive listing control library search algorithm library build utility described line symbolic debugging directive B 7 line number table structure A 12 to line number entry defined directive linker operator 7 40 allocation to multiple memory ranges 7 40 archive members Ns 7 45 assigning symbols assignment M TA automatic splitting of output sections e iles Faller 1 to 7 24 7 76 configured memory defined linker continued described error messages examples handling COFF sections in the development flow invoking keywords 10 7 46 MEMORY directive 7 2 options described 8 to 7 20 summary table V 6 to 7 7 output 7 3 7 17 7 7 overlay pages overview partial linking 7 70 to 7 71 section runtime address 7 44 sections in memory map output V 59 special SECTIONS directive 7 32 to 7 43 symbols 2 21 to 2 22 AED acum unconfigured memor 61 UNION statement 7 48 to 7 50 list directive same effect with option directive 4 18 lister absolute e 1 to 8 10 cross reference pM NA listing cross reference listing 4 18 enabling s cipes creating with the l option defined F 4 format B 33 to 3 36
237. es PAGE 0 and PAGE 1 Each address space contains a single address range PAGE 0 contains a default range of the entire program address space and PAGE 1 contains a default range of the en tire data address space The ROMS directive is similar to the MEMORY directive of the TMS320C54x linker both define the memory map of the target address space Each line entry in the ROMS directive defines a specific address range The general syntax is ROMS PAGE n romname origin value length value romwidth value memwidth value fill va ue files filename 1 filename2 romname origin value length value romwidth value memwidth value fill val ue files filename 1 filename2 ROMS begins the directive definition PAGE identifies a memory space for targets that use program and data address spaces If your program has been linked nor mally PAGE 0 specifies program memory and PAGE 1 speci fies data memory Each memory range after the PAGE com mand belongs to that page until you specify another PAGE If you don t include PAGE all ranges belong to page 0 romname identifies a memory range The name of the memory range may be one to eight characters in length The name has no sig nificance to the program it simply identifies the range Dupli cate memory range names are allowed origin length romwidth memwidth fill The ROMS Directive specifies the starting address of a memo
238. es You can create several source files each of which contains a single macro and use the archiver to collect these macros into a single functional group The mlib assembler directive lets you specify the name of a macro library during the assembly process the assembler will search the specified library forthe macros that you call Chapter 5 Macro Language discusses macros and macro libraries in detail Archiver Development Flow 6 2 Archiver Development Flow Figure 6 1 shows the archiver s role in the assembly language development process Both the assembler and the linker accept libraries as input Figure 6 1 Archiver Development Flow C Source files Macro Source files C compiler Translator Archiver mesemblan utility source Maco library gt s z Assembler s Library build utility Library of object files Runtime support library Linker Debugging tools Executable COFF file Cross reference lister Hex conversion utility BI PIS Absolute lister processor Archiver Description 6 3 Invoking the Archiver 6 3 Invoking the Archiver To invoke the archiver enter ar500 command option libname filename filename ar500 command is the command that invokes the archiver tells the archiver how to manipulate the library members A command can be preceded by an o
239. es a relocation entry that refers to the appropriate symbol the linker can then correctly patch relocate the refer ence This allows you to initialize memory with pointers to variables or labels You can use as many values as fit on a single line 200 characters If you use a label it points to the first word that is initialized When you use these directives in a struct endstruct sequence they define a member s size they do not initialize memory For more information about struct endstruct see Section 4 9 Assembly Time Symbol Directives on page 4 21 Initialize 16 bit Integer int uint word uword Example 1 In this example the int directive is used to initialize words 1 000000 Space 73h 2 000000 bss PAGE 128 3 000080 bss SYMPTR 3 4 000008 E856 INST LD 056h A 5 000009 000A int 10 SYMPTR 1 35 a INST 00000a 0080 00000b FFFF 00000c 0084 00000d 0008 Example 2 In this example the word directive is used to initialize words The symbol WordX points to the first word that is reserved 1 000000 0C80 WORDX word 3200 1 AB OAFh X 000001 4143 000002 FF51 000003 0058 Assembler Directives 4 59 abel Create a Relocatable Label Syntax Description Example label symbol The label directive defines a special symbol that refers to the loadtime address rather than the runtime address within the current section Most sec tions created by the assembler have relocatable addresse
240. es and related values Table A 14 Symbol Values and Storage Classes Storage Class Value Description Storage Class Value Description C AUTO Stack offset in bits C UNTAG 0 C EXT Relocatable address C TPDEF 0 C STAT Relocatable address C ENTAG 0 C REG Register number C MOE Enumeration value C LABEL Relocatable address C REGPARM Register number C MOS Offset in bits C FIELD Bit displacement C ARG Stack offset in bits C BLOCK Relocatable address C STRTAG 0 C FON Relocatable address C MOU Offset in bits C FILE 0 If a symbols storage class is C FILE the symbol s value is a pointer to the next file symbol Thus the file symbols form a one way linked list in the symbol table When there are no more file symbols the final file symbol points back to the first file symbol in the symbol table The value of a relocatable symbol is its virtual address When the linker relocates a section the value of a relocatable symbol changes accordingly Symbol Table Structure and Content A 7 6 Section Number Bytes 12 13 of a symbol table entry contain a number that indicates which section the symbol was defined in Table A 15 lists these numbers and the sections they indicate Table A 15 Section Numbers A 7 7 Type Entry Section Mnemonic Number Description N DEBUG 2 Special symbolic debugging symbol N ABS 1 Absolute symbol N UNDEF 0 Undefined external symbol N SCNUM 1 text section typical N SCNUM 2 data section typical N
241. esented together on one page Directive Directive Algebrai re GD Jengthi exta CASO oe i e Ean NIST sa sion en a iranis DOS ss a aken ep Jong ulong ss sas eid ss Dreak sse di ene NOP os RE i SS macrO oss dacs dk Re es dame byte ubyte MOND eee a keii 10 mode iss Es St crier DPI pes char uchar MMES sas nm In MIMSG 22i ai ad COPY Rr ain renis Amnollst Rr Ko ee a Ee O anewblock uua ssp i def ik acre be ay ek ren inolist ver et Rea gras idouble ux mens Koe ola so dad textes ANST iive ore Ry page i25 er ume dinolist M EIE PSN oe ion b eo bM Elseif erisso cnrt renie rus Sblock rie bs SMS0 00 ianea n GEC dace LER RS end oue pter Eddie Ot EE endif short ushort andloop sss SPACE D ENdM endstruct ee SUING oett seres cas EGU ve a Era E SIU 0 a OVAL i22 esa ep ae tabD ss P even MAG ER MMC CREE far mode MONA eM EE AILS FRE qe EROS ACNOINSE 43er Y pns UNON 22zccscv4ememrgacvexau feld Se a a a sei iR SSE MO at sod i a nee NOISION exceed bas ps global ss teet el JWmSg eoe i Rn EE RU EE EE word uword include ASIE ERE ERR i NOB a ee dabel c mete KONG ep Assembler Directives 4 25 algebraic File Contains Algebraic Assembly Source Syntax Description algebraic The algebr
242. esponding pages As a result they are both linked to load address AOOh but in different memory spaces When the program is loaded a loader can configure hardware so that each section is loaded into the appropriate memory bank Output sections S1 and S2 are placed in a union that has a run address in on chip RAM The application must move these sections at runtime before executing them You can use the symbols s1 load and s1 length to move section S1 and s2 load and s2 length to move section S2 The special symbol refers to the current run address not the current load address Linker Description 7 55 Overlay Pages Within a page you can bind output sections or use named memory areas in the usual way In Example 7 12 S1 could have been allocated S1 load 01200h page 1 a s a This binds S1 at address 1200h in page 1 You can also use page as a qualifier on the address For example S1 load 01200h PAGE 1 Low o wc If you do not specify any binding or named memory range for the section the linker allocates the section into the page wherever it can just as it normally does with a single memory space For example S2 could also be specified as S2 PAGE 2 f Because OVR MEM is the only memory on page 2 it is not necessary but acceptable to specify OVR MEM for the section 7 11 3 Page Definition Syntax To specify overlay pages as illustrated in Example 7 11 and Example 7 12 use the fo
243. evices 7 Note This example is for C54xLP devices only For non LP C54x devices see Section C 4 Example 3 Generating a Boot Table on page C 10 Example C 13 C Code for a C54xLP int array 1 2 3 4 main Note that this example is compiled with the v548 shell option Figure C 4 shows the EPROM memory system for which the output file will be generated In this application the single C54xLP device is booted from a 128K x 8 bit EPROM The requirements of the system are that the boot table must reside at EPROM memory address 0 Figure C 4 EPROM System for a C54xLP CPU C54xLP 128K x x8 ROMO Width 16 bits No ROM width 8 bits EPROM system memory width 8 bits Hex Conversion Utility Examples C 17 Example 4 Generating a Boot Table for LP Core Devices The sections that the compiler creates are divided into two categories initial ized sections sections that contain data or code and uninitialized sections sections that reserve space but contain no actual data Initialized sections created by the TMS320C54x C compiler include text cinit const and data Uninitialized sections are ignored by the hex conversion utility and are not converted Most applications require that text and cinit sections are included in the boot This allows code and information for the C boot r
244. expanded macro replacing the formal parameters with the actual arguments used at invoca tion The translator attempts to translate any macro that has the same name as a mnemonic instruction Insure that macro names are different from mnemonic instructions Translator Development Flow 11 2 Translator Development Flow Figure 6 1 shows the translator s role in the assembly language development process The assembler accepts mnemonic or algebraic syntax Figure 11 1 Translator Development Flow C Source files Macro s source fileg C compiler Archiver Mnemonic to Assembler algebraic Source Macro e library seeeee z e Assembler source eeeee COFF Pibrary of obje t Support likey 1l Debugging Executable tools COFF file Runtime gt files Hex conversion utility EPROM Absolute lister programmer Mnemonic to Algebraic Translator Description 11 3 Invoking the Translator 11 3 Invoking the Translator To invoke the translator enter mnem2alg option inputfile mnem2alg is the command that invokes the translator option specifies the translator mode see Section 11 4 Translation Modes on page 11 5 The options are t Literal mode which is the default if no option is specified e Expansion mode inputfile names the assembly source file you want to translate If you do no
245. extended each byte occupies the 8 least signifi cant bits of a full 16 bit word The assembler truncates values greater than 8 bits You can use up to 100 value parameters but the total line length cannot exceed 200 characters If you use a label it points to the location where the assembler places the first byte Note that when you use these directives in a struct endstruct sequence they define a member s size they do not initialize memory For more information about struct endstruct see Section 4 9 Assembly Time Symbol Directives on page 4 21 In this example 8 bit values 10 1 abc and a are placed into consecutive words in memory The label strx has the value 100h which is the location of the first initialized word 1 0000 Space 100h 16 2 000100 000a STRX byte 10 1 abc a 000101 00ff 000102 0061 000103 0062 000104 0063 000105 0061 Assembler Directives 4 33 clink Conditionally Leave Section Out of COFF Output Syntax Description Example 4 34 clink section name The clink directive sets up conditional linking for a section by setting the STYP CLINK flag in the type field for section name The clink directive can be applied to initialized or uninitialized sections If clink is used without a section name it applies to the current initialized section If clink is applied to an uninitialized section the section name is required The section name is significant to 200 characters
246. ey are encountered Each output section is placed into the first available memory space considering alignment where neces sary ee Note The PAGE Option If you do not use the PAGE option to explicitly specify a memory space for an output section the linker allocates the section into PAGE 0 This occurs even if PAGE 0 has no room and other pages do To use a page other than PAGE 0 you must specify the page with the SECTIONS directive LLLLLLLL Special Section Types DSECT COPY and NOLOAD 7 13 Special Section Types DSECT COPY and NOLOAD You can assign three special type designations to output sections DSECT COPY and NOLOAD These types affect the way that the program is treated when it is linked and loaded You can assign a type to a section by placing the type enclosed in parentheses after the section definition For example S ECTIONS secl 2000h DSECT fl obj sec2 4000h COPY 2 0bj sec3 6000h NOLOAD f3 0bj The DSECT type creates a dummy section with the following qualities B Itis not included in the output section memory allocation It takes up no memory and is not included in the memory map listing B lt can overlay other output sections other DSECTs and unconfigured memory B Global symbols defined in a dummy section are relocated normally They appear in the output module s symbol table with the same
247. finition that are assembled each time a macro is invoked named section An initialized section that is defined with a sect directive object file A file that has been assembled or linked and contains machine language object code object format converter A program that converts COFF object files into Intel format or Tektronix format object files Glossary F 5 Glossary object library An archive library made up of individual object files operands The arguments or parameters of an assembly language instruction assembler directive or macro directive optional header A portion of a COFF object file that the linker uses to perform relocation at download time options Command parameters that allow you to request additional or specific functions when you invoke a software tool output module A linked executable object file that can be downloaded and executed on a target system output section A final allocated section in a linked executable module overlay page A section of physical memory that is mapped into the same address range as another section of memory A hardware switch deter mines which range is active partial linking The linking of a file that will be linked again quiet run Suppresses the normal banner and the progress information RAM model An autoinitialization model used by the linker when linking C code The linker uses this model when you invoke the linker with the cr option The RAM m
248. first encounters a data directive the data section is empty The state ments following this first data directive are assembled into the data section until the assembler encounters a text or sect directive If the assembler encounters subsequent data directives it adds the statements following these data directives to the statements already in the data section This creates a single data section that can be allocated contiguously into memory Initialized subsections can be created with the sect directive The assembler treats initialized subsections in the same manner as initialized sections See subsection 2 3 4 Subsections on page 2 9 for more information on creating subsections Introduction to Common Object File Format 2 7 How the Assembler Handles Sections 2 3 3 Named Sections Named sections are sections that you create You can use them like the de fault text data and bss sections but they are assembled separately For example repeated use of the text directive builds up a single text section in the object file When linked this text section is allocated into memory as asingle unit Suppose there is a portion of executable code perhaps an initiali zation routine that you don t want allocated with text If you assemble this segment of code into a named section it is assembled separately from text and you can allocate it into memory separately You can also assemble initial ized data that is separate fr
249. for the final time does not usually contain relocation entries Figure A 1 illustrates the overall object file structure Figure A 1 COFF File Structure file header optional file header section 1 header section n header section 1 raw data section n raw data section 1 relocation information section n relocation information section 1 line numbers section n line numbers symbol table string table A 2 section headers raw data executable code andinitialized data relocation information line number entries COFF File Structure Figure A 2 shows a typical example of a COFF object file that contains the three default sections text data and bss and a named section referred to as lt named gt By default the tools place sections into the object file in the following order text data initialized named sections bss and uninitialized named sections Although uninitialized sections have section headers notice thatthey have no raw data relocation information or line number entries This is because the bss and usect directives simply reserve space for uninitialized data uninitialized sections contain no actual code Figure A 2 COFF Object File file header text section header data section header bss section header section headers lt named gt section section header text raw data data raw
250. from the library are extracted and they are extracted only once You can use the archiver to create a macro library by simply including the desired files in an archive A macro library is no different from any other archive except that the assembler expects the macro library to contain macro definitions The assembler expects only macro definitions in a macro library putting object code or miscellaneous source files into the library may produce undesirable results Using Conditional Assembly in Macros 5 5 Using Conditional Assembly in Macros The conditional assembly directives are if elseif else endif and loop break endloop They can be nested within each other up to 32 levels deep The format of a conditional block is if well defined expression elseif well defined expression else well defined expression endif The elseif and else directives are optional in conditional assembly The elseif directive can be used more than once within a conditional assembly code block When elseif and else are omitted and when the if expression is false 0 the assembler continues to the code following the endif directive For more information on the if elseif else endif directives see page 4 56 The loop break endloop directives enable you to assemble a code block repeatedly The format of a repeatable block is loop well defined expression break well defined expression endloop The
251. fy the information within the brackets you don t enter the brackets themselves This is an example of a command that has an optional parameter hex500 options filename The hex500 command has two parameters The first parameter options is optional Since options is plural you may select several options The second parameter filename is required Notational Conventions In assembler syntax statements column 1 is reserved for the first character of a label or symbol If the label or symbol is optional it is usually not shown If it is a required parameter then it will be shown starting against the left margin of the shaded box as in the example below No instruction command directive or parameter other than a symbol or label should begin in column 1 symbol usect section name size in words blocking flag alignment flag The symbolis required for the usect directive and must begin in column 1 The section name must be enclosed in quotes and the section size in words must be separated from the section name by a comma The blocking flag and alignment flag are optional and if used must be separated by commas Some directives can have a varying number of parameters For example the byte directive can have up to 100 parameters The syntax for this directive is byte value valuen Note that byte does not begin in column 1 This syntax shows that byte m
252. g data Example C 3 shows the hex command file with all of the selected options Example C 3 A Hex Command File for Two 8 Bit EPROMs test out COFF object input file ud map examplel mxp x n Set parameters for EPROM programmer Fann zem i Select Intel format byte Select byte increment for addresses A Set options required to describe EPROM memory system pm f memwidth 16 Set EPROM system memory width romwidth 8 Set physical width of ROM device xy ROMS PAGE 0 EPROM origin 0x00 length 0x10000 files low8 bit upp8 bit SECTIONS outsec paddr 0x10 Figure C 2 a shows the contents of the converted file for ROMO low8 bit containing the lower 8 bits Figure C 2 b shows the contents of the converted file for ROM1 upp8 bit containing the upper 8 bits of data Hex Conversion Utility Examples C 5 Example 1 Building a Command File for Two 8 Bit EPROMS Figure C 2 Data From Output File a low8 bit Lower Bits Data from converted output file 040010003478BBDDA8 00000001FF Corresponding map in EPROM ROMO See Example C 1 on page C 2 0x0010 b upp8 bit Upper Bits Data from converted output file 040010001256AACCOE 00000001FF Corresponding map in EPROM ROM1 See Example C 1 on page C 2 0x0010 Example 1 Building a Command File fo
253. ge of the entire program address space and PAGE 1 contains a default range of the en tire data address space If nothing is loaded into a particular page no output is created for that page Use the ROMS directive when you want to Program large amounts of data into fixed size ROMs When you spe cify memory ranges corresponding to the length of your ROMS the utility automatically breaks the output into blocks that fit into the ROMs Restrict output to certain segments You can also use the ROMS direc tive to restrict the conversion to a certain segment or segments of the tar get address space The utility does not convert the data that falls outside of the ranges defined by the ROMS directive Sections can span range boundaries the utility splits them at the boundary into multiple ranges If a section falls completely outside any of the ranges you define the utility does not convert that section and issues no messages or warnings In this way you can exclude sections without listing them by name with the SECTIONS directive However if a section falls partially in a range and partially in unconfigured memory the utility issues a warning and converts only the part within the range Use image mode When you use the image option you must use a ROMS directive Each range is filled completely so that each output file in The ROMS Directive arange contains data for the whole range Gaps before between or after sections are fi
254. get memory so that you can define the types of memory your system contains and the address ranges they occupy The linker maintains the model as it allocates output sections and uses it to determine which memory locations can be used for object code The memory configurations of TMS320C54x systems differ from application to application The MEMORY directive allows you to specify a variety of configurations After you use MEMORY to define a memory model you can use the SECTIONS directive to allocate output sections into defined memory Refer to Section 2 4 How the Linker Handles Sections on page 2 13 for details on how the linker handles sections Refer to Section 2 5 Relocation on page 2 16 for information on the relocation of sections 7 7 1 Default Memory Model The assembler enables you to assemble code for the TMS320C54x device The assembler inserts a field in the output file s header identifying the device The linker reads this information from the object file s header If you do not use the MEMORY directive the linker uses a default memory model specific to the named device For more information about the default memory model see subsection 7 12 1 Allocation Algorithm on page 7 58 7 7 2 MEMORY Directive Syntax The MEMORY directive identifies ranges of memory that are physically present in the target system and can be used by a program Each memory range has a name a starting address and a length C54x devices have separa
255. gram depending on the execu tion environment Two common situations are described below The TMS320C54x debugging tools including the software simulator XDS51x emulator and software development system have built in load ers Each of these tools contains a LOAD command that invokes a loader the loader reads the executable file and copies the program into target memory You can use the hex conversion utility hex500 which is shipped as part of the assembly language package to convert the executable COFF object module into one of several object file formats You can then use the converted file with an EPROM programmer to burn the program into an EPROM Symbols in a COFF File 2 8 Symbols in a COFF File A COFF file contains a symbol table that stores information about symbols in the program The linker uses this table when it performs relocation Debugging tools can also use the symbol table to provide symbolic debugging 2 8 1 External Symbols External symbols are symbols that are defined in one module and referenced in another module You can use the def ref or global directives to identify symbols as external def Defined in the current module and used in another module ref Referenced in the current module but defined in another module global May be either of the above The following code segment illustrates these definitions x ADD 56h A Define x B y Reference y def x DEF of x ref y R
256. h RSBX INTM enable ints endm Reset and interrupt vectors i Sect reset RESET B init INTO B ISRO INT1 B ISR1 INT2 B ISRZ Sect ints TINT B time RINT B rcv XINT B xmt USER B proc Initialize processor a ck ck Ck ck ck KKK KKK ck ck Ck ck 0k ck ck ck ck ck ck ck ck ck ck ck ok ck ck ck kk kk kv kx kx kx ko ko init initmac initialize macro SSBX OVM disable oflow LD 40 DP dp 0 LD 7 ARP arp ar7 LD 037h A acc 03fh RSBX INTM enable ints Vy ee Field 1 Field 2 Field 3 Field 4 Assembler Description 3 35 Source Listings Example 3 4 Assembler Listing Continued b Algebraic example 19 20 21 22 23 24 25 26 27 28 29 30 31 32 PPPPPPP 000000 000000 F073 000001 0008 000002 F073 000003 0000 000004 F073 000005 0000 000006 F073 000007 0000 000000 000000 F073 000001 0000 000002 F073 000003 0000 000004 F073 000005 0000
257. h for these formats is 8 bits Tl Tagged is a 16 bit format the default ROM width for Tl Tagged is 16 bits Note The TI Tagged Format Is 16 Bits Wide You cannot change the ROM width of the Tl Tagged format The Tl Tagged format supports a 16 bit ROM width only You can change ROM width except for Tl Tagged by Using the romwidth option This changes the ROM width value for the entire COFF file DD Setting the romwidth parameter of the ROMS directive This changes the ROM width value for a specific ROM address range and overrides the romwidth option for that range See Section 10 5 The ROMS Directive on page 10 16 For both methods use a value that is a power of 2 greater than or equal to 8 If you select a ROM width that is wider than the natural size of the output format 16 bits for Tl Tagged or 8 bits for all others the utility simply writes multibyte fields into the file Figure 10 4 illustrates how the target memory and ROM widths are related to one another Understanding Memory Widths Figure 10 4 Data Memory and ROM Wiaths Data after phase of hex utility Data after phase II of hex utility Data after phase III of hex utility Source file Word OAABBCDDh word 01122344h Data width 16 fixed Memory widths variable uu S BS A memwidth 16 AABB ES Output files romwidth 16 o file wrd romwidth
258. haracter strings to built in functions described directives that define to expansion listing 4 18 4 83 forcing substitution in macros 5 6lto maximum number per macro passing commas and semicolons recursive substitution subscripted substitution 5 12 to 13 var macro directive suppressing assembler remarks swwsr hex conversion utility option sym symbolic debugging directive symbol defined definitions names symbol table creating entries 2 22 defined described entry from sym directive B 11 index placing unresolved symbols in special symbols used in A 16 to stripping entries structure and content A 14 to values Index 14 symbolic constants symbolic debugging b linker option disable merge for linker 7 10 enumeration definitions B 9 file identification function definitions line number entries B 7 member definitions producing error messages in macros 5 19 s assembler option B stripping symbolic information 7 17 structure definitions symbols table structure and content A 14 to A 29 union definitions symbols assembler defined assigning values to at link time 7 62 to 7 65 attributes case character strings cross reference lister cross reference listing defined by the assembler p 21 to 2 24 by the linker only for C support 65 described 2 21 toj2 22 external global number of statements that reference predefined symbol memory mapped registe
259. have one of two values short integer 2 If this field is not 0 this is the line number of a line in 1 If this field is O this is the first line of a function entry C C source code Figure A 4 shows how line number entries are grouped into blocks Figure A 4 Line Number Blocks Symbol Index 1 0 physical address line number physical address line number Symbol Index n 0 physical address line number physical address As Figure A 4 shows each entry is divided as follows Forthe first line of a function bytes 0 3 point to the name of a symbol or a function in the symbol table and bytes 4 5 contain a 0 which indicates the beginning of a block line number Line Number Table Structure Forthe remaining lines in a function bytes 0 3 show the physical address the number of words created by a line of C C source and bytes 4 5 show the address of the original C C source relative to its appearance in the C C source program The line number entry table can contain many of these blocks Figure A 5 illustrates line number entries for a function named XYZ As shown the function name is entered as a symbol in the symbol table The first portion on XYZ s block of line number entries points to the function name in the symbol table Assume that the original function in the C C source con tained three lines of code The first line of code produces 4 word
260. he expression up to a elseif else or endif If the expression evaluates to false 0 the assembler assembles code that follows a elseif if present else if present or endif if no elseif or else is present The elseif directive identifies a block of code to be assembled when the if expression is false 0 and the elseif expression is true nonzero When the elseif expression is false the assembler continues to the next elseif if pres ent else if present or endif if no elseif or else is present The elseif di rective is optional in the conditional blocks and more than one elseif can be used If an expression is false and there is no elseif statement the assembler continues with the code that follows a else if present or a endif The else directive identifies a block of code that the assembler assembles when the if expression and all elseif expressions are false 0 This directive is optional in the conditional block if an expression is false and there is no else statement the assembler continues with the code that follows the endif The endif directive terminates a conditional block The elseif and else directives can be used in the same conditional assembly block and the elseif directive can be used more than once within a conditional assembly block For information about relational operators see subsection 3 9 4 Conditional Expressions on page 3 27 Example co 1001 CO
261. he linker then uses these entries to patch the references after the symbols are relocated Example 2 2 contains a code segment for the C54x that generates relocation entries Example 2 2 Code That Generates Relocation Entries 2 16 a Mnemonic example 1 ref X 2 ref Z 3 000000 text 4 000000 F073 B Y Generates a Relocation Entry 000001 0006 5 000002 F073 B Z Generates a Relocation Entry 000003 0000 6 000004 F020 LD X A Generates a Relocation Entry 000005 0000 5 000006 F7E0 Y RESET b Algebraic example 1 ref X 2 ref Z 3 000000 text 4 000000 F073 goto ba Generates a Relocation Entry 000001 0006 5 000002 F073 B Z Generates a Relocation Entry 000003 0000 6 000004 F020 A X Generates a Relocation Entry 000005 0000 7 000006 F7EO Y reset Helocation In Example 2 2 both symbols X Y and Z are relocatable Y is defined in the text section of this module X and Z are defined in another module When the code is assembled X and Z have a value of 0 the assembler assumes all un defined external symbols have values of 0 and Y has a value of 6 relative to address 0 in the text section The assembler generates relocation entries for X Y and Z The references to X and Z are external references indicated by the character in the listing The reference to Y is to an internally defined relocatable symbol indicated by the character in t
262. he listing After the code is linked suppose that X is relocated to address 7100h Suppose also that the text section is relocated to begin at address 7200h Y now has a relocated value of 7204h The linker uses the two relocation entries to patch the two references in the object code 073 B Y becomes 073 0004 7204 020 LD X A becomes 020 0000 7100 Each section in a COFF object file has a table of relocation entries The table contains one relocation entry for each relocatable reference in the section The linker usually removes relocation entries after it uses them This prevents the output file from being relocated again if it is relinked or when it is loaded A file that contains no relocation entries is an absolute file all its addresses are absolute addresses If you want the linker to retain relocation entries in voke the linker with the r option 2 5 4 Relocation Issues The linker may warn you about certain relocation issues In an assembly program if an instruction with a PC relative field contains a reference to a symbol label or address the relative displacementis expected to fit in the instruction s field If the displacement doesn t fit into the field be cause the referenced item s location is too far away the linker issues an error For example the linker will issue an error message when an instruction with an 8 bit unsigned PC relative field references a symbol located 256 or more bytes
263. he section data identifies portions of code in the data section The data section usually contains initialized data sect defines initialized named sections and associates subsequent code or data with that section A section defined with sect can contain execut able code or data text identifies portions of code in the text section The text section usually contains executable code usect reserves space in an uninitialized named section The usect directive is similar to the bss directive but it allows you to reserve space separately from the bss section Chapter 2 ntroduction to Common Object File Format discusses COFF sections in detail Example 4 1 shows how you can use sections directives to associate code and data with the proper sections This is an output listing column 1 shows line numbers and column 2 shows the SPC values Each section has its own pro gram counter or SPC When code is first placed in a section its SPC equals 0 When you resume assembling into a section after other code is assembled the section s SPC resumes counting as if there had been no intervening code The directives in Example 4 1 perform the following tasks text initializes words with the values 1 2 3 4 5 6 7 and 8 data initializes words with the values 9 10 11 12 13 14 15 and 16 var_defs initializes words with the values 17 and 18 bss reserves 19 words usect reserves 20 words The bss and us
264. hm on page 7 58 Linker Description 7 19 Linker Options 7 4 20 Exhaustively Read Libraries x Option The linker normally reads input files including archive libraries only once when they are encountered on the command line or inthe command file When anarchive is read any members that resolve references to undefined symbols are included in the link If an input file later references a symbol defined in a previously read archive library the reference will not be resolved With the x option you can force the linker to reread all libraries The linker rereads libraries until no more references can be resolved Linking using the x option may be slower so you should use it only as needed For example if a lib contains a reference to a symbol defined in b lib and b lib contains a reference to a symbol defined in a lib you can resolve the mutual dependencies by listing one of the libraries twice as in 1nk500 la lib lb lib la lib or you can force the linker to do it for you ink500 x la lib lb lib Linker Command Files 7 5 Linker Command Files Linker command files allow you to put linking information in a file this is useful when you invoke the linker often with the same information Linker command files are also useful because they allow you to use the MEMORY and SECTIONS directives to customize your application You must use these directives in a command file you cannot use them on the command line Linker
265. ht characters or less this field has type character The name is padded with nulls if necessary and stored in bytes 0 7 D Ifthe symbol name is greater than 8 characters this field is treated as two long integers The entire symbol name is stored in the string table Bytes 0 3 contain 0 and bytes 4 7 are an offset into the string table A 7 3 String Table Structure Symbol names that are longer than eight characters are stored in the string table The field in the symbol table entry that would normally contain the sym bol s name contains instead a pointer to the symbol s name in the string table Names are stored contiguously in the string table delimited by a null byte The first four bytes of the string table contain the size of the string table in bytes thus offsets into the string table are greater than or equal to four Figure A 9 is a string table that contains two symbol names Adaptive Filter and Fourier Transform The index inthe string table is 4 for Adaptive Filter and 20 for Fourier Transform Figure A 9 String Table Symbol Table Structure and Content A 7 4 Storage Classes Byte 16 of the symbol table entry indicates the storage class of the symbol Storage classes refer to the method in which the C C compiler accesses a symbol Table A 12 lists valid storage classes Table A 12 Symbol Storage Classes Mnemonic Value Storage Class Mnemonic Value Storage Class C NULL 0 No storage class C UNTAG 12
266. i De le Time a ai A 7 8 The SECTIONS Directive cso gs sa i Te n 7 8 1 Default Configuration 0 7 8 2 SECTIONS Directive Syntax se 0000 0 i i aR A LOS ANOCAION esneiticeteea dented iat hattest tt E heen AS 7 9 Specifying a Section s Runtime Address i 7 9 1 Specifying Load and Run Addresses i 7 9 2 Uninitialized Sections snes drip oh eee 7 9 8 Referring to the Load Address by Using the label Directive 7 10 Using UNION and GROUP Statements i 7 10 1 Overlaying Sections With the UNION Statement i 7 10 2 Grouping Output Sections Together pp 7 10 3 Nesting UNIONs and GROUPS pp 7 10 4 Checking the Consistency of Allocators pp FAV Overlay Pages senci secs a ee E oud E RE teri d bee T d n e Ruso aa 7 11 1 Using the MEMORY Directive to Define Overlay Pages 7 11 2 Using Overlay Pages With the SECTIONS Directive 7 11 3 Page Definition Syntax sng 7 12 Default Allocation Algorithm et 7 12 1 Allocation Algorithm sane 7 12 2 General Rules for Output Sections pp 10 Contents 7 13 Special Section Types DSECT COPY and NOLOAD isi 7 14 Assigning Symbols at Link Time i 7 14 1 Syntax of Assignment Statements i 7 14 2 Assigning the SPC to a Symbol i 7 14 3 Assignment Expressions sd es md ere 7 14 4 Symbols Defined by the Linker 0 7 14 5 Symbols Defined Only For C Support c or cr Option 7 15 Creating and Filling Holes Son sped ee De III 7 15 1 Initialized and Uninitialized S
267. iate Value for Directives The immediate value mode is primarily used with instructions In some cases it can also be used with the operands of directives It is not usually necessary to use the immediate value mode for directives Compare the following statements ADD 10 A byte 10 In the first statement the immediate value mode is necessary to tell the assembler to add the value 10 to accumulator A In the second statement however immediate value is not used the assembler expects the operand to be a value and initializes a byte with the value 10 Assembler Description 3 13 Source Statement Format 3 5 4 Algebraic Instruction Field In algebraic assembly the instruction field is a combination of the mnemonic and operand fields used in mnemonic syntax You generally do not have a mnemonic followed by operands Rather the operands are part of the overall statement The following items describe how to use the instruction field for al gebraic syntax Generally operands are not separated by commas Some algebraic instructions however consist of a mnemonic and operands For algebraic statements of this type commas are used to separate oper ands For example Ims Xmem Ymem Expressions that have more than one term that is used as a single oper and must be delimited with parentheses This rule does not apply to state ments using a function call format since they are already set off with parentheses For example cons
268. ider A B amp 1 lt lt sym lt lt 5 The expression 1 sym is used as a single operand and is therefore set off with parentheses All register names are reserved _ For algebraic instructions that consist of a mnemonic and operands the mnemonic word is reserved 3 5 5 Comment Field 8 14 A comment can begin in any column and extends to the end of the source line A comment can contain any ASCII character including blanks Comments are printed in the assembly source listing but they do not affect the assembly A source statementthat contains only a commentis valid If it begins in column 1 it can start with a semicolon or asterisk Comments that begin any where else on the line must begin with a semicolon The asterisk identifies a comment only if it appears in column 1 Constants 3 6 Constants The assembler supports six types of constants Binary integer Octal integer Decimal integer Hexadecimal integer Character Assembly time Floating point O O O O O O L The assembler maintains each constant internally as a 32 bit quantity Constants are not sign extended For example the constant OFFH is equal to OOFF base 16 or 255 base 10 it does not equal 1 3 6 4 Binary Integers A binary integer constant is a string of up to 16 binary digits Os and 1s followed by the suffix B or b If fewer than 16 digits are specified the assembler right justifies the value and zero fills the u
269. ides a way to allocate several sections at the same runtime address In Example 7 7 the bss sections from file1 obj and file2 obj are allocated at the same address in RAM In the memory map the union occupies as much space as its largest component The components of a union remain independent sections they are simply allocated together as a unit Example 7 7 The UNION Statement n ECTIONS text load ROM UNION run RAM bssl1 filel obj bss bss2 file2 0bj bss bss3 run RAM globals obj bss Allocation of a section as part of a union affects only its run address Under no circumstances can sections be overlaid for loading If an initialized section is aunion member an initialized section has raw data such as text its load allocation must be separately specified For example Example 7 8 Separate Load Addresses for UNION Sections UNION run RAM textl load text2 load ROM filel obj text ROM file2 0bj text Using UNION and GROUP Statements Figure 7 5 Memory Allocation Shown in Example 7 7 and Example 7 8 Allocation for Example 7 7 Allocation for Example 7 8 RAM text 2 run Sections can run L S as aunion This is runtime allocation only Copies at runtime text 1 run text 1 load Sections cannot J
270. idth emsg fcnolist mmsg Ssnolist wmsg You can use the drlist directive to turn on the listing of these directives again The listing file contains a listing of false conditional blocks that do not gen erate code The fclist and fcnolist directives turn this listing on and off You can use the fclist directive to list false conditional blocks exactly as they appear in the source code This is the default behavior of the assembler You can use the fcnolist directive to list only the conditional blocks that are actually assembled The length directive controls the page length of the listing file You can use this directive to adjust listings for various output devices The list and nolist directives turn the output listing on and off You can use the nolist directive to stop the assembler from printing selected source statements in the listing file Use the list directive to turn the listing on again Thelisting file contains a listing of macro expansions and loop blocks The mlist and mnolist directives turn this listing on and off You can use the mlist directive to print all macro expansions and loop blocks to the listing the default behavior of the assembler and the mnolist directive to suppress this listing The option directive controls certain features in the listing file This directive has the following operands A turns on listing of all directives and data and subsequent expan sions mac
271. ield for the block in the boot table The section content is then treated as raw data for that block Building a Table for an On Chip Boot Loader The hex conversion utility does not use the section run adaress When linking you need not worry about the ROM address or the construction of the boot table the hex conversion utility handles this Step 2 Identify the bootable sections You can use the boot option to tell the hex conversion utility to configure all sections for boot loading Or you can use a SECTIONS directive to select specific sections to be configured see Section 10 6 The SECTIONS Directive on page 10 22 Note that if you use a SECTIONS directive the boot option is ignored Step 3 Set the ROM address of the boot table Use the bootorg option to set the source address of the complete table For example if you are using the C54x and booting from memory location 8000h specify bootorg 8000h The address field in the the hex conversion utility output file will then start at 8000h If you use bootorg SERIAL or bootorg PARALLEL or if you do not use the bootorg option at all the utility places the table at the origin of the first memory range in a ROMS directive If you do not use a ROMS directive the table will start at the first section load address There is also a bootpage option for starting the table somewhere other than page O Step 4 Set boot loader specific options Set such options as
272. ield of the hex conver sion utility output file is a function of the load address as given in the linker command file and the hex conversion utility parameter values The rela tionship is summarized as follows out file addrt load addr x data width mem width out file addr is the address of the output file load addr is the linker assigned load address data width is specified as 16 bits for the TMS320C54x devices See subsection 10 4 2 Data Width on page 10 10 mem width is the memory width of the memory system You can specify the memory width by the memwidth option or by the memwidth parameter inside the ROMS directive See subsection 10 4 3 Memory Width on page 10 10 T If paddr is not specified The value of data width divided by memory width is a correction factor for address generation When data width is larger than memory width the correction factor expands the address space For example if the load address is 0 x 1 and data width divided by memory width is 2 the output file address field would be 0 x2 The data is split into two consecutive loca tions the size of the memory width 2 The paddr parameter of the SECTIONS directive When the paddr parameter is specified for a section the hex conversion utility bypasses Hex Conversion Utility Description 10 35 Controlling the ROM Device Adaress the section load address and places the section in the address specified by paddr The relationship between the
273. ies the current source file name The line directive identifies the line number of a C C source statement These symbolic debugging directives are not usually listed in the assembly language file that the compiler creates If you want them to be listed invoke the compiler shell with the g option as shown below c1500 g input file This appendix contains an alphabetical directory of the symbolic debugging directives With the exception of the file directive each directive contains an example of C C source and the resulting assembly language code B 1 block endblock Define a Block Syntax block beginning line number endblock ending line number Description The block and endblock directives specify the beginning and end of a C C block The line numbers are optional they specify the location in the source file where the block is defined Block definitions can be nested The assembler will detect improper block nesting Example Following is an example of C source that defines a block and the resulting assembly language code C source Beginning of a block int a b ab End of a block Resulting assembly language code block 8 sym a 2 4 1 16 sym _b 3 4 1 16 line 9 LD SP 3 A cycle 3 STL A SP 2 Cycle 4 endblock 10 Syntax Description Example Supply a File Identifier file file filename The file directive allows a debugger to map locations in memory backto line
274. ill place the raw data for the section Any references to the section such as labels in it refer to its run address The application must copy the section from its load address to its run address this does not happen automatically simply because you specify a separate run address For an example that illustrates how to move a block of code at runtime see Example 7 6 on page 7 46 If you provide only one allocation either load or run for a section the section is allocated only once and will load and run atthe same address If you provide both allocations the section is actually allocated as if it were two different sections of the same size Uninitialized sections such as bss are not loaded so the only significant address is the run address The linker allocates uninitialized sections only once if you specify both run and load addresses the linker warns you and ignores the load address For a complete description of runtime relocation see Section 7 9 Specifying a Section s Runtime Address on page 7 44 Introduction to Common Object File Format 2 19 Loading a Program 2 7 Loading a Program 2 20 The linker produces executable COFF object modules An executable object file has the same COFF format as object files that are used as linker input the sections in an executable object file however are combined and relocated so that they can be loaded directly into target memory Several methods can be used for loading a pro
275. in this instance Executing the linker with the command file in Example C 8 on page C 12 yields a COFF file that can be used as inputto the hex conversion utility to build the desired boot table The hex conversion utility has options that describe the requirements for the EPROM programmer and options that describe the EPROM memory system For Example 3 assume that the EPROM programmer has only one require ment that the hex file be in Intel format In the EPROM memory system illustrated in Figure C 3 on page C 10 the EPROM system memory width is 8 bits and the physical ROM width is 8 bits You must set the following options in the hex command file to reflect the requirements of the system Option Description Create Intel format memwidth 8 Set EPROM system memory width to 8 romwidth 8 Set physical ROM width to 8 Because the application requires the building of a boot table for parallel boot mode you must set the following options in the hex command file to reflect the requirements of the system Option Description boot Create a boot load table bootorg 0x0000 Place boot table at address 0x0000 Example 3 Generating a Boot Table Example C 10 Hex Command File for Converting a COFF File boot out Input COFF file i Select Intel format n4 map boot2 map o boot hex Name the hex output file memwidth 8 Set EPROM system memory width romwidth 8 Set physical ROM width
276. ing a Boot Table for LP Core Devices 05 Assembler Error Messages sseeseuuees eee eee nnn nn nnnm Lists the error messages that the assembler and linker issue and gives a description of the condition s that caused each error Linker Error Messages seseeeeeeeeeeeer hh n nnn n nnn Lists the error messages that the assembler and linker issue and gives a description of the condition s that caused each error Glossary P ERE F 1 Defines terms and acronyms used in this book Contents xiii Figures 1 1 TMS320C54x Software Development Flow i 2 1 Partitioning Memory Into Logical Blocks i 2 2 Object Code Generated by the File in Example 2 1 0 0 cece eee eens 2 3 Combining Input Sections to Form an Executable Object Module 3 1 Assembler Development Flow i 4 1 The space and bes Directives i 4 2 The eld Directive sn 4 3 Initialization Directives ei 4 4 The align Directive oss errcrerrrrirs teenrit s ara N SEENE e Rm 4 5 Allocating bss Blocks Within a Page i 4 6 The feld DIr clive cie ek AAE AAR ERARE ES 4 7 The usect Dreti Mice be oie ai ad adage debe dee ee dae ee ar ERR 6 1 Archiver Development Flow i 7 1 Linker Development Flow i 7 2 Memory Map Defined in Example 7 3 2 0000 ee 7 3 Section Allocation Defined by Example 7 4 i 7 4 Runtime Execution of Example 7 6 i 7 5 Memory Allocation Shown in Example 7 7 and Example
277. ing counts These counts alert you to problems in your code and are especially useful during debugging emsg mmsg wmsg sends error messages to the listing file The emsg directive generates errors in the same manner as the assembler incrementing the error count and preventing the assembler from producing an object file sends assembly time messages to the listing file The mmsg directive functions in the same manner as the emsg directive but does not set the error count or prevent the creation of an object file sends warning messages to the listing file The wmsg directive functions in the same manner as the emsg directive but it increments the warning count and does not prevent the generation of an object file Macro comments are comments that appear in the definition of the macro but do not show up in the expansion of the macro An exclamation point in column 1 identifies a macro comment If you want your comments to appear in the macro expansion precede your comment with an asterisk or semicolon Example 5 14 shows user messages in macros Macro Language 5 19 Producing Messages in Macros Example 5 14 Producing Messages in a Macro PRPRPPRPRPRPRPRPRPEE PR O 01 5 CO 15 16 0000 0000 0000 0000 TT 18 0000 US Error testparam 00 00 1002 01 1101 02 F500 03 ER RROR KKKKK o Warnings macro x y if Ssymlen x 0 n e
278. ing is an example of a structure definition C source struct doc char title char group int job_number doc info Resulting assembly language code stag doc 48 member title 0 2 8 16 member group 16 2 8 16 member job number 32 4 8 16 eos D Name is the name of the structure enumeration or union The first 32 characters of the name are significant This is a required parameter Sizeis the number of bits the structure enumeration or union occupies in memory This is an optional parameter if omitted the size is unspeci Example 2 Example 3 Define a Structure Stag etag utag eos Following is an example of a union definition C source union u tag int vall float val2 char valge valu Resulting assembly language code utag u tag 32 member _vall 0 4 11 16 member _val2 0 6 11 32 member _valc 0 2 11 16 eos Following is an example of an enumeration definition C Source enum o ty reg 1 reg 2 result optypes Resulting assembly language code etag o ty 16 member reg 1 0 4 16 16 member reg 2 1 4 16 16 member _result 2 4 16 16 eos Symbolic Debugging Directives B 9 Sym Define a Symbol Syntax Description Example sym name value type storage class size tag dims The sym directive specifies symbolic debug information about a global vari able local variable or a function DD Nameisthe name of the variable that is put
279. inker Directives a obj b obj c obj Input filenames o prog out m prog map Options xf MEMORY MEMORY directive Xy RAM origin 100h length 0100h ROM origin 01000h length 0100h SECTIONS SECTIONS directive ey text gt ROM data gt RAM bss RAM Linker Description 7 23 Linker Command Files 7 5 1 Reserved Names in Linker Command Files The following names are reserved as keywords for linker directives Do not use them as symbol or section names in a command file align GROUP origin ALIGN lowercase L ORIGIN attr len page ATTR length PAGE block LENGTH range BLOCK load run COPY LOAD RUN DSECT MEMORY SECTIONS f NOLOAD spare fill o type FILL org TYPE group UNION 7 5 2 Constants in Command Files 7 24 Constants can be specified with either of two syntax schemes the scheme used for specifying decimal octal or hexadecimal constants used in the assembler see Section 3 6 Constants on page 3 15 or the scheme used for integer constants in C syntax Examples Decimal Octal Hexadecimal Assembler Format 32 40q 20h C Format 32 040 0x20 Object Libraries 7 6 Object Libraries An object library is a partitioned archive file that contains complete object files as members Usually a group of related modules are grouped together into alibrary When you specify an object library as linker input the linker includes any members ofthe library that define exis
280. inker also has an align operator that allows a symbol to be aligned on an n word boundary within an output sec tion n is a power of 2 For example the expression align 16 aligns the SPC within the current section on the next 16 word boundary Because the align operator is a function of the current SPC it can be used only uo in the same context as that is within a SECTIONS directive Table 7 1 Operators Used in Expressions Precedence 7 64 Symbols Operators Evaluation Unary plus minus 1s complement Right to left Multiplication division modulo Left to right Addition subtraction Left to right lt lt gt gt Left shift right shift Left to right lt lt gt gt Less than LT or equal greater than Left to right GT or equal l Not equal to equal to Left to right amp Bitwise AND Left to right A Bitwise exclusive OR Left to right Bitwise OR Left to right Note Unary and have higher precedence than the binary forms Assigning Symbols at Link Time 7 14 4 Symbols Defined by the Linker The linker automatically defines several symbols that a program can use at runtime to determine where a section is linked These symbols are external So they appear in the link map They can be accessed in any assembly language module if they are declared with a global directive Values are assigned to these symbols as follows text is assigned the first address
281. inker directives Section Number SectionName Page 1 5 Linker Command Files 7 21 224 The MEMORY Directive 7 8 The SECTIONS Directive 7 32 7 12 Default Allocation Algorithm 7 58 Introduction to Common Object File Format 2 13 How the Linker Handles Sections 2 4 1 Default Memory Allocation Figure 2 3 illustrates the process of linking two files Figure 2 3 Combining Input Sections to Form an Executable Object Module Pro file1 obj table_1 initialized named section u vars uninitialized namedsection In Figure 2 3 file1 o0bj and file2 0bj have been assembled to be used as linker input Each contains the text data and bss default sections in addition each contains named sections The executable output module shows the combined sections The linker combines file1 text with file2 text to form one text section then combines the data sections then the bss sections and finally places the named sections at the end The memory map shows how the sections are putinto memory by default the linker begins at address 080h and table 1 initialized named section u vars uninitialized namedsection EBD initialized named section Data Memory 4 LLL A pg reon igured 7 file1 bss file2 bss file1 U vars file2 U vars unused places the sections one after the other as shown 2 14
282. into TMS320C54x system memory and executed by the device listing file An output file created by the assembler that lists source state ments their line numbers and their effects on the SPC loader Adevicethatloads an executable module into TMS320C54x system memory Glossary macro A user defined routine that can be used as an instruction macro call The process of invoking a macro macro definition A block of source statements that define the name and the code that make up a macro macro expansion The source statements that are substituted for the macro call and are subsequently assembled macro library An archive library composed of macros Each file in the library must contain one macro its name must be the same as the macro name it defines and it must have an extension of asm magic number A COFF file header entry that identifies an object file as a module that can be executed by the TMS320C54x map file An output file created by the linker that shows the memory configuration section composition and section allocation as well as symbols and the addresses at which they were defined member The elements or variables of a structure union archive or enu meration memory map A map of target system memory space which is partitioned into functional blocks mnemonic An instruction name that the assembler translates into machine code model statement Instructions or assembler directives in a macro de
283. io uz Page width 100 characters TOR length 55 width 100 Assembler Directives 4 61 list nolist Syntax Description Example Start Stop Source Listing list nolist Two directives enable you to control the printing of the source listing DD The list directive allows the printing of the source listing The nolist directive suppresses the source listing output until a list directive is encountered The nolist directive can be used to reduce assembly time and the source listing size It can be used in macro defini tions to suppress the listing of the macro expansion The assembler does not print the list or nolist directives or the source state ments that appear after a nolist directive However it continues to increment the line counter You can nest the list nolist directives each nolist needs a matching list to restore the listing By default the source listing is printed to the listing file the assembler acts as if the list directive had been specified However if you don t request a listing file when you invoke the assembler the assembler ignores the list directive This example shows how the copy directive inserts source statements from another file The first time this directive is encountered the assembler lists the c
284. ion address is equal to the linker assigned section load address In a boot table the address field of the the hex conversion utility output file is not related to the section load addresses assigned by the linker The address fields of the boot table are simply offsets to the beginning of the table multi plied by the correction factor data width divided by memory width The section load addresses assigned by the linker will be encoded into the boot table along with the size of the section and the data contained within the section These addresses will be used to store the data into memory during the boot load process The beginning of the boot table defaults to the linked load address of the first bootable section in the COFF input file unless you use one of the following mechanisms listed here from low to high priority Higher priority mechanisms override the values set by low priority options in an overlapping range Controlling the ROM Device Address 1 The ROM origin specified in the ROMS directive The hex conversion utility places the boot table at the origin of the first memory range in a ROMS directive 2 The bootorg option The hex conversion utility places the boot table at the address specified by the bootorg option if you select boot loading from memory 3 The bootorg option The hex conversion utility places the boot table at the address specified by the bootorg option if you select boot loading from memory Nei
285. ion of the object code All machine instructions and directives use this field to list object code This field also indicates the relocation type by appending one of the following characters to the end of the field undefined external reference text relocatable data relocatable sect relocatable bss usect relocatable complex relocation expression Field 4 Source Statement Field This field contains the characters of the source statement as they were scanned by the assembler Spacing in this field is determined by the spacing in the source statement Example 3 4 shows an assembler listing with each of the four fields identified Example 3 4 Assembler Listing a Mnemonic example Source Listings co 10 01 CO PO I COO O0 OO 1 OY O1 4S CO PO ES 20 21 22 23 24 25 26 27 28 29 30 31 32 000000 000000 000001 000002 000003 000004 000005 000006 000007 000000 000000 000001 000002 000003 000004 000005 000006 000007 000008 000008 000009 E 00000a 00000b E 00000c F073 0008 F073 0000 F073 0000 F073 0000 F073 0000 F073 0000 F073 0000 F073 0000 global RESET INTO INT1 INT2 global TINT RINT XINT USER global ISRO ISR1 ISR2 global time rcv xmt proc initmac macro initialize macro SSBX OVM disable oflow LD 40 DP dp 0 LD 7 ARP arp ar7 LD 037h A acc 03f
286. irective without changing the output In simple cases like this you can use eval and asg interchangeably However you must use eval if you want to calculate a value from an expression While asg only assigns a character string to a substitution symbol the eval directive evaluates an expression and assigns the character string equivalent to a substitution symbol 5 3 2 Built In Substitution Symbol Functions The following built in substitution symbol functions enable you to make decisions based on the string value of substitution symbols These functions always return a value and they can be used in expressions Built in substitution symbol functions are especially useful in conditional assembly expressions Parameters to these functions are substitution symbols or character string constants Macro Parameters Substitution Symbols In the function definitions shown in Table 5 1 aand bare parameters that rep resent substitution symbols or character string constants The term string re fers to the string value of the parameter The symbol ch represents a character constant Table 5 1 Functions and Return Values Function Return Value symlen a length of string a symcmp ab lt Oifa lt b Oifa b gt O0ifa gt b firstch a ch index of the first occurrence of character constant ch in string a lastch a ch index of the last occurrence of character constant chin string a isdefed a 1 if string ais defined in the symbol tabl
287. is assigned to the first file specified by a include directive B is assigned to the second file etc A blank in this column indicates that the symbol was never used Cross Reference Lister Description 9 5 Cross Reference Listing Example Table 9 1 Symbol Attributes Character Meaning Symbol defined in a text section Symbol defined in a data section Symbol defined in a sect section Symbol defined in a bss or usect section Symbol defined in a reg section Chapter 10 Hex Conversion Utility Description The TMS320C54x assembler and linker create object files that are in common object file format COFF COFF is a binary object file format that encourages modular programming and provides more powerful and flexible methods for managing code segments and target system memory Most EPROM programmers do not accept COFF object files as input The hex conversion utility converts a COFF object file into one of several standard ASCII hexadecimal formats suitable for loading into an EPROM programmer The utility is also useful in other applications requiring hexadecimal conversion of a COFF object file for example when using debuggers and loaders This utility also supports the on chip boot loader built into the target device automating the code creation process for the C54x The hex conversion utility can produce these output file formats ASCIl Hex supporting 16 bit addresses Extended Tektronix Tektronix Intel MCS
288. is section contains technical data about the internal format and structure of COFF object files It discusses symbolic debugging directives that the C C compiler uses Finally it includes hex conversion utility examples assembler and linker error messages and a glossary This document uses the following conventions Program listings program examples and interactive displays appear in a special typeface Examples use a bold version of the special typeface for emphasis interactive displays use a bold version ofthe special typeface to distinguish commands that you enter from items that the system displays such as prompts command output error messages etc Here is a sample program listing 2 0001 2f x byte 47 3 0002 32 Zz byte 50 4 0003 text In syntax descriptions the instruction command or directive is in a bold typeface font and parameters are in an italic typeface Portions of a syntax that are in bold should be entered as shown portions of a syntax that are in italics describe the type of information that should be entered Here is an example of command line syntax abs500 filename abs500 is a command The command invokes the absolute lister and has one parameter indicated by filename When you invoke the absolute lister you supply the name of the file that the absolute lister uses as input Square brackets and identify an optional parameter If you use an optional parameter you speci
289. istency of load and run allocations specified for unions groups and sections The following rules are used m Run allocations are only allowed for top level sections groups or unions sections groups or unions that are not nested under any other groups or unions The linker uses the run address of the top level structure to compute the run addresses of the components within groups and unions As discussed in Section 7 10 1 the linker does not accept a load allocation for UNIONS As discussed in Section 7 10 1 the linker does not accept a load allocation for uninitialized sections In most cases you must provide a load allocation for an initialized section However the linker does not accept a load allocation for an initialized sec tion that is located within a group that already defines a load allocator As a shortcut you can specify a load allocation for an entire group to de termine the load allocations for every initialized section or subgroup nested within the group However a load allocation is accepted for an entire group only if all of the following conditions are true B The group is initialized i e it has at least one initialized member B The groupis not nested inside another group that has a load allocator B The group does not contain a union containing initialized sections If the group contains a union with initialized sections it is necessary to specify the load allocation for each initialized sectio
290. ive is used to define macros You can define a macro anywhere in your program but you must define the macro before you can use it Macros can be defined at the beginning of a source file in an include copy file or in a macro library macname names the macro You must place the name in the source statement s label field macro identifies the source statement as the first line of a macro definition You must place macro in the op code field parameters are optional substitution symbols that appear as operands for the macro directive model statements are instructions or assembler directives that are ex ecuted each time the macro is called macro directives are used to control macro expansion endm terminates the macro definition Macros are explained in further detail in Chapter 5 Macro Language Assembler Directives 4 67 mlib Define Macro Library Syntax Description mlib filename The mlib directive provides the assembler with the name of a macro library A macro library is a collection of files that contain macro definitions These files are bound into a single file called a library or archive by the archiver Each member of a macro library may contain one macro definition that corresponds to the name of the file Macro library members must be source files not object files The filename of a macro library member must be the same as the macro name and its extension must be asm The file
291. ive library into a specific output section The syntax for such an allocation is SECTIONS output sec 1 lib_name lt obj1 obj2 objn sec name In this syntax the ib_name is the archive library The is optional since the library search algorithm is always used to search for the archive For more in formation on the option see Section 7 4 9 Alter the Library Search Algo rithm on page 7 13 Brackets lt gt are used to specify the archive member s The brackets may contain one or more object files separated by a space The sec_name is the archive section to be allocated For example SECTIONS boot gt BOOTL 1 rts lib lt boot obj exit obj strcpy obj text rts gt BOOT2 rts lib text text gt RAM text In the specification above the text sections of boot obj exit obj and strcpy obj from rts lib will be placed in the boot section The remainder of the text sections from rts lib will be placed in the rts section All other unallocated text sections will be placed in the text section Linker Description 7 43 Specifying a Section s Runtime Address 7 9 Specifying a Section s Runtime Address 7 9 1 7 44 At times you may want to load code into one area of memory and run it in another For example you may have performance critical code in a ROM based system The code must be loaded into ROM but it would run faster in RAM
292. k or all remarks A remark is an informational assembler message that is less severe than a warning The remark directive re enables the remark s previously suppressed by horemark The version directive determines the processor for which instructions are being built Each C54x device has its own value Assembler Directives 4 23 Miscellaneous Directives These three directives enable you to define your own error and warning messages L The emsg directive sends error messages to the standard output device The emsg directive generates errors in the same manner as the assembler incrementing the error count and preventing the assembler from producing an object file The mmsg directive sends assembly time messages to the standard output device The mmsg directive functions in the same manner as the emsg and wmsg directives but does not increment the error count or the warning count It does not affect the creation of the object file The wmsg directive sends warning messages to the standard output device The wmsg directive functions in the same manner as the emsg directive but increments the warning count rather than the error count It does not affect the creation of the object file Directives Reference 4 11 Directives Reference The remainder of this chapter is a reference Generally the directives are organized alphabetically one directive per page Related directives such as if else endif however are pr
293. k Ck Pk Pk kx o 24 Assemble into text ER 25 occ ck ck ck ck ck ck ck ck ck 0k 0k 0k 0k 0k 00k kk kk kk ck ck ck ck ck ck ck ck Ck Ck kx KKK 26 000001 text 27 000001 000c ADD Table A 28 29 kk cock ck ck ck ck ck ck ck ck 0k 0k 0k 0k 0k 0k 0k kk kk ck ck ko KKK ck ck Ck Ck kx KKK 30 Resume assembling into the data WE 31 section at address OFh ER 22 33 00000f data Assembler Directives 4 39 double Idouble Initialize Double Precision Floating Point Value Syntax double value value Idouble value value Description The double and Idouble directives place the IEEE single precision floating point representation of one or more floating point values into the current section Each value must be a floating point constant or a symbol that has been equated to a floating point constant Each constant is converted to a floating point value in IEEE single precision 32 bit format Floating point constants are aligned on a word boundary The value consists of three fields Field Meaning s A 1 bit sign field e An 8 bit biased exponent f A 23 bit fraction The value is stored most significant word first least significant word second in the following format 31 30 23 22 0 When you use double or ldouble in a struct endstruct sequence the direc
294. l absolute value The second statement is illegal because the sum of two relocatable symbols is not an absolute value LD intern 1 intern 2 d xtern 1 B Legal LD intern 1 intern 2 xtern 1 B Illegal Lj Example 4 An external symbol s placement is important to expression evaluation Although the statement below is similar to the first statement in the previous example itis illegal because of left to right operator precedence the assembler attempts to add intern_1 to extern_1 LD intern 1 d xtern 1 intern 2 B Illegal Assembler Description 3 29 Built in Functions 3 10 Built in Functions The assembler supports built in functions for conversions and various math computations Table 3 3 describes the built in functions Note that expr must be a constant value See Table 5 1 for a description of the assembler s non mathematical built in functions Table 3 3 Assembler Built In Math Functions 3 30 Function acos expr asin expr atan expr atan2 expr ceil expr cosh expr cos expr cvf expr cvi expr exp expr fabs expr floor expr fmod expr1 expr2 int expr Idexp expr1 expr2 log10 expr log expr max expr1 expr2 min expr1 expr2 Description returns the arc cosine of expr as a floating point value returns the arc sine of expr as a floating point value returns the arc tangent of expr as a floating point value returns the arc tangent
295. l obj f2 0bj 1 r lib 1 lib2 1lib ld and ld2 setenv C DIR l1d 1d2 1nk500 fl obj f2 0bj l r lib 1 lib2 1lib Linker Description 7 15 Linker Options Note that the environment variable remains set until you reboot the system or reset the variable by entering Operating System Enter DOS set C DIR UNIX unsetenv C DIR The assembler uses an environment variable named A DIR to name alterna tive directories that contain copy include files or macro libraries If C DIR is not set the linker will search for object libraries in the directories named with A DIR Section 7 6 Object Libraries on page 7 25 contains more information about object libraries 7 4 10 Disable Conditional Linking j Option The j option disables conditional linking that has been set up with the assembler clink directive By default all sections are unconditionally linked 7 4 11 Ignore Alignment Flags k Option The k option forces the linker to ignore any SECTIONS directive alignment specifications For more information on the SECTIONS directive see Section 7 8 The SECTIONS Directive 7 4 12 Create a Map File m filename Option 7 16 The m option creates a linker map listing and puts it in filename The syntax for the m option is m filename The linker map describes DD Memory configuration Input and output section allocation The addresses of external symbols after they have been relocated The map file
296. language code global array bss array 50 0 0 Sym _array _array 244 2 800 5 10 global _ptr bss _ptr 1 0 0 Sym pt ptr 21 2 15 global str bss str 2 070 Sym Str SU 9 2 325 8 global ext bss _ext 1 0 0 Sym _ext _ext 4 2 16 Symbolic Debugging Directives B 11 Appendix C Hex Conversion Utility Examples The flexible hex conversion utility offers many options and capabilities Once you understand the proper ways to configure the EPROM system and the requirements of the EPROM programmer you will find that converting a file for a specific application is easy Topic Page C 1 Base Code for the Examples esee E 2 C 2 Example 1 Building a Hex Command File for Two 8 Bit EPROMS enant sessio cavasu etis ce ae Vue c 3 C 3 Example 2 Avoiding Holes With Multiple Sections C 4 Example 3 Generating a Boot Table C 10 C 5 Example 4 Generating a Boot Table for LP Core Devices C 1 Base Code for the Examples C 1 Base Code for the Examples The three major examples in this appendix show how to develop a hex com mand file for multiple EPROM memory systems avoid holes and generate a boot table The first two examples use the assembly code shown in Example C 1 Example C 1 Assembly Code for Hex Conversion Utility Examples Dk ck ck ck ck ck ck ck Sk ck ck 0k ck kk ck Ck ck ck 0k ck ck ck ck Ck ck ck ck ck Ck ck ck ck ck ck
297. late definitions The exp intermediate file that the assembler pro duces is deleted after the translation is complete Translation Modes Example 11 2 Expansion Mode a Source code file asm asg ARO sym mymac macro parml parm2 LD parml parm2 ADD sym 5 parm2 B endm mymac sym A b Intermediate code file exp after preprocessing before translation asg ARO sym mymac macro parml parm2 LD parml parm2 ADD sym 5 parm2 B endm mymac sym A LD ARO A ADD ARO 5 A B kk ck Ck KKK KKK KKK KKK KKK KKK KKK KKK KK KKK c Converted code file cnv after translation Dk ck ck ck ck ck kk KKK kk ck Ck ck ck kk ck ck ck KKK KKK KKK K asg ARO sym mymac macro parml parm2 LD parml parm2 ADD sym 5 parm2 B endm mymac sym A A ARO B A ARO lt lt 5 Mnemonic to Algebraic Translator Description 11 7 How the Translator Works With Macros 11 5 How the Translator
298. les between sections in a range The value must be a decimal octal or hexadecimal constant with a width equal to the target width Any value you specify here overrides the fill option When using fill you must also use the image command line option See subsection 10 8 2 Specifying a Fill Value on page 10 27 Hex Conversion Utility Description 10 17 The ROMS Directive files identifies the names of the output files that correspond to this range Enclose the list of names in curly braces and order them from least significantto most significant output file The number of file names should equal the number of output files that the range will generate To calculate the number of output files refer to Section 10 4 4 HOM Width on page 10 11 The utility warns you if you list too many or too few file names Unless you are using the image option all of the parameters defining a range are optional the commas and equals signs are also optional A range with no origin or length defines the entire address space In image mode an origin and length are required for all ranges Ranges on the same page must not overlap and must be listed in order of ascending address 10 5 1 When to Use the ROMS Directive 10 18 If you do notuse a ROMS directive the utility defines a default memory config uration that includes two address spaces PAGE 0 and PAGE 1 Each address space contains a single address range PAGE 0 contains a default ran
299. lid shift value Must add ARO to destination Must subtract ARO from destination Only labels and comments may begin in first column Operand must be the A accumulator Operand must be the B accumulator Section is not defined Shift value must be 16 Syntax error Operand nnn The accumulator arguments must be the same The accumulator arguments must not be the same The dst accumulator arguments must be the same The dst src1 arguments must be the same The smem operands must be the same Unexpected parallel instruction delimiters Description These are errors about invalid operands The instruction parameter or other operand specified was not recognized Action Correct the source per the error message text Assembler Error Messages Absolute well defined integer value expected Expecting accumulator A or B Expecting ASM or shift value Expecting dual memory addressing Identifier expected Identifier operand expected Illegal character argument specified Illegal combination of Smem operands Illegal floating point expression Illegal operand Illegal shift operation Illegal structure reference Incorrect bit symbol for specified status register Invalid data size for relocation Invalid float constant specified Invalid identifier sym specified Invalid macro parameter specified Invalid operand char Must add to the destination operand No parameters available for macro arguments Not expecting direct operand op Not exp
300. lied for a section memory attributes redefined for Description More than one set of memory attributes is supplied for an out put section memory types and on page overlap Description Memory ranges on the same page overlap Action If you are using a linker command file check that MEMORY and SECTIONS directives allow enough room to ensure that no sections are being placed in unconfigured memory missing filename on 1 use filename Description No filename operand is supplied for the lowercase L option misuse of DOT symbol in assignment instruction Description The symbol is used in an assignment statement that is out side the SECTIONS directive no allocation allowed for uninitialized UNION member Description A load address was supplied for an uninitialized section in a union An uninitialized section in a union gets its run address from the UNION statement and has no load address so no load allocation is valid for the member Linker Error Messages no allocation allowed with a GROUP allocation for section ignored Description A section in a group was specified for individual allocation The entire group is treated as one unit so the group may be aligned or bound to an address but the sections making up the group cannot be handled individually no input files Description No COFF files were supplied The linker cannot operate with out at least one input COFF file
301. line or in a linker command file Options are discussed in Section 7 4 Linker Options on page 7 6 filenames can be object files linker command files or archive libraries The default extension for all input files is obj any other exten sion must be explicitly specified The linker can determine whether the input file is an object or ASCII file that contains linker commands The default output filename is a out There are three methods for invoking the linker Specify options and filenames on the command line This example links two files file1 obj and file2 obj and creates an output module named link out 1nk500 filel obj file2 0bj o link out Enter the Ink500 command with no filenames and no options the linker prompts for them Command files Object files 0bj Output file a out Options B For command files enter one or more command filenames B For object files enter one or more object filenames The default exten sion is obj Separate the filenames with spaces or commas if the last character is a comma the linker prompts for an additional line of object filenames B The output file is the name of the linker output module This overrides any o options entered with any of the other prompts If there are no o options and you do not answer this prompt the linker creates an object file with a default filename of a out B The options prompt is for additional options although you can also en
302. list options macro listing page eject page length page width substitution symbols 4 83 suppressing 4 62 tab size 4 70 Index little endian ordering 10 14 Ink500 command load address of a section described 7 44 44 referring to z a label load linker keyword PIES ae loader defined F 4 loading a program local labels 8 22 logical operators long directive 14 13 compatibility with C1x C2x C2xx C5x limiting listing with option directive 4 17 4 76 loop directive 4 20 4 66 use in macros m linker option 7 16 m1 hex conversion utility option m2 hex conversion utility option m3 hex conversion utility option macro comments conditional Sy 5 15 to 5 16 defined F 5 defining 5 3 described directives summary 5 25 disabling macro expansion listing 4 17 4 76 formatting the output listing b labels to 5 18 libraries 5 14 mlib assembler directive mlist assembler directive 4 70 nested parameters 5 6lto 5 13 producing messages recursive b 22 to b 24 substitution symbols 5 6 to 5 13 using a macro macro call defined macro definition defined macro directive 4 67 summary table macro expansion defined macro library defined F 5 magic number defined Index 9 Index main malloc 7 12 7 73 map file creating defined example math functions member defined member symbolic debugging directive memory allocation defa
303. lled with the fill value from the ROMS directive with the value specified with the fill option or with the default value of 0 10 5 2 An Example of the ROMS Directive The ROMS directive in Example 10 1 shows how 16K words of 16 bit memory could be partitioned for four 8K x 8 bit EPROMs Example 10 1 A ROMS Directive Example infile out image memwidth 16 ROMS EPROM1 org 04000h len 02000h romwidth 8 files rom4000 b0 rom4000 b1 EPROM2 org 06000h len 02000h romwidth 8 fill OFFh files rom6000 b0 rom6000 b1 In this example EPROM 1 defines the address range from 4000h through 5FFFh The range contains the following sections This section Has this range text 4000h through 487Fh data 5B80H through SFFFh The rest of the range is filled with Oh the default fill value The data from this range is converted into two output files L rom4000 b0 contains bits 0 through 7 J rom4000 b1 contains bits 8 through 15 EPROM2 defines the address range from 6000h through 7FFFh The range contains the following sections This section Has this range data 6000h through 633Fh table 6700h through 7C7Fh Hex Conversion Utility Description 10 19 The ROMS Directive The rest of the range is filled with OFFh from the specified fill value The data from this range is converted into two output files rom6000 b0 contains bits 0 through 7 J rom6000 b1 contains bits 8 thr
304. llowed in top most structure definition Access point has already been defined Open block s at EOF Description These are warnings about problems with structure defini tions Action Correct the source per the error message text A branch to an empty label just inside the loop closing brace is a branch out of the loop Far mode valid only for C548 First instruction following XC must be a 1 word instruction Open branch delay slot at end of section Power of 2 required next larger power of 2 assumed Second instruction following XC must be a 1 word instruction Section name absolute address set to 0 Section name is larger than 64K Value truncated to byte size Description These are general warnings Action Correct the source per the warning message text Appendix E Linker Error Messages This appendix lists the the linker error messages in alphabetical order accord ingto the error message In these listings the symbol represents the name of an object that the linker is attempting to interact with when an error occurs absolute symbol being redefined Description An absolute symbol cannot be redefined Action Check the syntax of all expressions and check the input di rectives for accuracy adding name to multiple output sections Description The input section is mentioned twice in the SECTIONS direc tive ALIGN illegal in this context Description Alignment of a symbol is performed outside of a SECTIO
305. llowing syntax for the MEMORY directive MEMORY PAGE 0 name 1 attr origin constant length constant PAGE n name n attr origin constant length constant Each page is introduced by the keyword PAGE and a page number followed by a colon and a list of memory ranges the page contains Bold portions must be entered as shown Memory ranges are specified in the normal way You can define up to 255 overlay pages Because each page represents a completely independent address space memory ranges on different pages can have the same name Configured memory on any page can overlap configured memory on any other page Within a single page however all memory ranges must have unique names and must not overlap Overlay Pages Memory ranges listed outside the scope of a PAGE specification default to PAGE 0 Consider the following example MEMORY PAGE ROM RAM XROM XRAM org EPROM org i org org org Oh 1000h 2000h Oh 2000h len len len len len 1000h 1000h OE000h 1000h 0E000nh The memory ranges ROM EPROM and RAM are all on PAGE 0 since no page is specified XROM and XRAM are on PAGE 1 Note that XROM on PAGE 1 overlays ROM on PAGE 0 and XRAM on PAGE 1 overlays RAM on PAGE 0 In the output link map obtained with the m linker option the listing of the memory model is keyed by pages This provides an easy method of verifying that you specified the
306. load affects the load address until the keyword run is seen after which everything affects the run address The load and run allocations are completely independent so any qualification of one such as alignment has no effect on the other You may also specify run first then load Use parentheses to improve readability Specifying a Section s Runtime Address The examples below specify load and run addresses data load ROM align 32 run RAM align applies only to load data load ROM align 32 run RAM identical to previous example RAM align 32 align 16 data run load align 32 in RAM for run align 16 anywhere for load 7 9 2 Uninitialized Sections Uninitialized sections such as bss are not loaded so their only significant address is the run address The linker allocates uninitialized sections only once if you specify both run and load addresses the linker warns you and ignores the load address Otherwise if you specify only one address the linker treats it as a run address regardless of whether you call it load or run The example below specifies load and run addresses for an uninitialized section bss load 0x1000 run RAM A warning is issued load is ignored and space is allocated in RAM All of the following examples have the same effect The bss section is allocated in RAM bss load RAM bss run RAM bss RAM 7 9 3 Referring to the Load Address by Using the label Dire
307. load as a union text 2 load Since the text sections contain data they cannot oad as a union although they can be run as a union Therefore each requires its own load address If you fail to provide a load allocation for an initialized section within a union the linker issues a warning and allocates load space anywhere it fits in configured memory Uninitialized sections are not loaded and do not require load addresses The UNION statement applies only to allocation of run addresses so it is redundant to specify a load address for the union itself For purposes of allocation the union is treated as an uninitialized section any one allocation specified is considered a run address and if both are specified the linker issues a warning and ignores the load address The alignment and block attributes of a union are the maximum alignment and block attributes of any of its members Linker Description 7 49 Using UNION and GROUP Statements A ye 6 a ep cal Note UNION and Overlay Page Are Not the Same The UNION capability and the overlay page capability see Section 7 11 Overlay Pages on page 7 53 may sound similar because they both deal with overlays They are in fact quite different UNION allows multiple sections to be overlaid within the same memory space Overlay pages on the other hand define multiple memory spaces It is possible to use the page facility
308. lopment FIOW Peer D 7 3 73 Invokitnig the Pinker sais a eden cs Mc EAM UE ELM 7 4 Linker Options REI e yee xA 75 Linker command Files 59 neee EORR UIS ETEE T4 Object libraries eae e E a a 7 25 77 The MEMORY Directive e meae ome IR IU Uere 7 8 The SECTIONS Directive a lt an aa e aaa a o ees 7 32 7 9 Specifying a Section s Runtime Address 7 10 Using UNION and GROUP Statements pp 7 41 Overlay Pages 7 53 7 12 Default Allocation Algorithm cence eee 7 13 Special Section Types DSECT COPY and NOLOAD 7 14 Assigning Symbols at Link Time seeeeeeeeee 7 45 Creating and Filling HoleS se rece ee en TET PEE 7 16 Partial Incremental Linking os Tag inking Ci Cer Code ea ce cec e e Pe der 7 18 EInker Exampl8 xc toot sione ecu oM ean enan Linker Overview 7 1 Linker Overview The TMS320C54x linker allows you to configure system memory by allocating output sections efficiently into the memory map As the linker combines object files it performs the following tasks Allocates sections into the target system s configured memory Relocates symbols and sections to assign them to final addresses J Resolves undefined external references between input files The linker command language controls memory configuration output section definition and address binding The language supports expression assign ment and evaluation You configure s
309. ly a specific starting address for an output section by following the section name with an address text 0x1000 This example specifies that the text section must begin at word location 1000h The binding address must be a 16 bit constant Output sections can be bound anywhere in configured memory assuming there is enough space but they cannot overlap If there is not enough space to bind a section to a specified address the linker issues an error message Note Binding and Alignment or Named Memory are Incompatible You cannot bind a section to an address if you use alignment or named memory If you try to do so the linker issues an error message LLLLLLLLLL L LL 3 The SECTIONS Directive 7 8 3 2 Named memory You can allocate a section into a memory range that is defined by the MEMORY directive This example names ranges and links sections into them MEMORY ROM RIX origin 0CO0O0h length 1000h RAM RWIX origin 0080h length 1000h SECTIONS text gt ROM data ALIGN 128 gt RAM bss gt RAM In this example the linker places text into the area called ROM The data and bss output sections are allocated into RAM You can align a section within a named memory range the data section is aligned on a 128 word boundary within the RAM range Similarly you can link a section into an area of memory that has particular attributes
310. m If numis not specified all remarks will be suppressed A remark is an informa tional assembler message that is less severe than a warning This directive is equivalent to using the r num assembler option The remark directive re enables the remark s previously suppressed Assembler Directives 4 75 Option Select Listing Options Syntax option option list Description The option directive selects several options for the assembler output listing Option list is a list of options separated by vertical lines each option selects a listing feature These are valid options limits the listing of byte directives to one line limits the listing of long directives to one line turns off macro expansions in the listing resets the B M T and W options limits the listing of string directives to one line limits the listing of word directives to one line produces a symbol cross reference listing You can also obtain a cross reference listing by invoking the assembler with the x option x z4amzru Options are not case sensitive Example Select Listing Options String directives to one line each Nu BWNE 7 8 9 10 1 12 13 14 15 16 18 19 000000 000004 000008 00000a 00001c 00001d 00001e 000020 000021 000022 000023 000024 000025 000026 000027 000028 000029 00002a 00002b 00002c 00002d 00002e 00002 f 000030 000031 000032 000033 000034 000035 000036 00003
311. m counter relational operators 3 27 See also SPC relocatable defined output module SECTIONS symbols hex conversion utility directive 10 22 to 10 23 relocation linker directive at runtime alignment V 34 capabilities 78 to 7 9 allocation l 35 to 7 43 defined Ra sections allocation using multiple memory 6 to ranges J 40 structuring norman A to to A 11 binding 36 remark directive 4 23 4 75 blocking 7 38 remarks Kanpissein default allocation 58 to 60 TUPP default model g reserved words linker 7 24 described resetting local labels fill value Index 12 SECTIONS linker directive continued GROUP input sections 38 to 7 40 label directive load allocation memory 7 37 to 7 76 overlay pages l 53 to 7 57 reserved words run allocation section specifications 7 33 section type V 33 specifying E s RU splitting of output sections syntax uninitialized sections UNION F 48 to 7 52 use with MEMORY directive 7 2 sections allocation 7 5 HESS ET COFF p 3 to 2 4 creating your own defined in the linker SECTIONS directive 7 33 initialized named 2 8 overlaying with UNION directive 7 48 to 7 50 relocation 2 16 to special types specifications specifying a runtime address E radi e specifying M Sols sections uninitialized 2 5 to 2 6 initializing T specifying a run address set directive Setsect directive 8 8 Setsym directive Shor
312. m memory 32 words of RAM at address 60h in data memory and 4K words at address 80h in data memory Example 7 3 The MEMORY Directive Sample command file with MEMORY directive X KR KK RR RA ECC KCk kCk kc k k k kc k k k Ck ck k ck ck ck ck ck ck ck ck ck sk sk sk e ke e ke x e x x f filel obj file2 0bj Input files o prog out Options md MEMORY MEMORY directive PAGE 0 r ROM origin C00h 4 length 1000h 4 PAGE options PAGE 1 f SCRATCH origin 60h 74 length 20h 4 m ONCHIP origin 80h 4 length 1000h 4 names origins lengths The MEMORY Directive The general syntax for the MEMORY directive is MEMORY PAGE 0 name 1 attr origin constant length constant PAGE n name n attr origin constant length constant PAGE name attr origin identifies a memory space You can specify up to 255 pages depending on your configuration usually PAGE 0 specifies program memory and PAGE 1 specifies data memory If you do not specify a PAGE the linker acts as if you specified PAGE 0 Each PAGE represents a completely independent address space Configured memory on PAGE 0 can overlap configured memory on PAGE 1 Names a memory range A
313. mat of the i option is as follows asm500 ipathname source filename Each i option names one pathname There is no limit to the number of paths that you can specify In assembly source you can use the copy include or mlib directive without specifying path information If the assembler doesn t Naming Alternate Files and Directories for Assembler Input find the file in the directory that contains the current source file it searches the paths designated by the i options For example assume that a file called source asm is in the current directory source asm contains the following directive statement COPY copy asm Assume that the file is stored in the following directory Windows c tools files copy asm UNIX tools files copy asm Operating System Enter Windows asm500 ic tools files source asm UNIX asm500 i tools files source asm The assembler first searches for copy asm in the current directory because source asm is in the current directory Then the assembler searches in the directory named with the i option 3 4 2 Using Environment Variables C54X A DIR and A DIR An environment variable is a system symbol that you define and assign a string to The assembler uses the environment variables C54X A DIR and A DIR to name alternate directories that contain copy include files or macro libraries The assembler looks for the C54X A DIR environment variable first and then reads and processe
314. mber information They occupy no actual space in the object file Therefore the number of relocation entries the number of line number en tries and the file pointers are 0 for an uninitialized section The header of an uninitialized section simply tells the linker how much space for variables it should reserve in the memory map Common Object File Format A 9 Structuring Relocation Information A 5 Structuring Relocation Information A COFF object file has one relocation entry for each relocatable reference The assembler automatically generates relocation entries The linker reads the relocation entries as it reads each input section and performs relocation The relocation entries determine how references within each input section are treated COFF file relocation information entries use the 12 byte format shown in Table A 7 Table A 7 Relocation Entry Contents Byte Number Type Description 0 3 Long integer Virtual address of the reference 4 7 Unsigned long integer Symbol table index 8 9 Unsigned short integer For COFF1 files Reserved For COFF2 files Additional byte used for extended address calculations 10 11 Unsigned short integer Relocation type see Table A 8 The virtual address is the symbol s address in the current section before relo cation it specifies where a relocation must occur This is the address of the field in the object code that must be patched Following is an example of code that generates a relocatio
315. mbler Directives 4 95 USect Reserve Uninitialized Space For more information about COFF sections see Chapter 2 Introduction to Common Object File Format Example This example uses the usect directive to define two uninitialized named sec tions var1 and var2 The symbol ptr points to the first word reserved in the var1 section The symbol array points to the first word in a block of 100 words reserved in var1 and dflag points to the first word in a block of 50 words in var1 The symbol vec points to the first word reserved in the var2 section Figure 4 7 on page 4 97 shows how this example reserves space in two unini tialized sections var1 and var2 1 ck ck ck ck ck ck ck KKK ok ck ck ck Ck 0k ck ck ck ck ck ck ck ck ck ck ck kk ck kk kk kv Sk k ko ko ko ok 2 VN Assemble into text section EK 3 4 000000 text 5 000000 E803 LD 03h A 6 7 8 um Reserve 1 word in varl To 9 ck oko ck ck ck ck ck KKK KK KK KKK KKK ck ck ck ck ck ck KK KAKA KKK KKK KKK 10 000000 ptr usect v ri 1 Ti 12
316. mbolic debugging purposes it is sometimes useful to have entries in the symbol table for each symbol in a program To accomplish this invoke the assembler with the s option Chapter 3 Assembler Description The assembler translates assembly language source files into machine language object files These files are in common object file format COFF which is discussed in Chapter 2 Introduction to Common Object File Format and Appendix A Common Object File Format Source files can contain the following assembly language elements Assembler directives described in Chapter 4 Macro directives described in Chapter 5 Assembly language instructions described in the TMS320C54x Instruction Set Reference Guides Topic Page 3 Assembler Overview aa e o ec ee IN Tct Ur iae euer TIE 5 2 3 2 Assembler Development Flow eeseeeeeeees B 3 3 3 Invoking the Assembler ss B 4 3 4 Naming Alternate Files and Directories for Assembler Input 3 5 Source Statement Format esses nnne 3 6 Constantsz 39cm TE ITE B 15 3 7 E Character Strings sancsoanepscesssossossnuesnnsocanesuacauscre O M E MEC GH EXPiessions EE E TETTE B 25 3 10 BuiltiniFunctonsi er reco e hee eee LAE 3 11 Loading Values into Extended Program Memory 5 32 3 12 Source Listinge rrer neinke eneren a B 33 3 439 Cross Heference Listing 1 e e e A 3 37 3 1 Assembler Overview 3 4 Assembler Overview This two pa
317. me therefore the hex conversion utility creates a single output file The number of output files is determined by the ratio of memwidth to romwidth Example C 17 shows the map file cb4xlp mxp resulting from executing the command file in Example C 16 which includes the map option C 22 Example 4 Generating a Boot Table for LP Core Devices Example C 17 Map File Resulting From the Command File in Example C 16 Ck Ck ck ck Ck ck ck ck ck KK KKK ok Ck Ck ck Ck Sk ck Ck ck ck ck ck ck Sk ck Ck ck ck kk KKK ck kk kk KKK KKK KKK KKK TMS320C54x COFF Hex Converter Version x xx Sat Sep 21 17 01 13 2001 INPUT FILE NAME c54xlp out OUTPUT FORMAT Intel PHYSICAL MEMORY PARAMETERS Default data width 16 Default memory width 8 MS LS Default output width 8 BOOT LOADER PARAMETERS Table Address 0000 PAGE 0 OUTPUT TRANSLATION MAP 00000000 0001ffff Page 0 Memory Width 8 ROM Width 8 ROM OUTPUT FILES c54xlp hex b0 b7 CONTENTS 00000000 00000109 BOOT TABLE text dest 00001400 size 0000006d width 00000002 cinit dest 0000146d size 0000000d width 00000002 The hex conversion utility output file cb4xlp hex resulting from
318. memory model correctly Also the listing of output sections has a PAGE column that identifies the memory space into which each section will be loaded Linker Description 7 57 Default Allocation Algorithm 7 12 Default Allocation Algorithm The MEMORY and SECTIONS directives provide flexible methods for building combining and allocating sections However any memory locations or sections that you choose notto specify must still be handled by the linker The linker uses default algorithms to build and allocate sections within the specifications you supply Subsections 7 12 1 Allocation Algorithm and 7 12 2 General Rules for Output Sections describe default allocation 7 12 1 Allocation Algorithm If you do not use the MEMORY and SECTIONS directives the linker allocates output sections as though the following definitions are specified Example 7 13 Default Allocation for TMS320C54x Devices MEMORY PAGE 0 PROG origin 0x0080 length OxFF00 PAGE 1 DATA origin 0x0080 length OxFF80 SECTIONS text PAGE 0 data PAGE 0 Qrnats PAGE 0 cflag option only bss PAGE 1 All text input sections are concatenated to form a text output section in the executable output file and all data input sections are combined to form a data output section The text and data sections are allocated into configured memory on PAGE 0 which is the program memory space All bss sections are com
319. memory name may be one to 64 char acters valid characters include A Z a z and The names have no special significance to the linker they simply identify memory ranges Memory range names are internal to the linker and are not retained in the output file or in the symbol table Memory ranges on separate pages can have the same name with in a page however all memory ranges must have unique names and must not overlap Specifies one to four attributes associated with the named range Attributes are optional when used they must be enclosed in parentheses Attributes restrict the allocation of output sections into certain memory ranges If you do not use any attributes you can allocate any output section into any range with no restrictions Any memory for which no attributes are specified including all memory in the default model has all four attributes Valid attributes include R specifies that the memory can be read W specifies that the memory can be written to X specifies that the memory can contain executable code l specifies that the memory can be initialized Specifies the starting address of a memory range enter as origin org or o The value specified in words is a 16 bit constant and may be decimal octal or hexadecimal Linker Description 7 29 The MEMORY Directive length Specifies the length of a memory range enter as length len or l The value specified in words is a 16 bit constant and may be deci
320. menting Macro for zero accumulators incr macro decr macro ADD 1 A SUB A A ADD 1 B SUB B B endm endm Use the archiver to create a macro library ar500 a mac incr asm decr asm Now you can use the mlib directive to reference the macro library and define the incr and decr macros al mlib mac lib 2 000000 decr Macro call 1 000000 F420 SUB A A 1 000001 F720 SUB B B 3 000002 incr Macro call 1 000002 F000 ADD 1 A 000003 0001 T 000004 F300 ADD 1 B 000005 0001 Assembler Directives 4 69 mlist mnolist Syntax Description Example 4 70 Start Stop Expansion Listing mlist mnolist Two directives enable you to control the listing of macro and repeatable block expansions in the listing file d the listing file m By default the assembler behaves as if the mlist directive had been specified This example defines a macro named STR_3 The second time the macro is called the macro expansion is not listed because a mnolist directive was assembled The third time the macro is called the macro expansion is listed The mlist directive allows macro and loop endloop block expansions in The mnolist directive suppresses macro and loop endloop block expansions in the listing file because a mlist directive was assembled i 2 3 4 5 000000 1 000000 003A 000001 0070 000002 0031 000003 003A 000004 003A 000005 0070 000006 0032 000007 003A 000008 003A 000009 007
321. minates assembly It should be the last source statement of a program This directive has the same effect as an end of file The far mode directive tells the assembler that calls are far calls The mmregs directive defines symbolic names for the memory mapped register Using mmregs is the same as executing a set for all memory mapped registers See Table 4 2 on page 4 71 for a list of memory mapped registers The newblock directive resets local labels Local labels are symbols of the form n or name They are defined when they appear in the label field Local labels are temporary labels that can be used as operands for jump instructions The newblock directive limits the scope of local labels by resetting them after they are used For more information about local labels see subsection 3 8 6 Local Labels on page 3 22 The sblock directive designates sections for blocking Blocking is an address alignment mechanism similar to page alignment but weaker A blocked section is guaranteed not to cross a page boundary 128 words ifitis smaller than a page or to start on a page boundary if itis larger than a page Note that this directive allows specification of blocking for initial ized sections only not uninitialized sections declared with usect or the bss section The section names may or may not be enclosed in quotes The noremark directive begins a block of code in which the assembler will suppress the specified assembler remar
322. msg ERROR Missing Parameter mexit elseif symlen y 0 emsg ERROR Missing Parameter mexit else LD y A LD x B ADD A B endif endm testparam 1 2 if symlen x 0 emsg ERROR Missing Parameter mexit elseif Ssymlen y 0 emsg ERROR Missing Parameter mexit else LD 2 A LD 1 B ADD A B endif testparam if symlen x 0 emsg ERROR Missing Parameter ERROR Missing Parameter mexit 5 20 Formatting the Output Listing 5 8 Formatting the Output Listing Macros substitution symbols and conditional assembly directives may hide information You may need to see this hidden information so the macro language supports an expanded listing capability By default the assembler shows macro expansions and false conditional blocks in the output list file You may wantto turn this listing off or on within your listing file Four sets of directives enable you to control the listing of this information m m m m Macro and Loop Expansion Listing mlist expands macros and loop endloop blocks The mlist directive prints all code encountered in those blocks mnolist suppresses the listing of macro expansions and loop endloop blocks For macro and loop expansion listing mlist is the default False Conditional Block Listing fclist causes the assembler to include in the listing file all conditional blocks that do no
323. n the macro calls itself When you create recursive or nested macros you should pay close attention to the arguments that you pass to macro parameters because the assembler uses dynamic scoping for parameters This means that the called macro uses the environment of the macro from which it was called Example 5 15 shows nested macros Note that the y in the in block macro hides the y in the out block macro The x and z from the out block macro however are accessible to the in block macro Example 5 15 Using Nested Macros 5 22 in block macro y a Visible parameters are y a and s x z from the calling macro endm out block macro x y z visible parameters are x y z in block x y macro call with x and y as arguments endm out block macro call Using Recursive and Nested Macros Example 5 16 shows recursive macros The fact macro produces assembly code necessary to calculate the factorial of n where n is an immediate value The result is placed in data memory address loc The fact macro accomplishes this by calling fact1 which calls itself recursively Example 5 16 Using Recursive Macros a Mnemonic example fact macro N loc n is an integer constant loc memory address n zif N lt 2 0 1 1 ST 1 loc else ST N loc n gt 2 so store n at loc decrement n and do the eval N 1 N factorial of n 1 factl call fact with current environment endif
324. n Allocation Portion of Map File Resulting From the Command File Hex Command File for Converting a COFF File i Map File Resulting From the Command File in Example C 10 Hex Conversion Utility Output File Resulting From the Command File MOSO ee e a a r a E EE E E S E EE E C Code fora G54XLP 5 Linker Command File for a CBAxLP es Section Allocation Portion of Map File Resulting From the Command File in Example GG Hex Command File for Converting a COFF File i Map File Resulting From the Command File in Example C 16 Hex Conversion Utility Output File Resulting From the Command File in C 16 i C 23 Contents Xix Chapter 1 Introduction The TMS320C54x DSPs are supported by the following assembly language tools Assembler Archiver Linker Absolute lister Cross reference utility Hex conversion utility Mnemonic to algebraic translator utility D O UD D D UD LU This chapter shows how these tools fit into the general software tools develop ment flow and gives a brief description of each tool For convenience it also summarizes the C compiler and debugging tools For detailed information on the compiler and debugger and for complete descriptions of the TMS320C54x devices refer to the books listed in Related Documentation From Texas Instruments on page vi The assembly language tools create and use object files in common object file format COFF to facilitate mo
325. n The attributes are not some combination of R W and X Linker Error Messages E 7 Linker Error Messages E 8 illegal operator in expression Description Review legal expression operators illegal option within SECTIONS Description The 4 lowercase L option is the only option allowed within a SECTIONS directive illegal relocation type found in section s of file Description The binary file is corrupt internal error Description This linker has an internal error invalid archive size for file Description The archive file is corrupt invalid path specified with i flag Description The operand of the i option flag is not a valid file or path name invalid value for f flag Description The value for f option flag is not a 2 byte constant invalid value for heap flag Description The value for heap option flag is not a 2 byte constant invalid value for stack flag Description The value for stack option flag is not a 2 byte constant invalid value for v flag Description The value for v option flag is not a constant l O error on output file Description The disk may be full or protected Action Check disk volume and protection Linker Error Messages length redefined for memory area Description A memory area in a MEMORY directive has more than one length library member has no relocation information Description The librar
326. n address or a global symbol b Options for C54x LP devices only Option bootorg WARM or warm bootorg COMM spc value spce value arr value bkr value tcsr value trta value swwsr value bscr value Description Specify the source of the boot loader table as the table cur rently in memory Specify the source of the boot loader table as the commu nications port Set the serial port control register value Set the serial port control extension register value Set the ABU receive address register value Set the ABU transmit buffer size register value Set the TDM serial port channel select register value Set the TDM serial port receive transmit address register value Set the software wait state register value for PARALLEL WARM boot mode Set the bank switch control register value for PARALLEL WARM boot mode Hex Conversion Utility Description 10 29 Building a Table for an On Chip Boot Loader 10 9 3 1 Building the Boot Table 10 30 To build the boot table follow these steps Step 1 Link the file Each block of the boot table data corresponds to an initialized section in the COFF file Uninitialized sections are not con verted by the hex conversion utility see Section 10 6 The SECTIONS Directive on page 10 22 When you select a section for placement in a boot loader table the hex conversion utility places the section s oad adaress in the des tination address f
327. n entries These two partially linked files can then be linked together safely with the following command lnk500 bpart out dpart out o system out 7 4 8 Define Heap Size heap constant Option The C C compiler uses an uninitialized section called sysmem for the C runtime memory pool used by malloc You can set the size of this memory pool at link time by using the heap option Specify the size in words as a constant immediately after the option 1nk500 heap 0x0400 defines a heap size The linker creates the sysmem section only if there is a sysmem section in one of the input files Linker Options The linker also creates a global symbol SYSMEM SIZE and assigns it a value equal to the size of the heap The default size is 1K words For more information about linking C code see Section 7 17 Linking C Code on page 7 72 7 4 9 Alter the Library Search Algorithm l Option i Option and C54X C DIR C DIR Environment Variables Usually when you wantto specify a library as linker input you simply enter the library name as you would any other input filename the linker looks for the library in the current directory For example suppose the current directory contains the library object lib Assume thatthis library defines symbols that are referenced in the file file1 obj This is how you link the files lnk500 filel obj object lib If you want to use a library that is not in the current directory use the
328. n entry 2 global X 3 0000 FF80 B X 0001 0000 In this example the virtual address of the relocatable field is 0001 The symbol table index is the index of the referenced symbol In the preceding example this field would contain the index of X in the symbol table The amount of the relocation is the difference between the symbol s current address in the section and its assembly time address The relocatable field must be relocated by the same amount as the referenced symbol In the example X has a value of 0 before relocation Suppose X is relocated to address 2000h This is the relocation amount 2000h 0 2000h so the relocation field at address 1 is patched by adding 2000h to it You can determine a symbol s relocated address if you know which section it is defined in For example if X is defined in data and data is relocated by 2000h X is relocated by 2000h Structuring Relocation Information If the symbol table index in a relocation entry is 1 OFFFFh this is called an internal relocation In this case the relocation amount is simply the amount by which the current section is being relocated The relocation type specifies the size ofthe field to be patched and describes how to calculate the patched value The type field depends on the addressing mode that was used to generate the relocatable reference In the preceding example the actual address of the referenced symbol X will be placed in a 16 bitfield in the
329. n nested within the group Consider the following example SECTIONS GROUP load ROM run ROM textl UNION text2 text3 The load allocator given for the group does not uniquely specify the load allocation for the elements within the union text2 and text3 In this case the linker will issue a diagnostic message to request that these load alloca tions be specified explicitly Overlay Pages 7 11 Overlay Pages Some target systems use a memory configuration in which all or part of the memory space is overlaid by shadow memory This allows the system to map different banks of physical memory into and out of a single address range in response to hardware selection signals In other words multiple banks of physical memory overlay each other at one address range You may want the linker to load various output sections into each of these banks or into banks that are not mapped at load time The linker supports this feature by providing overlay pages Each page represents an address range that must be configured separately with the MEMORY directive You can then use the SECTIONS directive to specify the sections to be mapped into various pages 7 11 1 Using the MEMORY Directive to Define Overlay Pages To the linker each overlay page represents a completely separate memory comprising the full 24 bit range of addressable locations This allows you to link two or more sections at the same or overlapping addre
330. n symbol listing default Set tab size Print a title in the listing page heading Set the page width of the source listing 4 2 NI E FE PRY v i i IRI l H G THEI EIT Al lol S 9 IN LZ l gt St xl Ja N o lol ISl Lo co Go Lo Directives Summary Table 4 1 Assembler Directives Summary Continued e Directives that reference other files Mnemonic and Syntax Description Page copy filename Include source statements from another file 4 36 def symbol symbol Identify one or more symbols that are defined in the 4 51 current module and may be used in other modules global symbol symbol Identify one or more global external symbols 4 51 include filename Include source statements from another file 4 36 ref symbol symbol Identify one or more symbols that are used in the cur 4 51 rent module but may be defined in another module f Directives that define macros Mnemonic and Syntax Description Page macro Identify the source statement as the first line of a 4 67 macro definition You must place macro in the opcode field mlib filename Define macro library 4 68 mexit Go to endm This directive is useful when error test ing confirms that macro expansion will fail endm End macro code block 4 44 Var Define a local macro substitution symbol 4 98 g Directives that con
331. name etc binding Aprocess in which you specify a distinct address for an output sec tion or a symbol block A set of declarations and statements that are grouped together with braces bss One of the default COFF sections You can use the bss directive to reserve a specified amount of space in the memory map that can later be used for storing data The bss section is uninitialized C compiler A program that translates C source statements into assembly language source statements COFF Common object file format A binary object file format that promotes modular programming by supporting the concept of sections command file A file that contains options filenames directives or com ments for the linker or hex conversion utility comment A source statement or portion of a source statement that is used to document or improve readability of a source file Comments are not compiled assembled or linked they have no effect on the object file common object file format See COFF conditional processing A method of processing one block of source code or an alternate block of source code according to the evaluation of a specified expression configured memory Memory that the linker has specified for allocation constant A numeric value that can be used as an operand cross reference listing An output file created by the assembler that lists the symbols that were defined what line they were defined on which lines
332. name must follow host operating sys tem conventions it may be enclosed in double quotes You can specify a full pathname for example c dsp macs lib If you do not specify a full pathname the assembler searches for the file in 1 The directory that contains the current source file 2 Any directories named with the i assembler option 3 Any directories specified by the environment variable A DIR For more information about the i option and the environment variable see Section 3 4 Naming Alternate Directories for Assembler Input on page 3 8 When the assembler encounters a mlib directive it opens the library and creates a table of the library s contents The assembler enters the names of the individual library members into the opcode table as library entries This re defines any existing opcodes or macros that have the same name If one of these macros is called the assembler extracts the entry from the library and loads it into the macro table The assembler expands the library entry in the same way it expands other macros but it does not place the source code into the listing Only macros that are actually called from the library are extracted and they are extracted only once Define Macro Library mlib Example This example creates a macro library that defines two macros incr and decr The file incr asm contains the definition of incr and decr asm contains the defi nition of decr incr asm decr asm Macro for incre
333. ne a symbol illegally Action Correct the source per the error message text Assembler Error Messages Cannot redefine local substitution symbol Substitution stack overflow Substitution symbol not found Description These are errors about general substitution symbols An attempt was made to redefine a symbol or to define a symbol illegally Action Correctthe source perthe error message text Make sure that the operand of a substitution symbol is defined either as a macro parameter or with a asg or eval directive Symbol table entry is not balanced Description A symbolic debugging directive does not have a complement ing directive i e a block without an endblock Action Check the source for mismatched conditional assembly directives Macro argument string is too long Missing macro name Too many variables declared in macro Description These are errors about general macros A macro definition was probably corrupted Action Correct the source per the error message text Macro definition not terminated with endm Matching endm missing Assembler Error Messages D 11 Assembler Error Messages Matching macro missing mexit directive outside macro definition No active macro definition Description These are errors about macro definition directives A macro directive does not have a complementing directive that is a macro without a endm Action Correct the source per the error message text Bad archive ent
334. ng The bss section is usually present in a COFF file There is no requirement for it to be present output file has no data section Description This is a warning The data section is usually present in a COFF file There is no requirement for it to be present output file has no text section Description This is a warning The text section is usually present in a COFF file There is no requirement for it to be present output file not executable Description The output file created may have unresolved symbols or other problems stemming from other errors This condition is not fa tal overwriting aux entry filename of symbol n Description The input file may be corrupt Action If the input file is corrupt try reassembling it Linker Error Messages PC relative displacement overflow at address in file Description The relocation of a PC relative jump resulted in a jump dis placement too large to encode in the instruction r incompatible with s s ignored Description Both the r option and the s option were used Since the s option strips the relocation information and r requests a relo catable object file these options are in conflict with each oth er relocation entries out of order in section of file Description The input file may be corrupt Action If the input file is corrupt try reassembling it relocation symbol not found index section file De
335. ng the references are resolved as shown lnk500 fl obj liba lib f2 0bj libc lib J Member 1 of liba lib satisfies both references to clrscr because the library is searched and clrscr is defined before f2 obj references it D Member 0 of libc lib satisfies the reference to origin QJ Member 3 of liba lib satisfies the reference to fillclr Linker Description 7 25 Object Libraries 7 26 If however you enter the following all the references to clrscr are satisfied by member 1 of libc lib 1nk500 fl obj f2 0bj libc lib liba lib If none of the linked files reference symbols defined in a library you can use the u option to force the linker to include a library member The next example creates an undefined symbol rout1 in the linker s global symbol table 1nk500 u routl libc lib If any member of libc lib define rout1 the linker includes those members It is not possible to control the allocation of individual library members members are allocated according to the SECTIONS directive default allocation algorithm Subsection 7 4 9 Alter the Library Search Algorithm i dir Option C DIR on page 7 13 describes methods for specifying directories that contain object libraries The MEMORY Directive 7 7 The MEMORY Directive The linker determines where output sections should be allocated in memory it must have a model of target memory to accomplish this task The MEMORY directive allows you to specify a model of tar
336. ng word even boundary 128 aligns SPC to page boundary The align directive with no operands defaults to a page boundary The even directive aligns the SPC so that it points to the next word boundary It is equivalent to specifying the align directive with an operand of 1 Using even with an operand of 2 aligns the SPC to the next long word boundary Any unused bits in the current word are filled with Os Figure 4 4 demonstrates the align directive Assume that the following code has been assembled 1 000000 4000 field 2 o3 2 000000 4160 field 11 8 3 align 2 4 000002 0045 string Errorcnt 000003 0072 000004 0072 000005 006f 000006 0072 000007 0063 000008 006e 000009 0074 5 align 6 000080 0004 byte 4 Assembler Directives 4 15 Directives That Align the Section Program Counter Figure 4 4 The align Directive a Result of align 2 00h b New SPC 02h after er 2 words T 1 a Current 02h E ped SPC a align 00h directive b Result of align without an argument 00h ee 128 a Current words b New SPC SPC 80h after assembling 80h a align directive 4 16 Directives That Format the Output Listing 4 6 Directives That Format the Output Listing The following directives format the listing file Youcanusethe drnolist directive to suppress the printing of the following directives in the listing asg eval length mnolist var break fclist mlist SSlist W
337. nker can assign one of four possible values to the entry point These values are listed below in the order in which the linker tries to use them If you use one of the first three values it must be an external symbol in the symbol table J The value specified by the e option The syntax is e global symbol Where global symbol defines the entry point and must appear as an external symbol in one of the input files The value of symbol c int0O if present c _int00 must be the entry point if you are linking code produced by the C C compiler The value of symbol main if present D Zero default value This example links file1 obj and file2 obj The symbol begin is the entry point begin must be defined as external in file1 or file2 1nk500 e begin filel obj file2 obj 7 4 5 Set Default Fill Value f cc Option The f option fills the holes formed within output sections or initializes uninitial ized sections when they are combined with initialized sections This allows you to initialize memory areas during link time without reassembling a source file The argument ccis a 16 bit constant up to four hexadecimal digits If you do not use f the linker uses 0 as the default fill value This example fills holes with the hexadecimal value ABCD 1nk500 f OABCDh filel obj file2 0bj Linker Description 7 11 Linker Options 7 4 6 Make a Symbol Global g global symbol Option The h option makes all global
338. nker option bes directive big endian ordering binary integer constants binding defined named memor sections bkr hex conversion utility option block auxiliary table entry defined described reference block symbolic debugging directive blocking boot hex conversion utility option boot loader See on chip boot loader boot table See on chip boot loader boot table boot obj bootorg hex conversion utility option 10 29 10 32 bootpage hex conversion utility option 10 29 specifying type Index 3 Index 4 66 break directive listing control 4 17 4 41 use in macros bscr hex conversion utility option bss directive compatibility with C1x C2x C2xx C5x in sections linker definition 7 65 bss section 4 9 defined holes initializing built in functions byte hex conversion utility option byte directive 4 12 4 39 limiting listing with option directive 4 17 4 76 C memory pool 17 12 7 73 system stack C assembler option linker option 7 10 C code linking 7 72 to C compiler block definitions B 3 COFF technical details defined enumeration definitions file identification function definitions line number entries line number information linking 7 10 7 72 to Lu member oe S special symbols Pe storage classes structure definitions B 9 symbol table entries union definitions B 9 C DIR environment variable 7 13 to 7 16 c int00 c mode
339. nother GROUP An option of the SECTIONS directive that forces specified output sections to be allocated contiguously as a group Glossary F 3 Glossary hex conversion utility A program that accepts COFF files and converts them into one of several standard ASCII hexadecimal formats suitable for loading into an EPROM programmer high level language debugging The ability of a compiler to retain sym bolic and high level language information such as type and function definitions so that a debugging tool can use this information hole An area between the input sections that compose an output section that contains no actual code or data incremental linking Linking files that will be linked in several passes Often this means a very large file that will have sections linked and then will have the sections linked together initialized section A COFF section that contains executable code or initial ized data An initialized section can be built up with the data text or Sect directive input section A section from an object file that will be linked into an executable module label A symbol that begins in column 1 of a source statement and corre sponds to the address of that statement line number entry An entry in a COFF output module that maps lines of assembly code back to the original C source file that created them linker A software tool that combines object files to form an object module that can be allocated
340. ns SECTIONS 5821 gl obj g2 0bj gn obj Step 3 Link tempout1 out and tempout2 out lnk500 m final map o final out tempoutl out tempout2 out Linker Description 7 71 Linking C C Code 7 17 Linking C C Code The TMS320C54x C C compiler produces assembly language source code that can be assembled and linked For example a C C program consisting of modules prog1 prog2 etc can be assembled and then linked to produce an executable file called prog out 1nk500 c o prog out progl obj prog2 obj rts lib The c option tells the linker to use special conventions that are defined by the C C environment The runtime library contains C C runtime support functions For more information about C C including the runtime environment and runtime support functions see the TMS320C54x Optimizing C C Compiler User s Guide 7 17 1 Runtime Initialization All C C programs must be linked with an object module called boot obj When a program begins running it executes boot obj first boot obj contains code and data for initializing the runtime environment The module performs the following tasks Sets up the system stack Processes the runtime initialization table and autoinitializes global variables in the ROM model Disables interrupts and calls main The runtime support object library rts lib contains boot obj You can D Use the archiver to extract boot obj from the library
341. ns For example assume you want to load a COFF section sec1 at address 0x0100 of an 8 bit EPROM If you specify the load address in the linker com Hex Conversion Utility Description 10 37 Controlling the ROM Device Adaress mand file at location 0x0100 the hex conversion utility will multiply the address by 2 data width divided by memory width 16 8 2 giving the output file a starting address of 0x0200 Unless you control the starting address of the EPROM with your EPROM programmer you could create holes within the EPROM The programmer will burn the data starting at location 0x0200 instead of 0x0100 To solve this you can Usethe paddr parameter of the SECTIONS directive This forces a sec tion to start at the specified value Figure 10 9 shows a command file that can be used to avoid the hole at the beginning of sec1 Figure 10 9 Hex Command File for Avoiding a Hole at the Beginning of a Section 10 38 i a out map a map ROMS ROM org 0x0100 length 0x200 romwidth 8 memwidth 8 SECTIONS secl paddr 0x100 Note If your file contains multiple sections and if one section uses a paddr parameter then all sections must use the paddr parameter Use the bootorg option or use the ROMS origin parameter for boot loading only As described on page 10 36 when you are boot loading the EPROM address of the entire boot loader table can be controlled by the bootorg o
342. ns the result of expr rounded toward zero Assembler Description 3 31 Loading Values into Extended Program Memory 3 11 Loading Values into Extended Program Memory The assembler accepts a pseudo op L function etc that resides or may reside DX for loading the value of a label in extended program memory LDX is used to load the upper 8 bits of a 24 bit address For example if a function F1 is in extended program memory which is 24 bits instead of 16 the value or address of F1 may be loaded as follows LDX F1 16 A loads the upper 8 bits of the 24 bit address of OR F1 A A adds in the address of BACC A all 24 bits into accumu F1 lower 16 bits of the F1 of F1 have been loaded lator A Note that it is necessary to use both LDX and OR to load the entire 24 bit address Source Listings 3 12 Source Listings A source listing shows source statements and the object code they produce To obtain a listing file invoke the assembler with the lowercase L option Two banner lines a blank line and a title line are at the top of each source list ing page Any title supplied by a title directive is printed on the title line a page number is printed to the right of the title If you don t use the title directive the name of the source file is printed The assembler inserts a blank line below the title line Each line in the source file may produce a line in the listing file that shows a s
343. nspecified bits These are examples of valid binary constants 00000000B Constant equal to 049 or 016 0100000b Constant equal to 3249 or 2016 01b Constant equal to 149 or 146 11111000B Constant equal to 24849 or OF816 3 6 2 Octal Integers An octal integer constant is a string of up to 6 octal digits 0 through 7 prefixed with a 0 zero or suffixed with Q or q These are examples of valid octal constants 10Q Constant equal to 819 or 816 100000Q Constant equal to 32 76849 or 8 00046 226q Constant equal to 15049 or 9646 Or you can use C notation for octal constants 010 Constant equal to 849 or 816 0100000 Constant equal to 32 76849 or 8 00046 0226 Constant equal to 15049 or 9646 Assembler Description 3 15 Constants 3 6 3 Decimal Integers 3 6 4 Hexadecimal A decimal integer constant is a string of decimal digits ranging from 32 768 to 65 535 These are examples of valid decimal constants 1000 Constant equal to 100049 or 3E816 32768 Constant equal to 32 76849 or 8 00046 25 Constant equal to 2549 or 1946 Integers A hexadecimal integer constant is a string of up to four hexadecimal digits followed by the suffix H or h Hexadecimal digits include the decimal values 0 9 and the letters A F and a f A hexadecimal constant must begin with a decimal value 0 9 If fewer than four hexadecimal digits are specified the assembler right justifies the bits These are examples of valid hexadecimal constants 78h
344. nstants and expressions and assembler output 3 4 Assembler Overview os 3 2 Assembler Development Flow 39 3 Invoking the Assembler pp vii Contents 3 4 Naming Alternate Files and Directories for Assembler Input i 3 4 1 Using the i Assembler Option pp 3 4 2 Using Environment Variables C54X A DIR and A DIR 3 5 Source Statement Format cece cent eee eee 3 5 4 Source Statement Syntax i 3 5 2 Label Field veg odd sese Ere re Rr RAW A de DA ae a ERE DINER 3 5 8 Mnemonic Instruction Fields 00 cece danes eee 3 5 4 Algebraic Instruction Field 0 0 cece eee 3 5 5 Comment Field a a a ee 3 6 Constants so oa er senig we da ee et a dor a i US 3 6 1 Binary Integers sn ses a km i ds 3 6 2 Octal Integers nm in i ue gue li es ra ehh e med d 3 6 3 Decimal Integers se 3 6 4 Hexadecimal Integers i 3 6 5 Character Constants ori rieisiu ria iraa e na a a EA 3 6 6 Floating Point Constants 0 0 cece eee eens 3 7 Character Strings a nett eens 3 8 OVMDOIS sc 2s i gn edad gel Rav abdbe ds Shaded de debe lt 3 8 2 Symbolic Constants sesi srei 0000 a dante eet eee seen dee aed de 3 8 3 Defining Symbolic Constants d Option pp 3 8 4 Predefined Symbolic Constants 1 3 85 Substitution Symbols sss seses errai asiaani tenes 9 0 6 Local Labeli oes voted e ERA ER ISEORELS AN EIS 9 9 Expressions sie Lace dae da EE Del 4E E pup ROS ed hahha drehen dd 3
345. nstants b t8itofs 17 cross reference listings defined described error messages D 1 to D 18 expressions extended addressing suppor 3 321 handling COFF sections P oto 2 12 handling pipeline conflicts in the development flow invoking LDX pseudorop macros 5 1 to 5 26 options E id usage information 5 8 3 20 5 33 output Tee directive listing K 17 to 4 18 4 41 to 4 100 iiia s EE overview relocation at runtime 2 19 described to during linking 8 remarks suppressing sections directives 2 5 to 2 12 source listings 3 33 to 3 36 suppressing remarks 3 6 symbols Index 2 assembler directives 4 1 to 4 25 absolute lister Setsect setsym aligning the section program counter compatibility with C1x C2x C2xx C5x default directive defining assembly time symbols 4 21lto 4 22 asg endstruct endunion enabling conditional assembly example 2 10 to 0 12 formatting ie output listing 4 17 to Ae nolist option page Sslist assembler directives formatting the output listing continued ssnolist miscellaneous algebraic Index assembler directives continued referencing other files assembly time constants 4 81 defined assignment statement defined expressions 7 63 to attr MEMORY specification attributes autoinitialization defined described 7 73 to 7 74 auxiliary entr defined described A 23 to A 28 b li
346. nt from an align directive or previous link The binding address violates this requirement blocking for must be a power of 2 Description Section blocking is not a power of 2 Action Make sure that in hexadecimal all powers of 2 consist of the integers 1 2 4 or 8 followed by a series of zero or more Os Linker Error Messages blocking for redefined Description More than one blocking value is supplied for a section c requires fill value of 0 in cinit overridden Description The cinit tables must be terminated with O therefore the fill value of the cinit section must be 0 cannot complete output file write error Description This usually means that the file system is out of space cannot create output file Description This usually indicates an illegal filename Action Check spelling pathname environment variables etc The filename must conform to operating system conventions cannot resize section has initialized definition in Description An initialized input section named stack or heap exists pre venting the linker from resizing the section cannot specify a page for a section within a GROUP Description A section was specified to a specific page within a group The entire group is treated as one unit so the group may be speci fied to a page of memory but the sections making up the group cannot be handled individually cannot specify both binding and memory
347. nt types for example absolute value compared to absolute value but not absolute value compared to relocatable value Assembler Description 3 27 Expressions 3 9 5 Relocatable Symbols and Legal Expressions Table 3 2 summarizes valid operations on absolute relocatable and external symbols An expression cannot contain multiplication or division by a relocatable or external symbol An expression cannot contain unresolved symbols that are relocatable to other sections Symbols or registers that have been defined as global with the global directive can also be used in expressions in Table 3 2 these symbols and registers are referred to as external Relocatable registers can be used in expressions the addresses of these registers are relocatable with respect to the register section they were defined in unless they have been declared as external Table 3 2 Expressions With Absolute and Relocatable Symbols 3 28 If Ais and If Bis then A Bis and A Bis absolute absolute absolute absolute absolute external external illegal absolute relocatable relocatable illegal relocatable absolute relocatable relocatable relocatable relocatable illegal absolute relocatable external illegal illegal external absolute external external external relocatable illegal illegal external external illegal illegal T A and B must be in the same section otherwise this is illegal Following are examples of expressions that use relocat
348. nto the text output section The linker concatenates the text input sections in the order that it encounters them in the input files The linker performs similar operations with the data and bss sections You can use this type of specification for any output section You can explicitly specify the input sections that form an output section Each input section is identified by its filename and section name SECTIONS text Build text output section if fl obj text Link text section from fl obj f 2 0bj secl Link secl section from f2 0bj 3 053 Link ALL sections from f3 0bj f4 obj text sec2 Link text and sec2 from f4 0obj It is not necessary for input sections to have the same name as each other or as the output section they become part of If a file is listed with no sections all of its sections are included in the output section If any additional input sec tions have the same name as an output section but are not explicitly specified by the SECTIONS directive they are automatically linked in at the end of the output section For example if the linker found more text sections in the preceding example and these text sections were not specified anywhere in the SECTIONS directive the linker would concatenate these extra sections after f4 obj sec2 The specifications in Example 7 5 are actually a shorthand method for the following SECTIONS text text data
349. nts 4 4 Directives That Initialize Constants This section describes several directives that assemble values for the current section The bes and space directives reserve a specified number of bits in the current section The assembler fills these reserved bits with Os You can reserve words by multiplying the desired number of words by 16 When you use a label with space it points to the first word that contains reserved bits When you use a label with bes it points to the ast word that contains reserved bits Figure 4 1 shows the space and bes directives Assume the following code has been assembled for this example 1 BUCO PO Oo 1 OY O1 9 10 11 Space and bes directives 000000 0100 word 100h 200h 000001 0200 000002 Res 1 Space 17 000004 000f word 15 000006 Res_2 bes 20 000007 00ba byte OBAh reserve 3 words 000008 Res_3 Space 3 16 00000b 000a word 10 Res 1 points to the first word in the space reserved by space Res 2 points to the last word in the space reserved by bes Figure 4 1 The space and bes Directives 17 bits reserved 20 bits reserved Res 1 02h Res 2 06h Assembler Directives 4 11 Directives That Initialize Constants The byte ubyte char and uchar directives place one or more 8 bit values into consecutive words of the current section These directives are similar to word and uword except th
350. nts is as follows Mnemonic syntax abel mnemonic operand list comment Algebraic syntax label instruction comment Follow these guidelines DD All statements must begin with a label a blank an asterisk or a semico lon D A statement containing an assembler directive must be specified entirely on one line Labels are optional if used they must begin in column 1 One or more blanks must separate each field Tab characters are equivalent to blanks D Comments are optional Comments that begin in column 1 can begin with an asterisk or a semicolon or but comments that begin in any other column must begin with a semicolon Assembler Description 3 11 Source Statement Format 3 5 2 Label Field Labels are optional for all assembly language instructions and for most but not all assembler directives When used a label must begin in column 1 of a source statement A label can contain up to 32 alphanumeric characters A Z a z 0 9 _ and Labels are case sensitive and the first character cannot be a number A label can be followed by a colon the colon is not treated as part of the label name If you don t use a label the first character position must contain a blank a semicolon or an asterisk When you use a label its value is the current value of the section program counter the label points to the statement it s associated with If for example you use the wor
351. nts must be preceded by a semicolon or an asterisk if the comment is the only statement on the line To improve readability labels and comments are not shown as part of the directive syntax For some directives however a label is required and will be shown in the syntax Table 4 1 Assembler Directives Summary a Directives that define sections Mnemonic and Syntax Description Page bss symbol size in words blocking Reserve size words in the bss uninitialized data 4 30 alignment section clink section name Enables conditional linking for the current or specified 4 34 section data Assemble into the data initialized data section sect section name Assemble into a named initialized section 4 80 text Assemble into the text executable code section 4 90 symbol usect section name size in words Reserve size words in a named uninitialized section 4 95 blocking alignment Directives Summary Table 4 1 Assembler Directives Summary Continued b Directives that initialize constants data and memory Mnemonic and Syntax bes size in bits byte value values char value values double value values ldouble value value field value size in bits float value value half value values Short value valuen int value value long value valuen pstring string string sp
352. o Tota Len TUB GIU lee Ls TOD LPN EOS 00000001FF LI LJ L Checksum Byte Record count type End of file record Hex Conversion Utility Description 10 41 Description of the Object Formats 10 11 3 Motorola Exorciser Object Format m1 m2 m3 Options The Motorola S1 S2 and S3 formats support 16 bit 24 bit and 32 bit addresses respectively The formats consist of a start of file header record data records and an end of file termination record Each record is made up of five fields record type byte count address data and checksum The record types are Record Type Description S0 Header record 1 Code data record for 16 bit addresses S1 format S2 Code data record for 24 bit addresses S2 format S3 Code data record for 32 bit addresses S3 format S7 Termination record for 32 bit addresses S3 format S8 Termination record for 24 bit addresses S2 format S9 Termination record for 16 bit addresses S1 format The byte count is the character pair count in the record excluding the type and byte count itself The checksum is the least significant byte of the 1s complement of the sum ofthe values represented by the pairs of characters making up the byte count address and the code data fields Figure 10 12 illustrates the Motorola S object format Figure 10 12 Motorola S Format
353. object code This is a 16 bit direct relocation so the relocation type is R RELWORD Table A 8 lists the relocation types Table A 8 Relocation Types Bytes 8 and 9 Mnemonic Flag Relocation Type R ABS 0000h No relocation R REL24 0005h 24 bit direct reference to symbol s address R RELBYTE 0017h 8 bit direct reference to symbol s address R REL13 002Ah 13 bit direct reference R RELWORD 0020h 16 bit direct reference to symbol s address R RELLONG 0021h 32 bit direct reference to symbol s address R PARTLS7 0028h 7 LSBs of an address R_PARTMS9 0029h 9 MSBs of an address Common Object File Format A 11 Line Number Table Structure A 6 Line Number Table Structure The object file contains a table of line number entries that are useful for symbolic debugging When the C C compiler produces several lines of assembly language code it creates a line number entry that maps these lines back to the original line of C C source code that generated them Each sin gle line number entry contains 6 bytes of information Table A 9 shows the for mat of a line number entry Table A 9 Line Number Entry Format Byte Number Type Description 0 3 Long integer This entry may have one of two values 1 If itis the first entry in a block of line number entries it points to a symbol entry in the symbol table 2 If itis not the first entry in a block it is the physical ad dress of the line indicated by bytes 4 5 4 5 Unsigned This entry may
354. ocated relocated loaded STYP DSECT 0001h Dummy section relocated not allocated not loaded STYP NOLOAD 0002h Noload section allocated relocated not loaded STYP GROUP 0004h Grouped section formed from several input sections STYP PAD 0008h Padding section loaded not allocated not relocated STYP COPY 0010h Copy section relocated loaded but not allocated relo cation and line number entries are processed normally STYP TEXT 0020h Section that contains executable code STYP DATA 0040h Section that contains initialized data STYP BSS 0080h Section that contains uninitialized data STYP_CLINK 4000h Section that is conditionally linked Note The term oaded means that the raw data for this section appears in the object file The flags are in 36 and 37 COFF1 40 to 43 COFF2 Section Header Structure Figure A 3 illustrates how the pointers in a section header would point to the elements in an object file that are associated with the text section Figure A 3 Section Header Pointers for the text Section text 0 7 8 11 12 15 16 19 20 23 24 27 28 31 32 33 34 35 36 37 38 39 text raw data text relocation information text line number entries As Figure A 2 on page A 3 shows uninitialized sections created with the bss and usect directives vary from this format Although uninitialized sections have section headers they have no raw data relocation information or line nu
355. odel allows variables to be initialized at load time instead of runtime raw data Executable code or initialized data in an output section relocation A process in which the linker adjusts all the references to a sym bol when the symbol s address changes ROM model An autoinitialization model used by the linker when linking C code The linker uses this model when you invoke the linker with the c option In the ROM model the linker loads the cinit section of data tables into memory and variables are initialized at runtime Glossary ROM width The width in bits of each output file or more specifically the width of a single data value in the file The ROM width determines how the utility partitions the data into output files After the target words are mapped to memory words the memory words are broken into one or more output files The number of output files is determined by the ROM width run address The address where a section runs section A relocatable block of code or data that will ultimately occupy con tiguous space in the TMS320C54x memory map section header A portion of a COFF object file that contains information about a section in the file Each section has its own header the header points to the section s starting address contains the section s size etc section program counter See SPC sign extend To fill the unused MSBs of a value with the value s sign bit simulator A software development syst
356. of size and type that may be temporarily stored in the same memory space The tag directive associates union characteristics with a label symbol A union can be defined and given a tag and later it can be declared as a member of a structure by using the tag directive A union may also be de clared without a tag in which case all of its members will be entered in the symbol table and each member must have a unique name A union may also be defined within a structure in which case any reference to such a union must be made via with the structure that encloses it For example data s2 tag struct Structure tag definition union union is first structure member sSEFUCE Structure is union member hl half hl h2 and wl h2 uhalf exist in the same memory endstruct wl word word is another union member endunion w2 word Second structure member s2 len endstruct XYZ tag s2 tag bss XYZ s2 len declare instance of structure ADD XYZ h2 A Miscellaneous Directives 4 10 Miscellaneous Directives These directives enable miscellaneous functions or features J The algebraic directive tells the assembler thatthe file contains algebraic assembly source code This must be the first line in the file if the mg assembler option is not used The c mode directive tells the assembler that calls and branches are within the normal 16 bit address range This is the default behavior of the assembler The end directive ter
357. of the text output section It marks the beginning of executable code etext is assigned the first address following the text output section It marks the end of executable code data is assigned the first address of the data output section It marks the beginning of initialized data tables edata is assigned the first address following the data output section It marks the end of initialized data tables bss is assigned the first address of the bss output section It marks the beginning of uninitialized data end is assigned the first address following the bss output section It marks the end of uninitialized data 7 14 5 Symbols Defined Only For C Support c or cr Option STACK SIZE is assigned the size of the stack section SYSMEM SIZE is assigned the size of the sysmem section Linker Description 7 65 Creating and Filling Holes 7 15 Creating and Filling Holes The linker provides you with the ability to create areas within output sections that have nothing linked into them These areas are called holes In special cases uninitialized sections can also be treated as holes The following text describes how the linker handles such holes and how you can fill holes and uninitialized sections with a value 7 15 1 Initialized and Uninitialized Sections An output section contains one of the following Lj Raw data for the entire section Li Noraw data A section that has raw data is referred to
358. of the tables Assigning Symbols at Link Time 7 14 2 Assigning the SPC to a Symbol A special symbol denoted by a dot represents the current value of the SPC during allocation The linker s symbol is analogous to the assembler s symbol The symbol can be used only in assignment statements within a SECTIONS directive because is meaningful only during allocation and SECTIONS controls the allocation process See Section 7 8 The SEC TIONS Directive on page 7 32 Note that the symbol cannot be used out side of the braces that define a single output section The symbol refers to the current run address not the current load address of the section For example suppose a program needs to know the address of the beginning of the data section By using the global directive you can create an external o undefined variable called Dstart in the program Then assign the value of to Dstart SECTIONS text 0 data Dstart bss This defines Dstart to be the first linked address of the data section Dstart is assigned before data is allocated The linker will relocate all references to Dstart A special type of assignment assigns a value to the symbol This adjusts the SPC within an output section and creates a hole between two input sec tions Any value assigned to to create a hole is relative to the beginning of on the section n
359. okes the cross reference utility identifies the cross reference lister options you want to use Options are not case sensitive and can appear any where on the command line following the command Pre cede each option with a hyphen The cross reference lister options are as follows lowercase L specifies the number of lines per page for the output file The format of the option is Inum where num is a decimal constant For example 4130 sets the number of lines per page in the output file to 30 The space between the option and the decimal constant is optional The default is 60 lines per page q quiet suppresses the banner and all progress information is a linked object file If you omit the input filename the utility prompts for a filename is the name of the cross reference listing file If you omit the output filename the default filename will be the input filename with an xrf extension Cross Reference Lister Description 9 3 Cross Reference Listing Example 9 3 Cross Reference Listing Example Symbol INIT Filename RTYP AsmVal LnkVal DefLn RefLn RefLn RefLn filel asm EDEF 000000 000080 3 1 file2 asm EREE 000000 000080 2 11 Symbol X Filename RTYP AsmVal LnkVal DefLn RefLn RefLn RefLn filel asm EREE 000000 000001 2 5 file2 asm EDEF 000001 000001 5 1 Symbol Y Filename RTYP AsmVal LnkVal DefLn
360. om the data section and you can reserve space for uninitialized variables that is separate from the bss section The following directives let you create named sections _j The usect directive creates sections that are used like the bss section These sections reserve space in RAM for variables DD The sect directive creates sections like the default text and data sections that can contain code or data The sect directive creates named sections with relocatable addresses The syntax for these directives is shown below symbol usect section name size in words blocking flag alignment flag sect section name The section name parameter is the name of the section You can create up to 32 767 separate named sections A section name can be up to 200 charac ters For the sect and usect directives a section name can refer to a subsec tion see subsection 2 3 4 Subsections for details Each time you invoke one of these directives with a new name you create a new named section Each time you invoke one of these directives with a name that was already used the assembler assembles code or data or reserves space into the section with that name You cannot use the same names with different directives That is you cannot create a section with the usect direc tive and then try to use the same section with sect How the Assembler Handles Sections 2 3 4 Subsections Subsections are smaller secti
361. ons within larger sections Like sections subsections can be manipulated by the linker Subsections give you tighter control of the memory map You can create subsections by using the sect or usect directive The syntax for a subsection name is section name subsection name A subsection is identified by the base section name followed by a colon then the name of the subsection A subsection can be allocated separately or grouped with other sections using the same base name For example to create a subsection called func within the text section enter the following Sect text func You can allocate func separately or with other text sections You can create two types of subsections J Initialized subsections are created using the sect directive See subsection 2 3 2 Initialized Sections on page 2 7 Uninitialized subsections are created using the usect directive See subsection 2 3 1 Uninitialized Sections on page 2 5 Subsections are allocated in the same manner as sections See Section 7 8 The SECTIONS Directive on page 7 32 for more information 2 3 5 Section Program Counters The assembler maintains a separate program counter for each section These program counters are known as section program counters or SPCs An SPC represents the current address within a section of code or data Initially the assembler sets each SPC to 0 As the assembler fills a section with code or data it increments th
362. onversion Utility Process Flow Raw data in COFF files is repre 2 sented in target width sized words For C54x this is 16 bits COFF input file The target width is fixed and cannot be changed The raw data in the COFF file is Phase truncated to the size specified by the default data width 16 bits The data width sized internal representation is divided into words Phase Il according to size specified by the memwidth option The memwidth sized words are broken up according to the size Pass ill specified by the romwidth option and are written to a file s according to the specified format i e Intel Tektronix etc Output file s Hex Conversion Utility Description 10 9 Understanding Memory Widths 10 4 1 Target Width 10 4 2 Data Width Target width is the unit size in bits of raw data fields in the COFF file This corresponds to the size of an opcode on the target processor The width is fixed for each target and cannot be changed The C54x targets have a width of 16 bits Data width is the logical width in bits of the data words stored in a particular section of a COFF file Usually the logical data width is the same as the target width The data width is fixed at 16 bits for the TMS320C54x and cannot be changed 10 4 3 Memory Width 10 10 Memory width is the physical width in bits ofthe memory system Usually the memory system is physically the same width as the target processor width
363. opied source lines in the listing file The second time this directive is encoun tered the assembler does not list the copied source lines because a nolist directive was assembled Note that the nolist the second copy and the list directives do not appear in the listing file Note also that the line counter is incremented even when source statements are not listed Source file Copy NOP copy2 asm Back in original file nolist copy2 asm CODY list Back in original file string Listing file 1 A 1 A 2 o Co N 000000 000001 000002 000005 000006 000007 000008 Done 0020 0042 F495 0044 006F 006E 0065 Start Stop Source Listing list nolist COPY copy2 asm In copy2 asm copy file Back Back word 32 1 A in original file NOP in original file string Done Assembler Directives 4 63 long ulong xlong Syntax Description Initialize Long Word ong value value ulong value valuen Xlong value valuen The long ulong and xlong directives place one or more 32 bit values into consecutive words in the current section The most significant word is stored first The long and ulong directives align the result on the long word boundary while the xlong directive does not A value can be Anexpression that the assembler evaluates and treats as an 32 bit signed or unsigned numbe
364. or Assembler Input 3 4 1 The copy include and mlib directives tell the assembler to use code from external files The copy and include directives tell the assembler to read source statements from another file and the mlib directive names a library that contains macro functions Chapter 4 Assembler Directives contains examples of the copy include and mlib directives The syntax for these directives is copy filename include filename mlib filename The filename names a copy include file that the assembler reads statements from or a macro library that contains macro definitions The filename may be a complete pathname a partial pathname or a filename with no path informa tion The assembler searches for the file in the following order 1 The directory that contains the current source file The current source file is the file being assembled when the copy include or mlib directive is encountered 2 Any directories named with the i assembler option 3 Any directories set with the environment variables C54X A DIR and A DIR 4 Any directories set with the environment variables C54X C DIR and C DIR You can augment the assembler s directory search algorithm by using the i assembler option or the C54X A DIR and A DIR environment variables Using the i Assembler Option The i assembler option names an alternate directory that contains copy include files or macro libraries The for
365. or blocking XC ck ck ck ck ck Ck ck ck KK KKK ck ck kk Ck ck kk kk kk ko Sk kk ck kc KK ko ko Specify blocking for the text EE and data sections WE Sblock text data C10 PN P Assembler Directives 4 79 Sect Assign Character Strings to Substitution Symbols Syntax Description Example 4 80 Sect section name The sect directive defines a named section that can be used like the default text and data sections The sect directive begins assembling source code into the named section The section name identifies a section that the assembler assembles code into The name can be up to 200 characters and must be enclosed in double quotes A section name can contain a subsection name in the form section name sub section name For COFF1 formatted files only the first 8 characters are signifi cant For more information about COFF sections see Chapter 2 Introduction to Common Object File Format This example defines a special purpose section named Vars and assembles code into it 1 2 Ex Begin assembling into text section ER 3
366. orce macro x loop 8 AUX x Set X eval x 1 x endloop endm force 0 The force macro would generate the following source code AUXO set 0 AUX1 set 1 AUX7 set 7 Macro Language 5 11 Macro Parameters Substitution Symbols 5 3 5 Accessing Individual Characters of Subscripted Substitution Symbols In a macro you can access the individual characters substrings of a substitu tion symbol with subscripted substitution symbols You must use the forced substitution operator for clarity You can access substrings in two ways symbol well defined expression This method of subscripting evaluates to a character string with one character Lj symbol well defined expression well defined expressions In this method expression represents the substring s starting position and expressions represents the substring s length You can specify exactly where to begin subscripting and the exact length of the resulting character string The index of substring characters begins with 1 not 0 Example 5 8 and Example 5 9 show built in substitution symbol functions used with subscripted substitution symbols In Example 5 8 subscripted substitution symbols redefine the add instruction so that it handles short immediates Example 5 8 Using Subscripted Substitution Symbols to Redefine an Instruction ADDX macro ABC Var TMP asg ABC 1 TMP f symcmp TMP 0 ADD ABC A else emsg Bad
367. ormats 10 11 1 ASCII Hex Object Format a Option The ASCII Hex object format supports 16 bit addresses The format consists of a byte stream with bytes separated by spaces Figure 10 10 illustrates the ASCII Hex format Figure 10 10 ASCII Hex Object Format Nonprintable Nonprintable Address end code start code d B SAXXXX ro XX XX XX XX XX XX XX XX XX XX C Data byte The file begins with an ASCII STX character ctrl B 02h and ends with an ASCII ETX character ctrl C 03h Address records are indicated with AXXXX in which XXXX is a 4 digit 16 bit hexadecimal address The address records are present only in the following situations DD When discontinuities occur When the byte stream does not begin at address 0 You can avoid all discontinuities and any address records by using the image and zero options The output created is a list of byte values 10 40 Description of the Object Formats 10 11 2 Intel MCS 86 Object Format i Option Figure 10 11 Start character Address i 2000000000000100020003000400050006000700080009000A000B000C000D000E000F0068 Most significant 16 bits The Intel object format supports 16 bit addresses and 32 bit extended addresses Intel format consists of a 9 character 4 field prefix which defines the start of record byte count load address and record type the data and a 2 character checksum suffix The 9 character prefix represents three r
368. ot to the address actually represented by Assignments to and holes are described in Section 7 15 Creating and Filling Holes on page 7 66 7 14 3 Assignment Expressions These rules apply to linker expressions DD Expressions can contain global symbols constants and the C language operators listed in Table 7 1 J All numbers are treated as long 32 bit integers J Constants are identified by the linker in the same way as by the assembler That is numbers are recognized as decimal unless they have a suffix H Linker Description 7 63 Assigning Symbols at Link Time or h for hexadecimal and Q or q for octal C language prefixes are also recognized 0 for octal and Ox for hex Hexadecimal constants must begin with a digit No binary constants are allowed D Symbols within an expression have only the value of the symbol s address No type checking is performed DD Linker expressions can be absolute or relocatable If an expression contains anyrelocatable symbols and zero or more constants or absolute symbols it is relocatable Otherwise the expression is absolute If a symbol is assigned the value of a relocatable expression it is relocatable if itis assigned the value of an absolute expression it is absolute The linker supports the C language operators listed in Table 7 1 in order of precedence Operators in the same group have the same precedence Besides the operators listed in Table 7 1 the l
369. otorg option Use either memwidth 8 or memwidth 16 For example the command file in Figure 10 8 allows you to boot the text section of abc out from a byte wide EPROM at location 0x8000 Figure 10 8 Sample Command File for Booting From a C54x EPROM abc out input file o abc i output file i Intel format memwidth 8 8 bit memory romwidth 8 outfile is bytes not words bootorg 0x8000 external memory boot f SECTIONS text BOOT 10 34 Controlling the ROM Device Address 10 10 Controlling the ROM Device Address The hex conversion utility output address field corresponds to the ROM device address The EPROM programmer burns the data into the location specified by the hex conversion utility output file address field The hex conversion utility offers some mechanisms to control the starting address in ROM of each sec tion and or to control the address index used to increment the address field However many EPROM programmers offer direct control of the location in ROM in which the data is burned 10 10 1 Controlling the Starting Address Depending on whether or not you are using the boot loader the hex conversion utility output file controlling mechanisms are different Non boot loader mode The address field of the hex conversion utility output file is controlled by the following mechanisms listed from low to high priority 1 Thelinker command file By default the address f
370. ough 15 Figure 10 7 shows how the ROMS directive partitions the infile out file into four output files Figure 10 7 The infile out File From Example 10 1 Partitioned Into Four Output Files COFF File Output Files infile out EPROM1 rom4000 b0 rom4000 b1 04000h 04000h org text 0487Fh 04880h 05B80h Oh a E 0633Fh 05FFFh 06700h width 8 bits len 2000h 8K EPROM2 07C7Fh rom6000 b0 rom6000 b1 06000h V 06340h memwidth 16 bits 06700h 07C80h 07FFFh 10 20 The ROMS Directive 10 5 3 Creating a Map File of the ROMS Directive The map file specified with the map option is advantageous when you use the ROMS directive with multiple ranges The map file shows each range its parameters names of associated output files and a list of contents section names and fill values broken down by address Following is a segment of the map file resulting from the example in Example 10 1 Example 10 2 Map File Output From Example 10 1 Showing Memory Ranges 00004000 00005fff Page 0 Width 8 EPROM1 OUTPUT FILES rom4000 b0 bO0 b7 rom4000 b1 b8 b15 CONTENTS 00004000 0000487 text 00004880 00005b7 FILL 00000000 00005580 00005fff data 00006000 00007fff Page 0 Width 8 EPROM2 OUTPUT FILES rom6000 b0 bO b7 rom6000 b1 b8 b15 CONTENTS 00006000 0000633f data 00006340 000066ff FILL 000000ff 00006700
371. ource statement number an SPC value the object code assembled and the source statement A source statement may produce more than one word of object code The assembler lists the SPC value and object code on a separate line for each additional word Each additional line is listed immediately following the source statement line Field 1 Source Statement Number Line Number The source statement number is a decimal The assembler numbers source lines as it encounters them in the source file some state ments increment the line counter but are not listed For example title statements and statements following a nolist are not listed The difference between two consecutive source line numbers indi cates the number of intervening statements in the source file that are not listed Include File Letter The assembler may precede a line with a letter the letter indicates that the line is assembled from an included file Nesting Level Number The assembler may precede a line with a number the number indi cates the nesting level of macro expansions or loop blocks Field 2 Section Program Counter This field contains the section program counter SPC value which is hexadecimal All sections text data bss and named sections maintain separate SPCs Some directives do not affect the SPC and leave this field blank Assembler Description 3 33 Source Listings Field 3 Object Code This field contains the hexadecimal representat
372. outine c intOO defined in boot asm to load and run initializing the C environment and branching to the main function in the applications code The cinit section contains the initialization data and tables for all global or static C symbols that were declared with an initial value i e int x 2 5 Note that the linker handles the cinit section differently than the other sections When the linker encounters a cinit section specified as an output section in the link it automatically Sets the symbol cinit to point to the start of the included cinit section Appends a single word to the end of the section This last word contains a zero that is used to mark the end of the initialization table However if cinit is included as an input section only the linker sets cinit to 1 indicating that no initialization tables were loaded Therefore the C boot routine c_int00 does not attempt to initialize any of the global or static C symbols When linking the cinit section into an output section other than cinit the linker does not perform the automatic functions listed above Therefore these func tions must be implemented explicitly within the linker command file Example C 14 shows a linker command file for a C54xLP device Example 4 Generating a Boot Table for LP Core Devices Example C 14 Linker Command File for a C54xLP Q c54xlp obj L rts lib m c54xlp map o c54xlp out MEMORY PAGE
373. owing RUN apply to run allocation Possible allocation parameters are Binding allocates a section at a specific address text load 0x1000 Memory allocates the section into a range defined in the MEMORY directive with the specified name like ROM or attributes text load ROM Alignment uses the align keyword to specify that the section should start on an address boundary text align 0x80 Toforce the output section containing the assignment to also be aligned assign dot with an align expression For exam ple the following will align bar obj and it will force outsect to align on a 0x40 word boundary SECTIONS outsect bar obj bss align 0x40 Linker Description 7 35 The SECTIONS Directive 7 8 8 1 Binding Blocking uses the block keyword to specify that the section must fit between two address boundaries if the section is too big it will start on an address boundary text block 0x80 Page specifies the memory page to be used see Section 7 11 Overlay Pages on page 7 53 text PAGE 0 For the load usually the only allocation you may simply use a greater than sign and omit the load keyword text ROM text gt ROM text 0x1000 f more than one parameter is used you can string them together as follows text ROM align 16 PAGE 2 Or if you prefer use parentheses for readability text load ROM align 16 page 2 You can supp
374. own in Figure 2 1 One of the linker s functions is to relocate sections into the target memory map this function is called allocation Because most systems contain several types of memory using sections can help you use target memory more effi ciently All sections are independently relocatable you can place any section into any allocated block of target memory For example you can define a sec tion that contains an initialization routine and then allocate the routine into a portion of the memory map that contains ROM Introduction to Common Object File Format 2 3 Sections Figure 2 1 shows the relationship between sections in an object file and a hypothetical target memory Figure 2 1 Partitioning Memory Into Logical Blocks Object File Target Memory p RAM EEPROM How the Assembler Handles Sections 2 3 How the Assembler Handles Sections 2 3 1 The assembler identifies the portions of an assembly language program that belong in a section The assembler has several directives that support this function bss usect text data sect O O O O L The bss and usect directives create uninitialized sections the other directives create initialized sections You can create subsections of any section to give you tighter control of the memory map Subsections are created using the sect and usect directives Subsections are identified with the base section name and a subsection name separated by a colon See
375. perating system conventions Produce a map or listing of the input and output sec tions including holes and place the listing in filename Name the executable output module The default file name is a out The directory or filename must follow operating system conventions Request a quiet run suppress the banner Produce a relocatable output module Strip symbol table information and line number entries from the output module Set C system stack size to size words and define a global symbol that specifies the stack size The de fault size is 1K words Place an unresolved external symbol into the output module s symbol table Specify the output COFF format where nis 0 1 or 2 The default format is COFF2 Displays a message when an undefined output sec tion is created Force rereading of libraries Resolves back refer ences Linker Description 7 7 Linker Options 7 4 4 Relocation Capabilities a and r Options The linker performs relocation which is the process of adjusting all references to a symbol when the symbol s address changes The linker supports two options a and r that allow you to produce an absolute or a relocatable output module If neither a nor r is specified the linker acts as if a is speci fied by default J Producing an Absolute Output Module a Option When you use the a option without the r option the linker produces an absolute executable output module Absolu
376. pport using the archiver to build 6 4 object file defined object format converter defined octal integer constants on chip boot loader boot table 10 28 to 10 34 booting from device peripheral 10 32 booting from EPROM 10 34 booting from the parallel port 10 34 booting from the serial port 10 33 10 36 10 35 controlling ROM device address description 10 28 10 33 to options e summary setting the entry point using the boot loader 10 33 to 10 35 operands defined field immediate addressing 3 19 label local label prefixes source statement format 3 13 operator precedence order 3 26 option directive optional header defined format A 6 options absolute lister 8 3 archiver 6 5 assembler EB 4 cross reference lister 9 3 defined hex conversion utility 10 4 to 10 6 linker 7 6 to 7 20 translator 11 4 order hex conversion utility option 10 15 ordering memory words 10 14 to 10 15 origin MEMORY specification ROMS specification 10 17 to 10 38 Index output executable to hex conversion utility 10 24 linker module defined _F 6 name section allocation to defined F 6 displaying a message rules output listing 4 17 to 4 18 output sections splitting overflow in an expression overlay page defined F 6 described to using the SECTIONS directive 7 55 to overlaying sections to paddr SECTIONS specification 10 23
377. produces a page eject in the listing file The page directive is not printed in the source listing but the assembler increments the line counter when it encounters it Using the page directive to divide the source listing into logical divisions improves program readability This example shows how the page directive causes the assembler to begin a new page of the source listing 4 78 Source file title Page Directive Example E x page Listing file TMS320C54x COFF Assembler Version x xx Copyright c 2001 Texas Instruments Incorporated Page Directive Example PAGE 1 2 3 4 TMS320C54x COFF Assembler Version x xx Copyright c 2001 Texas Instruments Incorporated Page Directive Example PAGE 2 Syntax Description Example Specify Blocking for an Initialized Section Sblock sblock section name section name The sblock directive designates sections for blocking Blocking is an address alignment mechanism similar to page alignment but weaker A blocked section is guaranteed to not cross a page boundary 128 words if it is smaller than a page or to start on a page boundary if it is larger than a page This directive allows specification of blocking for initialized sections only not uninitialized sections declared with usect or the bss directives The section names may optionally be enclosed in quotes This example designates the text and data sections f
378. ption by at least one space DD Options with multicharacter names must be spelled exactly as shown in this document no abbreviations are allowed Options are not affected by the order in which they are used The exception to this rule is the q option which must be used before any other options filename names a COFF object file or a command file for more informa tion on command files see Section 10 3 Command Files on page 10 7 Hex Conversion Utility Description 10 3 Invoking the Hex Conversion Utility Table 10 1 Hex Conversion Utility Options a General options The general options control the overall operation of the hex conversion utility Option Description Page byte Number bytes sequentially 10 37 map filename Generate a map file o filename Specify an output filename q Run quietly when used it must appear before 10 7 other options b Image options The image options create a continuous image of a range of target memory Option Description Page fill value Fill holes with value 10 27 image Specify image mode 10 26 zero Reset the address origin to zero 10 36 c Memory options The memory options configure the memory widths for your output files Option Description Page memwidth value Define the system memory word width default 16 10 10 bits order LS MS Specify the memory word ordering 10 14 romwidth value Specify the ROM device width default
379. ption or by the ROMS directive origin For another example see Section C 4 Example 3 Generating a Boot Table for Non LP Core Devices on page C 10 Description of the Object Formats 10 11 Description of the Object Formats The hex conversion utility converts a COFF object file into one of five object formats that most EPROM programmers accept as input ASCII Hex Intel MCS 86 Motorola S Extended Tektronix or TI Tagged Table 10 3 specifies the format options _j If you use more than one of these options the last one you list overrides the others The default format is Tektronix x option Table 10 3 Options for Specifying Hex Conversion Formats Address Default Option Format Bits Width a ASCII Hex 16 8 i Intel 32 8 m1 Motorola S1 16 8 m2 or m Motorola S2 24 8 m3 Motorola S3 32 8 TI Tagged 16 16 X Tektronix 32 8 Address bits determine how many bits of the address information the format supports Formats with 16 bit addresses support addresses up to 64K only The utility truncates target addresses to fit in the number of available bits The default width determines the default output width You can change the default width by using the romwidth option or by using the romwidth param eter in the ROMS directive You cannot change the default width of the TI Tagged format which supports a 16 bit width only Hex Conversion Utility Description 10 39 Description of the Object F
380. ptional hyphen You must use one of the following commands when you invoke the archiver but you can use only one command per invocation Valid archiver commands are adds the specified files to the library This command does not replace an existing member that has the same name as an added file it simply appends new members to the end of the archive deletes the specified members from the library replaces the specified members in the library If you don t specify filenames the archiver replaces the library mem bers with files of the same name in the current directory If the specified file is not found in the library the archiver adds it instead of replacing it prints a table of contents of the library If you specify file names only those files are listed If you don t specify any filenames the archiver lists all the members in the speci fied library extracts the specified files If you don t specify member names the archiver extracts all library members When the archiver extracts a member it simply copies the mem ber into the current directory it doesn t remove it from the library option libname filename q S V Invoking the Archiver tells the archiver how to function Specify as many of the following options as you want quiet suppresses the banner and status messages prints a list of the global symbols that are defined in the library This option is valid only with the a r an
381. put file abs500 is the command that invokes the absolute lister options identifies the absolute lister options that you want to use Options are not case sensitive and can appear anywhere on the command line following the command Precede each option with a hyphen The absolute lister options are as follows e enables you to change the default naming conventions for filename extensions on assembly files C source files and C header files The three options are listed below Lj ea asmext for assembly files default is asm ec cext for C source files default is c DD eh hext for C header files default is h The in the extensions and the space between the option and the extension are optional q quiet suppresses the banner and all progress infor mation input file names the linked object file If you do not supply an extension the absolute lister assumes that the input file has the default extension out If you do not supply an input filename when you invoke the absolute lister the absolute lister will prompt you for one The absolute lister produces an output file for each file that was linked These files are named with the input filenames and an extension of abs Header files however do not generate a corresponding abs file Assemble these files with the a assembler option as follows to create the absolute listing asm500 a filename abs The e options affect both the interpret
382. py and include directives can be nested within a file being copied or included The assembler limits nesting to 32 levels the host operating system may set additional restrictions The assembler precedes the line numbers of copied files with a letter code to identify the level of copying An A indicates the first copied file B indicates a second copied file etc Example 1 copy asm source file Space 29 COPY byte asm Back in original file pstring done Read Source File copy include In this example the copy directive is used to read and assemble source state ments from other files then the assembler resumes assembling into the cur rent file The original file copy asm contains a copy statement copying the file byte asm When copy asm assembles the assembler copies byte asm into its place in the listing note listing below The copy file byte asm contains a copy statement for a second file word asm When it encounters the copy statement for word asm the assembler switches to word asm to continue copying and assembling Then the assembler returns to its place in byte asm to continue copying and assembling After completing assembly of byte asm the assembler returns to copy asm to assemble its re maining statement byte asm word asm first copy file second copy file In byte asm In word asm byte 32 14 A word OABCDh 56q copy word asm Back in byte asm byte 67h 3q Lis
383. quired after assignment Description There is a syntax error in the command file statement ignored Description There is a syntax error in an expression symbol referencing errors not built Description Symbol references could not be resolved Therefore an object module could not be built symbol from file being redefined Description A defined symbol is redefined in an assignment statement too few symbol names in string table for archive n Description The archive file may be corrupt Action If the input file is corrupt try recreating the archive Linker Error Messages too many arguments use a command file Description You used more than ten arguments on a command line or in response to prompts too many i options 7 allowed Action More than seven i options were used Additional search di rectories can be specified with a C DIR or A DIR environ ment variable type flags for redefined Description More than one section type is supplied for a section Note that type COPY has all ofthe attributes of type DSECT so DSECT need not be specified separately type flags not allowed for GROUP or UNION Description A type is specified for a section in a group or union Special section types apply to individual sections only u does not specify a legal symbol name Description The u option did not specify a legal symbol name that exists in one of the files that you are linking unexpect
384. r J A character string enclosed in double quotes Each character in a string represents a separate value The value operand can be either an absolute or relocatable expression If an expression is relocatable the assembler generates a relocation entry that re fers to the appropriate symbol the linker can then correctly patch relocate the reference This allows you to initialize memory with pointers to variables or with labels You can use up to 100 values but they must fit on a single source statement line If you use a label it points to the first word that is initialized When you use the directives in a struct endstruct sequence they define a member s size they do not initialize memory For more information about Struct endstruct see Section 4 9 Assembly Time Symbol Directives on page 4 21 Initialize Long Word long ulong xlong Example This example shows how the long and xlong directives initialize double words 1 000000 0000 DAT1 long OABCDh A 100h g o 000001 ABCD 000002 0000 000003 0141 000004 0000 000005 0067 000006 0000 000007 006F 2 000008 0000 xlong DAT1 OAABBCCDDh 000009 0000 00000a AABB 00000b CCDD 3 00000c DAT2 Assembler Directives 4 65 loop break endloop Assign Character Strings to Substitution Symbols Syntax Description Example 4 66 loop well defined expression break well defined expression endloop Three directives enable you to repeate
385. r the symbol name Unlike symbolic constants substitution symbols can be redefined A string can be assigned to a substitution symbol anywhere within a program for example asg errct AR2 register 2 asg AE INC indirect auto increment agg DEC indirect auto decrement When you are using macros substitution symbols are important because macro parameters are actually substitution symbols that are assigned a macro argument The following code shows how substitution symbols are used in macros add2 macro ADDRA ADDRB add2 macro definition LD ADDRA A ADD ADDRB A STL A ADDRB endm add2 invocation add2 LOC1 LOC2 add LOC1 argument to a second argument LOC2 instructions for expanded macro LD LOC1 A ADD LOC2 A STL A LOC2 For more information about macros see Chapter 5 Macro Language Assembler Description 3 21 Symbols 3 8 6 Local Labels Local labels are special labels whose scope and effect are temporary A local label can be defined in two ways Jg n where nis a decimal digit in the range of 0 9 For example 4 and 1 are valid local labels D name where name is any legal symbol name as described above The assembler replaces the question mark with a period followed by a unique number When the source code is expanded you will not see the unique number in the listing file Your label appears with the question mark as it did in the macro definition You cannot d
386. r Two 8 B EPROMS To illustrate precisely how the utility performs the conversion specify the map option Although not required the map option generates useful information about the output The resulting map is shown in Example C 4 Example C 4 Map File Resulting From Hex Command File in Example C 3 on page C 5 Ck Ck ck ck Ck ck ck ck ck ce ck ck C Sk ck Ck Sk ck Ck ck ck Ck ck ck ck ck KKK Ck ck ck kk ck kk KK KKK KKK KKK KKK KKK TMS320C54x COFF Hex Converter Version x xx Fri Oct 11 15 10 53 2001 INPUT FILE NAME test out OUTPUT FORMAT Intel PHYSICAL MEMORY PARAMETERS Default data width 16 Default memory width 16 Default output width 8 OUTPUT TRANSLATION MAP 00000000 0000ffff Page 0 Memory Width 16 ROM Width 8 EPROM OUTPUT FILES low8 bit b0 b7 upp8 bit b8 b15 CONTENTS 00000010 00000017 outsec Data Width 2 Hex Conversion Utility Examples C 7 Example 2 Avoiding Holes With Multiple Sections C 3 Example 2 Avoiding Holes With Multiple Sections When the memory width is less than the data width holes may appear at the beginning of a section or between sections This is dueto multiplication of the load address by a correction fa
387. re internal register structure data and program addressing and the instruction pipeline Also includes development support information parts lists and design considerations for using the XDS510 emulator TMS320C54x DSP Reference Set Volume 2 Mnemonic Instruction Set literature number SPRU172 describes the TMS320C54x digital signal processor mnemonic instructions individually Also includes a summary of instruction set classes and cycles TMS320C54x DSP Reference Set Volume 3 Algebraic Instruction Set literature number SPRU179 describes the TMS320C54x digital signal processor algebraic instructions individually Also includes a summary of instruction set classes and cycles TMS320C54x DSP Reference Set Volume 4 Applications Guide literature number SPRU173 describes software and hardware applications for the TMS320C54x digital signal processor Also includes development support information parts lists and design considerations for using the XDS510 emulator Code Composer User s Guide literature number SPRU328 explains how to use the Code Composer development environment to build and debug embedded real time DSP applications Code Composer Studio TMS320C54x and C54x are trademarks of Texas Instruments Incorporated Contents Intiroduction i eriei ei a aE a a a E E bees wokes estweMened a O a E 1 1 Provides an overview of the software development tools 1 1 Software Development Tools Overview pp 1 2
388. recognizes ABC Abc and abc as three unique symbols You can override case sensitivity with the c assembler option A symbol is valid only during the assembly in which it is defined unless you use the global directive to declare it as an external symbol Symbols used as labels become symbolic addresses associated with loca tions in the program Labels used locally within a file must be unique Mnemonic opcodes and assembler directive names without the prefix are valid label names Labels can also be used as the operands of global ref def or bss direc tives for example global labell label2 NOP ADD labell B B label2 3 8 2 Symbolic Constants Symbols can be set to constant values By using constants you can equate meaningful names with constant values The set and struct tag endstruct directives enable you to set constants to symbolic names Symbolic constants cannot be redefined The following example shows how these directives can be used K Set 1024 constant definitions maxbuf set 2 K value set 0 delta set 1 item Struce item structure definition int value constant offsets value 0 int delta constant offsets delta 1 i len endstruct array tag item array declaration bss array i len K The assembler also has several predefined symbolic constants these are discussed in the next section Assembler Description 3 19 Symbols 3 8 8 Defining Symbolic Constants d Op
389. red Offset expression value out of range Power of 2 required next larger power of 2assumed Section Name is limited to 8 characters Section name name truncated to 8 chars Set value must be 0 or 1 Shift value out of range Status bit value out of range Status register must be 0 or 1 String is too long will be truncated Valid values are 1 and 2 Value values to xxx are nnn Value truncated Value truncated to x bit width Value truncated to byte size Value out of range Description These are warnings about truncated values The expression given was too large to fit within the instruction opcode or the required number of bits Action Check the source to make sure the result will be acceptable or change the source if an error has occurred Address expression will wrap around Expression will overflow value truncated Description These are warnings about arithmetic expressions The assembler has done a calculation that will produce the indicated result which may or may not be acceptable Action Verify the result will be acceptable or change the source if an error has occurred Assembler Error Messages D 17 Assembler Error Messages Incorrect size for the type sym for function name required before func Description This is a warning about problems with symbolic debugging directives A sym directive defining the function does not appear before the func directive Action Correct the source access only a
390. referenced them and their final values Glossary data One of the default COFF sections The data section is an initialized section that contains initialized data You can use the data directive to assemble code into the data section directives Special purpose commands that control the actions and functions of a software tool as opposed to assembly language instruc tions which control the actions of a device emulator A hardware development system that emulates TMS320C54x operation entry point The starting execution point in target memory executable module An object file that has been linked and can be executed in a TMS320C54x system expression 4A constant a symbol or a series of constants and symbols separated by arithmetic operators external symbol A symbol that is used in the current program module but is defined in a different program module field Forthe TMS320C54x a software configurable data type whose length can be programmed to be any value in the range of 1 16 bits file header A portion of a COFF object file that contains general information about the object file Such as the number of section headers the type of system the object file can be downloaded to the number of symbols in the symbol table and the symbol table s starting address global A kind of symbol that is either 1 defined in the current module and accessed in another or 2 accessed in the current module but defined in a
391. rements for the EPROM programmer and options that describe the EPROM memory system For Example 4 assume that the EPROM programmer has only one require ment that the hex file be in Intel format In the EPROM memory system illustrated in Figure C 4 on page C 17 the EPROM system memory width is 8 bits and the physical ROM width is 8 bits The following options are selected to reflect the requirements of the system Option Description Create Intel format memwidth 8 Set EPROM system memory width to 8 romwidth 8 Set physical ROM width to 8 Because the application requires the building of a boot table for parallel boot mode the following options must be selected as well Option Description boot Create a boot load table bootorg 0x0000 Place boot table at address 0x0000 Hex Conversion Utility Examples C 21 Example 4 Generating a Boot Table for LP Core Devices Example C 16 Hex Command File for Converting a COFF File c54xlp out Input COFF file i Select Intel format oy map c54xlp mxp Name hex utility map file f o c54xlp hex Name the hex output file memwidth 8 Set EPROM system memory width wf romwidth 8 Set physical ROM width boot Make all sections bootable E bootorg 0x0000 Place boot table in EPROM starting at address 0x0000 ROMS PAGE 0 ROM origin 0x0000 length 0x20000 In Example 4 memory width and ROM width are the sa
392. rg SERIAL on the command line or in a command file To boot a C54x from one of its parallel ports specify bootorg PARALLEL l m Note On Chip Boot Loader Concerns Possible memory conflicts When you boot from a device peripheral the boot table is not actually in memory it is being received through the device peripheral However as explained in Step 3 on page 10 31 a memory address is assigned If the table conflicts with a nonboot section put the boot table on a different page Use the ROMS directive to define a range on an unused page and the bootpage option to place the boot table on that page The boot table will then appear to be at location 0 on the dummy page Why the System Might Require an EPROM Format for a Peripheral Boot Loader Address In a typical system a parent processor boots a child processor through that child s peripheral The boot loader table itself may occupy space in the memory map ofthe parent processor The EPROM format and ROMS directive address correspond to those used by the parent processor not those that are used by the child LLLL P 10 9 5 Setting the Entry Point for the Boot Table 10 32 After completing the boot load process execution starts at the default entry point sp
393. ries 5 4 MacroLibraries One way to define macros is by creating a macro library A macro library is a collection of files that contain macro definitions You must use the archiver to collect these files or members into a single file called an archive Each member of a macro library contains one macro definition The files in a macro library must be unassembled source files The macro name and the member name must be the same and the macro filename s extension must be asm For example Macro Name Filename in Macro Library simple simple asm add3 add3 asm You can access the macro library by using the mlib assembler directive de scribed on page 4 68 The syntax is mlib macro library filename When the assembler encounters the mlib directive it opens the library and creates a table of the library s contents The assembler enters the names of the individual members within the library into the opcode tables as library entries this redefines any existing opcodes or macros that have the same name If one of these macros is called the assembler extracts the entry from the library and loads it into the macro table The assembler expands the library entry in the same way it expands other macros You can control the listing of library entry expansions with the mlist directive For more information about the mlist directive see Section 5 8 Formatting the Output Listing on page 5 21 Only macros that are actually called
394. rithmetic type is required but not present Action Correct the source per the error message text Assembler Error Messages D 9 Assembler Error Messages Absolute operands required for FP operations Floating point divide by zero Floating point overflow Floating point underflow Floating point expression required Illegal floating point expression Invalid floating point operation Description These are errors about floating point expressions A float ing point expression was used where an integer expressionis required an integer expression was used where a float ing point expression is required or a floating point value is invalid Action Correct the source per the error message text Cannot equate an external symbol to an external Cannot redefine this section name Cannot tag an undefined symbol Empty structure or union definition Illegal structure or union tag Missing closing F for repeat block Redefinition of sym attempted Structure tag can t be global Symbol can t be defined in terms of itself Symbol expected Symbol expected in label field Symbol sym has already been defined Symbol sym is not defined in this source file Symbol sym is operand to both ref and def Structure union member sym not found The following symbols are undefined Union member previously defined Union tag can t be global Description These are errors about general symbols An attempt was made to redefine a symbol or to defi
395. roduction to Common Object File Format The assembler and linker create object files that can be executed by a TMS320C54x device The format for these object files is called common object file format COFF COFF makes modular programming easier because it encourages you to think in terms of blocks of code and data when you write an assembly language program These blocks are known as sections Both the assembler and the linker provide directives that allow you to create and manipulate sections This chapter provides an overview of COFF sections For additional information see Appendix A Common Object File Format which explains the COFF structure Topic Page 2 1 SCORERS IV pes nn uu m md NE Me p 2 2 SSlonmeiaasoaaacosnaabbobcnaaooobbouaoaoaaaaaoaaaaaoaaaoaoooaoa b 3 2 3 How the Assembler Handles Sections p 5 2 4 How the Linker Handles Sections es 2 13 2 SEEHelocation per 2 6 Runtime Relocation oe ee ee ee 2 7 Loadingia Program sss en a tx mte 2 8 Symbolsina GOFFFile ee RENI 2 21 2 1 COFF File Types 2 1 COFFFile Types The following types of COFF files exist J COFFO COFF1 COFF2 Each COFF file type has a different header format The data portions of the COFF files are identical For details about the COFF file structure see Appendix A Common Object File Format The TMS320C54x assembler and C compiler create COFF2 files The linker can rea
396. ros and blocks limits the listing of byte directives to one line turns off the listing of certain directives same effect as drnolist limits the listing of half and short directives to one line limits the listing of long directives to one line turns off macro expansions in the listing z2r rog turns off listing performs nolist Assembler Directives 4 17 Directives That Format the Output Listing turns on listing performs list resets the B M T and W options limits the listing of string directives to one line limits the listing of word directives to one line z4m0 produces a symbol cross reference listing You can also obtain a cross reference listing by invoking the assembler with the x option The page directive causes a page eject in the output listing The sslist and ssnolist directives allow and suppress substitution symbol expansion listing These directives are useful for debugging the expansion of substitution symbols The tab directive defines tab size The title directive supplies a title that the assembler prints at the top of each page The width directive controls the page width of the listing file You can use this directive to adjust listings for various output devices Directives That Reference Other Files 4 7 Directives That Reference Other Files These directives supply information for or about other files The copy and include directives tell the assem
397. ross Reference Lister Development Flow Step 1 Assembler source file Cross reference lister Cross reference listing First invoke the assembler with the x option This option produces a cross reference table in the listing file and adds to the object file cross reference information By default the assembler cross references only global sym bols If you use the s option when invoking the assembler it will cross reference local variables as well Link the object file obj to obtain an execut able object file out Invoke the cross reference lister The follow ing section provides the command syntax for invoking the cross reference lister utility Invoking the Cross Reference Lister 9 2 Invoking the Cross Reference Lister To use the cross reference utility the file must be assembled with the correct options and then linked into an executable file Assemble the assembly lan guage files with the x option This option creates a cross reference listing and adds cross reference information to the object file By default the assembler cross references only global symbols but if assem bler is invoked with the s option local symbols are also added Link the object files to obtain an executable file To invoke the cross reference lister enter the following xref500 options input filename output filename xref500 options input filename output filename is the command that inv
398. rror that occurs in your code first A single error condition can cause a cascade of spurious errors If you have received an assembler error message use this appendix to find possible solutions to the problem you encountered First locate the error message class number Then locate the error message that you encountered within that class Each class number has an alphabetical list of error messages that are associated with it Each class has a Description of the problem and an Action that suggests possible remedies D 1 Assembler Error Messages D 2 Attempt to nest repeat block Comma required to separate arguments Comma required to separate parameters Commas must separate directive elements Illegal combination of shift operands Illegal identifier after keyword unsigned Illegal instruction Illegal keyword Illegal repeat block open check delay slot Illegal repeat block open missing repeat Illegal shift for parallel operation Left parenthesis expected Left parenthesis is missing Matching right parenthesis is missing Missing comma Missing left parenthesis Missing opening brace Missing right parenthesis Missing right parenthesis for value specification Missing right quote of string constant No matching right parenthesis Open repeat block at EOF Right parenthesis expected Syntax Error Syntax requires parentheses Unrecognized character type Description These are errors about general syntax The required s
399. rs relocatable symbols in expressions reserved words setting to a constant value 3 19 statement number that defines 3 37 substitution unresolved used as labels value assigned syntax assignment statements 7 62 source statement Sysmem section SYSMEM SIZE system stack t archiver command hex conversion utility option 10 43 tab directive 4 18 4 18 4 89 tag defined F 8 tag directive target memory defined F 8 target width tcsr hex conversion utility option 10 29 Tektronix object format 10 44 text directive 2 5 4 9 linker d text e E A 3 defined TI Tagged x format title directive 4 18 esl translator described development flow 11 3 input files invoking limitations trta hex conversion utility option 10 29 type entry u assembler opion 4 linker option 7 18 ubyte directive 4 12 uchar directive E uhalf directive E sd 58 uint directive 4 1 ulong directive 4 13 4 64 unconfigured memory defined described DSECT type underflow in an expression Index uninitialized sections 2 5 to 2 6 bss 2 6 14 30 2 6 defined re described initialization E specifying a run address 7 45 4 95 usect defined 8 linker directive 7 48 to 7 52 union tag defined symbolic debugging directives union directive unsigned defined Usect directive compatibility with C1x C2x C2xx C5x
400. rst The TMS320C54x Assembly Language Tools User s Guide tells you how to use these assembly language tools D D UD D D C Assembler Archiver Linker Absolute lister Cross reference lister Hex conversion utility How to Use This Manual The goal of this book is to help you learn how to use the Texas Instruments assembly language tools specifically designed for the TMS320C54x DSPs This book is divided into four parts Lj Introductory information gives you an overview of the assembly language development tools and also discusses common object file format COFF which helps you to use the TMS320C54x tools more efficiently Read Chapter 2 Introduction to Common Object File Format before using the assembler and linker Assembler description contains detailed information about using the assembler This section explains how to invoke the assembler and discusses source statement format valid constants and expressions assembler output and assembler directives It also describes macro elements Additional assembly language tools describes in detail each of the tools provided with the assembler to help you create assembly language source files For example Chapter 7 explains how to invoke the linker how the linker operates and how to use linker directives Chapter 10 explains how to use the hex conversion utility Notational Conventions Notational Conventions Reference material provides supplementary information Th
401. ry 00000h 00000h 0005Fh mE 00060h SCRATCH 0007Fh 01C00h OFFFFh 00080h ONCHIP on chip RAM 0107Fh 01080h 00C00h on chip ROM Linker Description 7 31 The SECTIONS Directive 7 8 The SECTIONS Directive The SECTIONS directive D Describes how input sections are combined into output sections Defines output sections in the executable program Specifies where output sections are placed in memory in relation to each other and to the entire memory space Lj Permits renaming of output sections Refer to Section 2 4 How the Linker Handles Sections on page 2 13 for details on how the linker handles sections Refer to Section 2 5 Helocation on page 2 16 for information on the relocation of sections Refer to subsection 2 3 4 Subsections on page 2 9 for information on defining subsections subsections allow you to manipulate sections with greater precision 7 8 1 Default Configuration If you do not specify a SECTIONS directive the linker uses a default algorithm for combining and allocating the sections Section 7 12 Default Allocation Algorithm on page 7 58 describes this algorithm in detail 7 8 2 SECTIONS Directive Syntax The SECTIONS directive is specified in a command file by the word SECTIONS uppercase followed by a list of output section specifications enclosed in braces The general syntax for the SECTIONS directive is SECTIONS i name property property property name
402. ry for macro name Bad archive name Can t read a line from archive entry library name macro library not found library name is not in archive format Description These are errors about macro library accessing A problem was encountered reading from or writing to a macro library archive file It is likely that the creation of the archive file was not done properly Action Make sure that the macro libraries are unassembled assem bler source files Also make sure that the macro name and member name are the same and the extension of the file is asm Can t use g on assembly code with line directives Illegal structure union member No structure union currently open sym not allowed inside structure union Description These are errors about the illegal use of symbolic debugging directives a symbolic debugging directive is not used in an appropriate place Action Correct the source per the error message text Assembler Error Messages Control flow change in delayed branch slot Instructions not permitted in structure union definitions Parallel operator without instruction Too many words in delayed branch slot Description These are errors about parallel or branch instructions These errors are normally target specific Action Correct the source per the error message text Too many parallel instructions Description This error is caused by having too many instructions in parallel Action Checkthe source for parallel instruction
403. ry range It can be entered as origin org or o The associated value must be a decimal octal or hexadecimal constant If you omit the origin value the origin defaults to 0 The following table summarizes the notation you can use to specify a decimal octal or hexadecimal constant Constant Notation Example Hexadecimal Ox prefix or h suffix 0x77 or 077h Octal 0 prefix 077 Decimal No prefix or suffix 77 specifies the length of a memory range as the physical length of the ROM device It can be entered as length len or The value must be a decimal octal or hexadecimal constant If you omit the length value it defaults to the length of the entire address space specifies the physical ROM width of the range in bits see subsection 10 4 4 ROM Wiath on page 10 11 Any value you specify here overrides the romwidth option The value must be a decimal octal or hexadecimal constant that is a power of 2 greater than or equal to 8 specifies the memory width of the range in bits see subsection 10 4 3 Memory Width on page 10 10 Any value you specify here overrides the memwidth option The value must be a decimal octal or hexadecimal constant that is a power of 2 greater than or equal to 8 When using the memwidth parameter you must also specify the paddr parameter for each section in the SECTIONS directive specifies a fill value to useforthe range In image mode the hex conversion utility uses this value to fill any ho
404. s The assembler assembles each section as if it started at 0 and the linker relocates it to the address at which it loads and runs For some applications it is desirable to have a section load at one address and run at a different address For example you may wish to load a block of perfor mance critical code into slower off chip memory to save space and then move the code to high speed on chip memory to run it Such a section is assigned two addresses at link time a load address and a run address All labels defined in the section are relocated to refer to the run time address so that references to the section such as branches are correct when the code runs The label directive creates a special label that refers to the loadtime address This function is useful primarily to designate where the section was loaded for purposes of the code that relocates the section This example shows the use of a loadtime address label Sect EXAMP label EXAMP LOAD load address of section START run address of section code FINISH run address of section end label EXAMP END load address of section end For more information about assigning runtime and loadtime addresses in the linker see Section 7 9 Specifying a Section s Runtime Address on page 7 44 Syntax Description Example Set Listing Page Size length width Jength page length Width page width The length directive sets the page length of the output
405. s but do not align on long word boundary Initialize one or more 32 bit integers but do not align on long word boundary Assembler Directives Page 4 8 N B eo Co ayy R oj LN o T a A co Oo wo O1 T oa A Directives Summary Table 4 1 Assembler Directives Summary Continued c Directives that align the section program counter SPC Mnemonic and Syntax align size in words even d Directives that format the output listing Mnemonic and Syntax drlist drnolist fclist fcnolist length page length list mlist mnolist nolist option B L M R T W X page sslist ssnolist tab size title string Width page width 4 4 Description Align the SPC on a word boundary specified by the parameter the parameter must be a power of 2 or default to page boundary Aligns to word 1 even 2 etc Align the SPC to a word boundary Description Enable listing of all directive lines default Suppress listing of certain directive lines Allow false conditional code block listing default Suppress false conditional code block listing Set the page length of the source listing Restart the source listing Allow macro listings and loop blocks default Suppress macro listings and loop blocks Stop the source listing Select output listing options Eject a page in the source listing Allow expanded substitution symbol listing Suppress expanded substitutio
406. s in a C C source file The filename is the name of the file that contains the original C C source program The first 14 characters of the filename are sig nificant You can also use the file directive in assembly code to provide a name in the file and improve program readability In the following example the filename text c contained the C source that pro duced this directive file text c Symbolic Debugging Directives B 3 func endfunc Define a Function Syntax Description Example func beginning line number endfunc ending line number The func and endfunc directives specify the beginning and end of a C C function The ine numbers are optional they specify the location in the source file where the function is defined Function definitions cannot be nested Following is an example of C source that defines a function and the resulting assembly language code C source power x n Beginning of a function int x n int LE p p 1 for i 1 i lt n i p p x return p End of function Oo COO 10 O1 CO PO ES CD NO NO PO PO PO PO PO PO FH al OY 015 CQ ND P5 CO xo 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 000000 000000 000001 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 0 C63 0 63 OOO 0 002 003 004 005 006 007 008
407. s Reference Listings A cross reference listing shows symbols and their definitions To obtain a cross reference listing invoke the assembler with the option or use the option directive The assembler will append the cross reference to the end of the source listing Note that when the assembler generates a cross reference listing for an assembly file that contains include directives it keeps a record of the include file and line number in which a symbol is defined referenced It does this by assigning a letter reference A B C etc for each include file The letters are assigned in the order in which the include directives are encountered in the assembly source file Example 3 5 Sample Cross Reference Listing LABEL VALUE DEFN REF 0002 14 2 0004 15 2 0006 16 2 REF 4 14 REF 4 15 REF 4 16 0000 13 2 0002 24 3 0000 23 3 0006 26 3 0004 27 0000 34 13 Definition Reference column contains each symbol that was defined or referenced during the assembly column contains a hexadecimal number which is the value assigned to the symbol ora name that describes the symbol s attributes A value may also be followed by a character that describes the symbol s attributes Table 3 4 lists these char acters and names DEFN column contains the statement number that defines the symbol This column is blank for undefined symbols REF column lists the line numbers of s
408. s are initialized at load time This enhances performance by reducing boot time and by saving memory used by the initialization tables You must use a smart loader i e one capable of initializing variables to take advantage of the RAM model of autoinitialization When you use cr the linker marks the cinit section with a special attri bute This attribute tells the linker notto load the cinit section into memory The linker also sets the cinit symbol to 1 this tells the C C boot routine thatinitialization tables are not present in memory Thus no runtime initial ization is performed at boot time When the program is loaded the loader must be able to B Detect the presence of the cinit section in the object file m Detect the presence of the attribute that tells it not to copy the cinit section m Understand the format of the initialization tables This format is described in the TMS320C54x Optimizing C C Compiler User s Guide The loader then uses the initialization tables directly from the object file to initialize variables in bss Linker Description 7 73 Linking C C Code Figure 7 7 illustrates the RAM autoinitialization model Figure 7 7 RAM Model of Autoinitialization ObjectFile Memory J ROM Model c option Variables are initialized at runtime The cinit section is loaded into memory along with all the other sections The linker defines a special symbol called cinit that points to the
409. s hierarchical overlays and groupings of sections Example 7 10 shows how two overlays of sections can be grouped together Example 7 10 Nesting GROUP and UNION statements SECTIONS GROUP 1000h run RAM UNION mysecti load ROM d mysect2 loa ROM UNION mysect3 load ROM mysect4 load ROM Given the example linker control file above the linker performs the following allocations The four sections mysect1 mysect2 mysect3 mysect4 are assigned unique non overlapping load addresses in the ROM memory region This assignment is determined by the particular load allocations given for each section Sections mysect1 and mysect2 are assigned the same run address in RAM Sections mysect3 and mysect4 are assigned the same run address in RAM The run addresses of mysect1 mysect2 and mysect3 mysect4 are allo cated contiguously as directed by the GROUP statement subject to alignment and blocking restrictions To refer to groups and unions linker diagnostic messages use the notation GROUP_n UNION n In this notation n is a sequential number beginning at 1 that represents the lexical ordering of the group or union in the linker control file without regard to nesting Groups and unions each have their own counter Linker Description 7 51 Using UNION and GROUP Statements 7 10 4 Checking the Consistency of Allocators The linker checks the cons
410. s it If it does not find this variable it reads the A DIR envi ronment variable and processes it If both variables are set the settings of the processor specific variable are used The processor specific variable is useful when you are using Texas Instruments tools for different processors at the same time If the assembler doesn t find C54X A DIR and or A DIR it will then search for C54X C DIR and C DIR The command for assigning the environment variable is as follows Operating System Enter Windows set A DIR pathname another pathname UNIX setenv A DIR pathname another pathname Assembler Description 3 9 Naming Alternate Files and Directories for Assembler Input 3 10 The pathnames are directories that contain copy include files or macro libraries You can separate the pathnames with a semicolon or with blanks In assembly source you can use the copy include or mlib directive without specifying path information If the assembler doesn t find the file in the direc tory that contains the current source file or in directories named by i it searches the paths named by the environment variable For example assume that a file called source asm contains these statements COPY copyl asm COPY copy2 asm Assume that the files are stored in the following directories Windows c tools files copy1 asm c dsys copy2 asm UNIX tools files copy1 asm dsys copy2 asm You could set up the search path with
411. s of assembly language code the second line produces 3 words and the third line produces 10 words Figure A 5 Line Number Entries line number entries symbol table Note that the symbol table entry for XYZ has a field that points back to the beginning of the line number block Because line numbers are not often needed the linker provides an option s that strips line number information from the object file this provides a more compact object module Common Object File Format A 13 Symbol Table Structure and Content A 7 Symbol Table Structure and Content The order of symbols in the symbol table is very important they appear in the sequence shown in Figure A 6 Figure A 6 Symbol Table Contents filename 1 function 1 local symbols for function 1 function 2 local symbols for function 2 filename 2 function 1 local symbols for function 1 static variables defined global symbols undefined global symbols Static variables refer to symbols defined in C C that have storage class static outside any function If you have several modules that use symbols with the same name making them static confines the scope of each symbol to the module that defines it this eliminates multiple definition conflicts Symbol Table Structure and Content The entry for each symbol in the symbol table contains the symbol s Type Value
412. scription The input file may be corrupt Action If the input file is corrupt try reassembling it section at overlays at address Description Two sections overlap and cannot be allocated Action If you are using a linker command file check that MEMORY and SECTIONS directives allow enough room to ensure that no sections overlap section enters unconfigured memory at address Description A section can t be allocated because no existing configured memory area is large enough to hold it Action If you are using a linker command file check that MEMORY and SECTIONS directives allow enough room to ensure that no sections are being placed in unconfigured memory Linker Error Messages E 13 Linker Error Messages section not built Description Most likely there is a syntax error in the SECTIONS directive section not found Description An input section specified in a SECTIONS directive was not found in the input file section won t fit into configured memory Description A section can t be allocated because no configured memory area exists that is large enough to hold it Action If you are using a linker command file check that the MEMORY and SECTIONS directives allow enough room to ensure that no sections are being placed in unconfigured memory seek to failed Description The input file may be corrupt Action If the input file is corrupt try reassembling it semicolon re
413. set 2 Copy globals def ld offset A ld array A globals def global dflag global array global offset The following steps create absolute listings for the files module1 asm and module2 asm Step 1 First assemble module1 asm and module2 asm asm500 modulel asm500 module2 This creates two object files called module1 obj and module2 obj Absolute Lister Description 8 5 Absolute Lister Example Step 2 Next link module1 obj and module2 obj using the following linker command file called bttest cmd File bttest cmd COFF linker command file for linking TMS320C54x modules BOK KKK KK kk kkk kkk kkk kkk k ke ko k k ke koe ke ke e x kk ke ke x e e e e x x f o bttest out Name the output file m bttest map Create an output map J FECKCKCKCk kCkCk Ck kk kk Ck kk Ck kk kk Ck kk k kk k ko kc k koe ke koe ke ke ke ke ke kx x f JP Specify the Input Files f modulel obj module2 0bj ROKK KK KK kk k kk k Ck kk Ck kk kk Ck kk IA ke ko kk ke koe ke ke I x f Specify the Memory Configurations
414. ss assembler does the following E Processes the source statements in a text file to produce a relocatable C54x object file Produces a source listing if requested and provides you with control over this listing Allows you to segment your code into sections and maintain an SPC section program counter for each section of object code Defines and references global symbols and appends a cross reference listing to the source listing if requested Assembles conditional blocks Supports macros allowing you to define macros inline or in a library Assembler Development Flow 3 2 Assembler Development Flow Figure 3 1 illustrates the assembler s role in the assembly language develop ment flow The assembler accepts assembly language source files as input whether created by the assembler itself or by the C C compiler Figure 3 1 Assembler Development Flow C source files pom Assembler source co Macro source files Translator utility aone Macro library Assembler source Library build utility Runtime support library CB Library of object files Linker li Debugging tools Executable COFF file Hex conversion utility ene Absolute lister Assembler Description 3 3 Invoking the Assembler 3 3 Invoking the Assembler To invoke the assembler enter the following
415. sses if they are on different pages Pages are numbered sequentially beginning with O If you do not use the PAGE option the linker allocates initialized sections into PAGE 0 program memory and uninitialized sections into PAGE 1 data memory For example assume that your system can select between two banks of physical memory for data memory space address range AOOh to FFFFh for PAGE 1 and 0AO00h to 2BFF for PAGE 2 Although only one bank can be selected at a time you can initialize each bank with different data This is how you use the MEMORY directive to obtain this configuration Example 7 11 Memory Directive With Overlay Pages 0240h 0D200h 02200h 0D400n 02200h ONCHIF origin PROG origin 0800h length 02C00h length 0AO00n length 02C00h length OAOOh length OVR_ME origin DATA origin OVR_ME origin Linker Description 7 53 Overlay Pages Example 7 11 defines three separate address spaces PAGE 0 defines an area of on chip program memory and the rest of program memory space PAGE 1 defines the first overlay memory area and the rest of data memory space PAGE 2 defines another area of overlay memory for data space Both OVR MEM ranges cover the same address range This is possible because each range is on a different page and therefore represents a different memory space Figure 7 6 shows overlay pages defined by the MEMORY directive in Example 7 11 and the SECTIONS directive in Example 7
416. ssignment statement modifies the SPC denoted by by adding to it assigning a greater value to it or aligning it on an address boundary The operators expressions and syntaxes of assignment statements are described in Section 7 14 Assigning Symbols at Link Time on page 7 62 Creating and Filling Holes The following example uses assignment statements to create holes in output sections SECTIONS outsect filel obj text 100h Create a hole with size 100h words file2 0bj text align 16 Create a hole to align the SPC file3 obj text The output section outsect is built as follows The text section from file1 obj is linked in Lj The linker creates a 256 word hole The text section from file2 obj is linked in after the hole c The linker creates another hole by aligning the SPC on a 16 word boundary DD Finally the text section from file3 obj is linked in All values assigned to the symbol within a section refer to the relative adaress within the section The linker handles assignments to the symbol as if the section started at address 0 even if you have specified a binding address Consider the statement align 16 in the example This statement effectively aligns file3 obj text to start on a 16 word boundary within outsect If outsect is ultimately allocated to start on an address that is not aligned file3 obj text will not be aligned either
417. stitution Symbols as Local Variables in Macros on page 5 13 During macro expansion the assembler passes arguments by variable to the macro parameters The character string equivalent of each argument is assigned to the corresponding parameter Parameters without corresponding arguments are set to the null string If the number of arguments exceeds the number of parameters the last parameter is assigned the character string equivalent of all remaining arguments If you pass a list of arguments to one parameter or if you pass a comma or semicolon to a parameter you must surround these terms with quotation marks At assembly time the assembler replaces the substitution symbol with its corresponding character string then translates the source code into object code Example 5 2 shows the expansion of a macro with varying numbers of arguments Macro Parameters Substitution Symbols Example 5 2 Calling a Macro With Varying Numbers of Arguments Macro definition Parms macro a b c a tas b ib i C OI endm Calling the macro Parms 100 1abel Parms 100 label x y H a 100 A a 100 b label b label o d C XY Parms 100 x Parms 100 200 300 x y a 100 A a 100 200 300 QoS E b x 7 C x c y Parms string ry a string b x 7 c y 5 3 1 Directives That Define Substitution Symbols You can manipulate substitution symbols with the asg and eval directives The asg directi
418. structure attributes to a label Begin union definition U 5 e o gt m co amp eI mj LO A co k gt m os EISE Co 19 oJ 2 1 LO in oo gt o ine Table 4 1 Assembler Directives Summary Continued i Miscellaneous directives Mnemonic and Syntax algebraic c mode emsg string end far mode mmregs mmsg string newblock noremark num remark num sblock section name section name Version value wmsg string Description Directives Summary Page Signifies that the file contains algebraic assembly source Signifies that calls and branches are within the normal 4 35 16 bit address range Send user defined error messages to the output 4 42 device End program 4 44 Signifies that calls and branches are far calls 4 45 Enter memory mapped registers into the symboltable 4 71 Send user defined messages to the output device 4 42 Undefine local labels Identify the beginning of a block of code in which the 4 75 assember will suppress the assembler remark identi fied by num If num is not specified all remarks are suppressed Resume the default behavior of generating the re 4 75 mark s previously suppressed by noremark Designates sections for blocking Specify the device for which processor instructions 4 99 are being built Send user defined warning messages to the output 4 42 de
419. sume assembling into Vars section Xe 22 ok ck ck ck ck ck kk ck ck Ck ck kk ck Ck ck ck ck ck ck ck ck ck Ck ck ck ck ck kk ck ck ck ck kk ok Pk Sk kv kv Sk ko ok 23 000000 sect Vars 24 000000 000D field 13 WORD LE 25 000001 0A00 field OAh BYTE LEN 26 000002 0000 field 10q DWORD LEN 000003 0008 27 Syntax Description Example Define Assembly Time Constant set equ symbol set value symbol equ value The set and equ directives equate a value to a symbol The symbol can then be used in place of a value in assembly source This allows you to equate meaningful names with constants and other values The symbolis a label that must appear in the label field The value must be a well defined expression that is all symbols in the expression must be previously defined in the current source module Undefined external symbols and symbols that are defined later in the module cannot be used in the expression If the expression is relocatable the symbol to which it is assigned is also relocatable The value ofthe expression appears in the object field of the listing This value is not part of the actual object code and is not written to the output file Symbols defined with set or equ can be made externally visible with the def or global directive In this way you can define global absolute constants This example shows how symbols can be assigned with set and equ 1
420. symbols static If you have a symbol that you want to remain global and you use the h option you can use the g option to declare that symbol to be global The g option overrides the effect of the h option for the symbol that you specify The syntax for the g option is g global symbol 7 4 7 Make All Global Symbols Static h Option The h option makes all global symbols defined with the global assembler directive static Static symbols are not visible to externally linked modules By making global symbols static global symbols are essentially hidden This allows external symbols with the same name in different files to be treated as unique The h option effectively nullifies all global assembler directives All symbols become local to the module in which they are defined so no external references are possible For example assume that b1 obj b2 o0bj and b3 obj are related and reference a global variable GLOB Also assume that d1 obj d2 obj and d3 obj are related and reference a separate global variable GLOB By using the h option and partial linking you can link the related files without conflict lnk500 h r bl obj b2 0bj b3 0bj o bpart out lnk500 h r dl obj d2 0bj d3 0bj o dpart out The h option guarantees that bpart out and dpart out do not have global symbols and therefore that two distinct versions of GLOB exist The r option is used to allow bpart out and dpart out to retain their relocatio
421. t directive sign extend defined simulator defined sname SECTIONS specification source file defined ra listings RUNE specifying algebrai instructions 5 8 Index source statement field 3 34 format B 12 to 3 14 number in source listing syntax Space directive SPC aligning by creating a hole to word boundaries assembler symbol assembler s effect on assigning a label to 15 t0 4 16 4 27 10 to 2 12 maximum number of predefined symbol for value associated with labels 3 12 shown in source listings B 33 spc hex conversion utility option 10 29 spce hex conversion utility option 10 29 special section types 7 61 special symbols A 16 to A 17 sslist directive 4 18 4 83 listing control 4 171 4 41 use in macros ssnolist directive 4 18 listing control 4 17 4 41 use in macros stack 7 18 7 19 7 73 stack linker option STACK SIZE Stag symbolic debugging directive static defined symbols variables storage class defined F 7 described string directive compatibility with C1x C2x C2xx C5x limiting listing with option directive 4 76 string functions Index 13 Index string table defined F 7 described stripping line number entries symbolic information struct directive 4 21 structure subsections defined initialized overview substitution symbols arithmetic operations on assigning c
422. t generate code false condi tional blocks Conditional blocks appear in the listing exactly as they appear in the source code fcnolist suppresses the listing of false conditional blocks Only the code in conditional blocks that actually assemble appears in the listing The if elseif else and endif directives do not appear in the listing For false conditional block listing fclist is the default Substitution Symbol Expansion Listing SSlist expands substitution symbols in the listing This is useful for debugging the expansion of substitution symbols The ex panded line appears below the actual source line Ssnolist turns off substitution symbol expansion in the listing For substitution symbol expansion listing ssnolist is the default Directive Listing drlist causes the assembler to print to the listing file all directive lines drnolist suppresses the printing of the following directives in the list ing file asg eval var sslist mlist fclist ssnolist mnolist fcnolist emsg wmsg mmsg length width and break For directive listing drlist is the default Macro Language 5 21 Using Recursive and Nested Macros 5 9 Using Recursive and Nested Macros The macro language supports recursive and nested macro calls This means that you can call other macros in a macro definition You can nest macros up to 32 levels deep When you use recursive macros you call a macro from its own definitio
423. t points to the first initialized word When you use half uhalf short or ushort in a struct endstruct sequence they define a member s size they do not initialize memory For more information about struct endstruct see Section 4 9 Assembly Time Symbol Directives on page 4 21 Example Initialize 16 bit Integer half uhalf short ushort In this example the half directive is used to place 16 bit values 10 1 abc and a into memory short is used to place 16 bit values 8 3 def and b into memory The label STRN has the value 106h which is the location of the first initialized word 1 000000 2 3 000 100 0001 0001 0001 0001 0001 4 0001 0001 0001 0001 0001 0001 01 02 03 04 05 06 07 08 09 0a 0b 000A EFFF 0061 0062 0063 0061 0008 FFFD 0064 0065 0066 0062 Space 100h 16 half 10 1 abc a STRN Short 8 3 def b Assembler Directives 4 55 if elseif else endif Assign Character Strings to Substitution Symbols Syntax Description Jf well defined expression elseif well defined expression else endif The following directives provide conditional assembly The if directive marks the beginning of a conditional block The well defined expression is a required parameter and must be entirely specified on the same line as the directive DD Ifthe expression evaluates to true nonzero the assembler assembles the code that follows t
424. t specify an extension asm is assumed 11 4 Translation Modes 11 4 Translation Modes The translator runs in one of the following modes Literal Keeps the original mnemonic instruction commented out fol lowed by the translated instruction Expansion Expands and preprocesses macro invocations and replaces substitution symbols 11 4 1 Literal Mode t Option When running in the default literal mode t option the translator translates instructions without any preprocessing The translator does not process macros nor does it expand substitution symbols When the translator does not recognize a macro invocation or instruction it prints a message to standard output and does not translate the code The translator creates a file with the same name as the assembler source file and an extension of cnv Figure 11 2 Literal Mode Process Command mnem2alg filename asm Translation Translator Converted file filename cnv 11 4 2 About Symbol Names in Literal Mode In literal mode the translator treats symbol names defined by asg as labels and not as the value they represent In the following example the source code is translated as shown with sym treated as a data memory address Example 11 1 Treatment of Symbol Names in Literal Mode a Source code sym asg AR2 LD sym B b Converted code sym asg AR2 B sym Mnemonic to Algebraic Translator Description 11 5 Translation Modes 11 4 3 E
425. taining algebraic instructions The library build utility builds your own customized C C runtime sup port library Standard runtime support library functions are provided as Source code in rts src and as object code in rts lib The TMS320C54x DSP accepts COFF files as input but most EPROM programmers do not The hex conversion utility converts a COFF object file into Tl tagged Intel Motorola or Tektronix object format The converted file can be downloaded to an EPROM programmer Introduction 1 3 Tools Descriptions The absolute lister accepts linked object files as input and creates abs files as output You assemble abs files to produce a listing that contains absolute rather than relative addresses Without the absolute lister producing such alisting would be tedious and require many manual opera tions The cross reference lister uses object files to produce a cross reference listing showing symbols their definitions and their references in the linked source files The purpose of this development process is to produce a module that can be executed in a C54x target system You can use one of several debugging tools to refine and correct your code Available products include An instruction accurate software simulator D An evaluation module EVM An XDS emulator These debugging tools are accessed within Code Composer Studio For more information see the Code Composer Studio User s Guide Chapter 2 Int
426. tatements that refer ence the symbol A blank in this column indicates that the sym bol was never used Assembler Description 3 37 Cross Reference Listings Table 3 4 Symbol Attributes 3 38 Character or Name Meaning REF External reference global symbol UNDF Undefined Symbol defined in a text section 7 Symbol defined in a data section Symbol defined in a sect section Symbol defined in a bss or usect section For example the following source files a incl0 asm global ABC nop nop b incl1 asm global ABC ld ABC A c incl2 asm global ABC stl A ABC d xref asm start include incl0 asm include incll asm add 10 A include incl2 asm nop nop b start global start bss ABC 2 Cross Reference Listings produce the cross reference listing below The A in the cross reference listing refers to inclO0 asm the first file included B refers to incl1 asm C refers to incl2 asm xref asm PAGE 1 1 000000 start 2 include incl0 asm 3 include inclil asm 4 000003 F000 add 10 A 000004 000A 5 include incl2 asm 6 7 000006 F495 nop 8 000007 F495 nop 9 000008 F073 b start 000009 0000 10 qt global start 12 13 000000 bss ABC 2 xref asm PAGE 2 LABEL VALUE DEFN REF TMS320C540 000001 0 TMS320C541 000000 0 TMS320C542 000000 0 TMS320C543 000000 0 TMS320C544 000000 0 TMS320C545 000000
427. tc Action Check spelling pathname environment variables etc The filename must conform to operating system conventions can t open Description The specified file does not exist Action Check spelling pathname environment variables etc The filename must conform to operating system conventions Linker Error Messages can t open filename Description The specified file does not exist Action Check spelling pathname environment variables etc The filename must conform to operating system conventions can t read Description The file may be corrupt Action If the input file is corrupt try reassembling it can t seek Description The file may be corrupt Action If the input file is corrupt try reassembling it can t write Description Disk may be full or protected Action Check disk volume and protection command file nesting exceeded with file Description Command file nesting is allowed up to 16 levels Linker Error Messages E 5 Linker Error Messages e flag does not specify a legal symbol name Description The e option is not supplied with a valid symbol name as an operand entry point other than c intO0O specified Description For c or cr option only A program entry point other than the value of c intOO was supplied The runtime conventions of the compiler assume that c intOO is the one and only entry point entry point symbol undefined Descrip
428. te files contain no relocation information Executable files contain the following B Special symbols defined by the linker subsection 7 14 4 Symbols Defined by the Linker on page 7 65 describes these symbols E An optional header that describes information such as the program entry point B No unresolved references The following example links file1 obj and file2 obj and creates an absolute output module called a out lnk500 a filel obj file2 obj mA Note aand r Options If you do not use the a or the r option the linker acts as if you specified a lt lt 9 Linker Options Producing a Relocatable Output Module r Option When you use the r option without the a option the linker retains relocation entries in the output module If the output module will be relocated at load time or relinked by another linker execution use r to retain the relocation entries The linker produces a file that is not executable when you use the option without a A file that is not executable does not contain special linker symbols or an optional header The file may contain unresolved refer ences but these references do not prevent creation of an output module The following example links file1 obj and file2 obj and creates a relocat able output module called a out lnk500 r filel obj file2 obj The output file a out can be relinked with other object files or r
429. te memory spaces that occupy the same address ranges In the default model one space is dedicated to program areas while a second is dedicated to data the number of separate address spaces depends on the customized configuration of your chip See the TMS320C54x DSP Reference Set for more information The linker allows you to configure these address spaces separately by using the MEMORY directive s PAGE option In the default model PAGE 0 refers to program memory and PAGE 1 refers to data memory The linker treats these two pages as completely separate memory spaces The C54x supports as many as 255 PAGES but the number available to you depends on the configuration you have chosen Linker Description 7 27 The MEMORY Directive When you use the MEMORY directive be sure to identify a the memory ranges that are available for object code Memory defined by the MEMORY directive is configured memory any memory that you do not explicitly account for with the MEMORY directive is unconfigured memory The linker does not place any part of a program into unconfigured memory You can represent nonexistent memory spaces by simply not including an address range in a MEMORY directive statement The MEMORY directive is specified in a command file by the word MEMORY uppercase followed by a list of memory range specifications enclosed in braces The MEMORY directive in Example 7 3 defines a system that has 4K words of ROM at address COOh in progra
430. ter them in a command file Enter them with hyphens just as you would on the command line Invoking the Linker J Putfilenames and options in a linker command file For example assume that the file linker cmd contains the following lines o link out filel obj file2 0bj Now you can invoke the linker from the command line specify the command filename as an input file 1nk500 linker cmd When you use a command file you can also specify other options and files on the command line For example you could enter 1nk500 m link map linker cmd file3 obj The linker reads and processes a command file as soon as it encounters the filename on the command line so it links the files in this order file1 obj file2 obj and file3 obj This example creates an output file called link out and a map file called link map Linker Description 7 5 Linker Options 7 4 Linker Options 7 6 Linker options control linking operations They can be placed on the command line or in a command file Linker options must be preceded by a hyphen The order in which options are specified is unimportant except for the lowercase L and i options Options may be separated from arguments if they have them by an optional space The following summarize the linker options a CT e global symbol f fill value g global symbol h help 9 heap size i dir j k Produce an absolute executable module This is
431. th Figure 10 3 Data and Memory Widths Data after phase I of hex utility Data after phase Il of hex utility 10 4 4 ROM Width Source file word OAABBh word 01122h Data width 16 fixed OAABBh O12 Za Memory widths variable data width 16 memwidth 16 default memwidth 8 ROM width specifies the physical width in bits of each ROM device and corre sponding output file usually one byte or eight bits The ROM width deter mines how the hex conversion utility partitions the data into output files After the target words are mapped to the memory words the memory words are bro ken into one or more output files The number of output files per address range is determined by the following formula where memory width ROM width number of files memory width ROM width For example for a memory width of 16 you could specify a ROM width of 16 and get a single output file containing 16 bit words Or you can use a ROM width value of 8 to get two files each containing 8 bits of each word For more information on calculating the number of files per address range see Section 10 5 The ROMS Directive on page 10 16 Hex Conversion Utility Description 10 11 Understanding Memory Widths 10 12 The default ROM width that the hex conversion utility uses depends on the out put format All hex formats except Tl Tagged are configured as lists of 8 bit bytes the default ROM widt
432. ther bootorg PARALLEL nor bootorg SERIAL affect the address field 10 10 2 Controlling the Address Increment Index By default the hex conversion utility increments the output file address field according to the memory width value If memory width equals 16 the address increments on the basis of how many 16 bit words are present in each line of the output file 10 10 3 The byte Option Some EPROM programmers may require the output file address field to contain a byte count rather than a word count If you use the byte option the output file address increments once for each byte For example if the starting address is Oh the first line contains eight words and you use no byte option the second line would start at address 8 8h If the starting address is Oh the first line contains eight words and you use the byte option the second line would start at address 16 010h The data in both examples are the same byte affects only the calculation of the output file address field not the actual target processor address of the converted data The byte option causes the address records in an output file to refer to byte locations within the file whether the target processor is byte addressable or not 10 10 4 Dealing With Address Holes When memory width is different from data width the automatic multiplication ofthe load address by the correction factor might create holes at the beginning of a section or between sectio
433. ting file 1 000000 Space 29 2 copy byte asm A 1 In byte asm A 2 000002 0020 byte 32 14 A 000003 0042 A 3 copy word asm B i In word asm B 2 000004 ABCD word OABCDh 56q 000005 002E Back in byte asm 000006 006A byte 67h 3q Back in original file 000007 646F pstring done 000008 6E65 O10 0 Assembler Directives 4 37 copy include Read Source File Example 2 In this example the include directive is used to read and assemble source statements from other files then the assembler resumes assembling into the current file The mechanism is similar to the copy directive except that state ments are not printed in the listing file include asm byte2 asm word2 asm source file first include file second include file Space 29 In byte2 asm In word2 asm include byte2 asm byte 32 1 A include word2 asm Back in byte2 asm byte 67h 3q Back in original file String done Listing file 1 000000 Space 29 2 include byte2 asm 3 4 Back in original file 5 000007 0064 string done 000008 006F 000009 006E 00000a 0065 4 38 Syntax Description Example Assign Character Strings to Substitution Symbols data data The data directive tells the assembler to begin assembling source code into the data section data becomes the current section The data section is normally used to contain tables of data or preinitialized vari
434. ting unresolved symbol references You can use the archiver to build and maintain libraries Chapter 6 Archiver Description contains more information about the archiver Using object libraries can reduce link time and the size of the executable module Normally if an object file that contains a function is specified at link time it is linked whether it is used or not however if that same function is placed in an archive library it is included only if it is referenced The order in which libraries are specified is important because the linker includes only those members that resolve symbols that are undefined when the library is searched The same library can be specified as often as neces sary itis searched each time it is included Alternatively the x option can be used A library has a table that lists all external symbols defined in the library the linker searches through the table until it determines that it cannot use the library to resolve any more references The following examples link several files and libraries Assume that DD Input files f1 obj and f2 obj both reference an external function named clrscr Input file f1 0bj references the symbol origin Input file f2 0bj references the symbol fillclr Member 0 of library libc lib contains a definition of origin D D D Member 3 of library liba lib contains a definition of fillclr Member 1 of both libraries defines clrscr For example if you enter the followi
435. tion The d option equates a constant value with a symbol The symbol can then be used in place of a value in assembly source The format of the d option is as follows asm500 dname value The nameis the name of the symbol you want to define The value is the value you want to assign to the symbol If the value is omitted the symbol is set to 1 Within assembler source you may test the symbol with the following direc tives Type of Test Directive Usage Existence if Sisdefed name Nonexistence if Sisdefed name 0 Equal to value if name value Not equal to value if name value Note that the argument to the isdefed built in function must be enclosed in quotes The quotes cause the argument to be interpreted literally rather than as a substitution symbol 3 8 A Predefined Symbolic Constants The assembler has several predefined symbols including the following LJ the dollar sign character represents the current value of the section program counter SPC Lj Register symbols including ARO AR7 Memory mapped registers are set up as symbols by the assembler Symbols 3 8 5 Substitution Symbols Symbols can be assigned a string value variable This enables you to alias character strings by equating them to symbolic names Symbols that represent character strings are called substitution symbols When the assembler encounters a substitution symbol its string value is substituted fo
436. tion s Option The s option creates a smaller output module by omitting symbol table information and line number entries The s option is useful for production applications when you must create the smallest possible output module This example links file1 obj and file2 obj and creates an output module stripped of line numbers and symbol table information named nosym out 1nk500 o nosym out s filel obj file2 obj Using the s option limits later use of a symbolic debugger and may prevent a file from being relinked Linker Description 7 17 Linker Options 7 4 16 Define Stack Size stack constant Option The TMS320C54x C C compiler uses an uninitialized section stack to allocate space for the runtime stack You can set the size of the stack section at link time with the stack option Specify the size in words as a constant immediately after the option 1nk500 stack 0x1000 defines a stack size If you specified a different stack size in an input section the input section stack size is ignored Any symbols defined in the input section remain valid only the stack size will be different When the linker defines the stack section it also defines a global symbol __STACK_SIZE and assigns it a value equal to the size of the section The default stack size is 1K words 7 4 17 Introduce an Unresolved Symbol u symbol Option The u option introduces an unresolved symbol into the linker s symbol table This
437. tion Insure that there are no other labels that could be identical to a generated macro local label Mnemonic to Algebraic Translator Description 11 9 How the Translator Works With Macros 11 5 3 Defining Labels When Invoking A Macro If there is a label associated with a macro invocation that label is not used after expansion and translation This is because the label is commented out with the macro invocation Thefollowing source code preprocesses to the intermediate code as shown Figure 11 4 Defining Labels a Source code mymac macro word F403 endm LABEL mymac b Intermediate code mymac macro word F403 endm LABEL mymac word F403 LABEL is not defined when the code is assembled Insure that label definitions do not appear on the same line as the macro invocations Rewrite the source code in the example above as follows Figure 11 5 Rewritten Source Code mymac macro word F403 endm LABEL mymac 11 10 Appendix A Common Object File Format The compiler assembler and linker create object files in common object file format COFF COFF is an implementation of an object file format of the same name that was developed by AT amp T for use on UNIX based systems This for mat is used because it encourages modular programming and provides more powerful and flexible methods for managing code segments and target system memory Sections are a basic CO
438. tion The symbol used with the e option is not defined errors in input not built Description Previous errors prevent the creation of an output file fail to copy Description The file may be corrupt Action If the input file is corrupt try reassembling it fail to read Description The file may be corrupt Action If the input file is corrupt try reassembling it fail to seek Description The file may be corrupt Action If the input file is corrupt try reassembling it Linker Error Messages fail to skip Description The file may be corrupt Action If the input file is corrupt try reassembling it fail to write Description The disk may be full or protected Action Check disk volume and protection file has no relocation information Description You have attempted to relink a file that was not linked with r file is of unknown type magic number Description The binary input file is not a COFF file fill value for redefined Description More than one fill value is supplied for an output section Indi vidual holes can be filled with different values with the section definition i path too long Description The maximum number of characters in an i path is 256 illegal input character Description There is a control character or other unrecognized character in the command file illegal memory attributes for Descriptio
439. tion again The assembler continues doing this until it encounters a token that is not a substitution symbol or until it encounters a substitution symbol that it has already encountered during this evaluation In Example 5 6 the x is substituted for z z is substituted for y and y is substituted for x The assembler recognizes this as infinite recursion and ceases substitution asg asg asg add Wee x Z gtk y yt x X X A A declare z and assign z declare y and assign y declare x and assign x recursive expansion Hs wow HA Macro Parameters Substitution Symbols 5 3 4 Forced Substitution In some cases substitution symbols are not recognizable to the assembler The forced substitution operator which is a set of colons enables you to force the substitution of a symbol s character string Simply enclose a symbol in colons to force the substitution Do not include any spaces between the colons and the symbol The syntax for the forced substitution operator is symbol The assembler expands substitution symbols enclosed in colons before it expands other substitution symbols You can use the forced substitution operator only inside macros and you cannot nest a forced substitution operator within another forced substitution operator Example 5 7 shows how the forced substitution operator is used Example 5 7 Using the Forced Substitution Operator f
440. tion displays additional messages pertaining to the creation of memory sections Additional messages are displayed in the following circumstances In a linker command file you can set up a SECTIONS directive that describes how input sections are combined into output sections However ifthe linker encounters one or more input sections that do not have a corre sponding output section defined in the SECTIONS directive the linker combines the input sections that have the same name into an output section with that name By default the linker does not display a message to tell you when this has occurred If this situation occurs and you use the w option the linker displays a message when it creates a new output section If you do not use the heap and stack options the linker creates the sysmem and stack respectively sections for you Each section has a default size of 0x400 words You might not have enough memory available for one or both of these sections In this case the linker issues an error message saying a section could not be allocated If you use the w option the linker displays another message with more details which includes the name of the directive to allocate the sysmem or stack section yourself For more information about the SECTIONS directive see Section 7 8 The SECTIONS Directive on page 7 32 For more information about the default actions of the linker see Section 7 12 Default Allocation Algorit
441. tive assigns symbolic offsets to the elements of alternate data structure definitions to be allocated in the same memory space This enables you to define several alternate structures and then let the assembler calculate the element offset This is similar to a C union The union directive does not allocate any memory it merely creates a symbolic template that can be used repeatedly A struct definition may contain a union definition and structs and unions may be nested The endunion directive terminates the union definition The tag directive gives structure or union characteristics to a abel simplifying the symbolic representation and providing the ability to define structures or unions that contain other structures or unions The tag directive does not allo cate memory The structure or union tag of a tag directive must have been pre viously defined utag expr memp element eXptm size Declare Union Type union endunion tag is the union s tag Its value is associated with the beginning of the union If no utag is present the assembler puts the union members in the global symbol table with the value of their abso lute offset from the top of the union In this case each member must have a unique name is an optional expression indicating the beginning offset of the union Unions default to start at 0 This parameter can only be used with a top level union It cannot be used when defining a nested union
442. tives define a member s size they do not initialize memory For more information about struct endstruct see Section 4 9 Assembly Time Symbol Directives on page 4 21 Example This example shows the double and Idouble directives 1 000000 E904 double 1 0e25 000001 5951 2 000002 43E4 ldouble 456 0 000003 0000 Syntax Description Example Controls Listing of Directives drlist drnolist drlist drnolist Two directives enable you to control the printing of assembler directives to the listing file The drlist directive enables the printing of all directives to the listing file The drnolist directive suppresses the printing of the following directives to the listing file asg Lj break emsg Lj eval DD fclist DL D O O LI fcnolist mlist mmsg mnolist SSlist D ssnolist var Lj wmsg By default the assembler acts as if the drlist directive had been specified This example shows how drnolistinhibits the listing of the specified directives Source file asg 0 x loop 2 eval xt t1 x endloop drnolist asg l x loop 3 eval xtl x endloop Listing file 1 asg 0 x 2 loop 2 3 eval xl x 4 endloop I eval O 1 x I eval Lady X 5 6 drnolist 7 9 loop 3 10 eval xtl x 11 endloop Assembler Directives 4 41 emsg mmsg wmsg Define Messages Syntax Description Example emsg string mmsg string wmsg string These directi
443. tput section the linker must supply raw data to fill it The linker fills holes with a 16 bit fill value that is replicated through memory until it fills the hole The linker determines the fill value as follows 1 Ifthe hole is formed by combining an uninitialized section with aninitialized section you can specify a fill value for the uninitialized section Follow the section name with an sign and a 16 bit constant SECTIONS outsect filel obj text file2 obj bss OOFFh Fill this hole with OFFh 2 You can also specify a fill value for all the holes in an output section by supplying the fill value after the section definition SECTIONS outsect fill OFFOOh fills holes with OFFOOh 10h This creates a hole filel obj text filel obj bss This creates another hole Creating and Filling Holes 3 If you do not specify an initialization value for a hole the linker fills the hole with the value specified by the f option For example suppose the command file link cmd contains the following SECTIONS directive SECTIONS text 100 Create a 100 word hole Now invoke the linker with the f option lnk500 f OFFFFh link cmd This fills the hole with OFFFFh 4 If you do not invoke the linker with the f option the linker fills holes with Os Whenever a hole is created and filled in an initialized output section the hole is id
444. tring of decimal digits You can precede nnn with a or a You must specify a decimal point For example 3 e5 is valid but 3e5 is not valid The exponent indicates a power of 10 These are examples of valid constants 3 0 3 14 3 0 314e13 314 59e 2 Assembler Description 3 17 Character Strings 3 7 Character Strings 3 18 A character string is a string of characters enclosed in double quotes Double quotes that are part of character strings are represented by two consecutive double quotes The maximum length of a string varies and is defined for each directive that requires a character string Characters are represented internally as 8 bit ASCII characters These are examples of valid character strings sample program defines the 14 character string sample program PLAN C defines the 8 character string PLAN C Character strings are used for the following Filenames as in copy filename Section names as in sect section name Data initialization directives as in byte charstring Operands of string directives O O O L 3 8 Symbols 3 8 1 Labels Symbols Symbols are used as labels constants and substitution symbols A symbol name is a string of up to 200 alphanumeric characters A Z a z 0 9 and The first character in a symbol cannot be a number and symbols can not contain embedded blanks The symbols you define are case sensitive for example the assembler
445. trol conditional assembly Mnemonic and Syntax Description Page break well defined expression End loop assembly if condition is true The break 4 66 construct is optional else Assemble code block if the if condition is false The 4 56 else construct is optional This directive can be used as the default case in a conditional block elseif well defined expression Assemble code block if the if condition isfalse andthe 4 56 elseif condition is true The elseif construct is optional endif End if code block 4 56 endloop End loop code block Af well defined expression Assemble code block if the condition is true 4 56 loop well defined expression Begin repeatable assembly of a code block The well 4 66 defined expression is a loop count Assembler Directives 4 5 Directives Summary Table 4 1 Assembler Directives Summary Continued h Directives that define symbols at assembly time Mnemonic and Syntax asg character string substitution symbol endstruct endunion equ eval well defined expression substitution symbol label symbol Set Struct tag union 4 6 Description Assign a character string to a substitution symbol End structure definition End union definition Equate a value with a symbol Perform arithmetic on numeric substitution symbols Define a load time relocatable label in a section Equate a value with a symbol Begin structure definition Assign
446. u have included a list of files files on that range the utility takes the filename from the list For example assume that the target data is 16 bit words being converted totwo files each eight bits wide To name the output files using the ROMS directive you could specify ROMS RANGE1 romwidth 8 files xyz b0 xyz bl The utility creates the output files by writing the least significant bits LSBs to xyz b0 and the most significant bits MSBs to xyz b1 It looks for the o options You can specify names for the output files by using the o option If no filenames are listed in the ROMS directive and you use o options the utility takes the filename from the list of o options The following line has the same effect as the example above using the ROMS directive o xyz b0 o xyz bl Note that if both the ROMS directive and o options are used together the ROMS directive overrides the o options 3 Ouiput Filenames It assigns a default filename If you specify no filenames or fewer names than output files the utility assigns a default filename A default filename consists of the base name from the COFF input file plus a 2 to 3 character extension e g filename abc The extension has three parts a Aformat character based on the output format a for ASCII Hex i for Intel t for Tl Tagged m for Motorola S x for Tektronix b The range number in the ROMS directive Ranges are number
447. ue 7 14 1 Syntax of Assignment Statements The syntax of assignment statements in the linker is similar to that of assign ment statements in the C language symbol expression assigns the value of expression to symbol symbol expression adds the value of expression to symbol symbol expression subtracts the value of expression from symbol symbol expression multiplies symbol by expression symbol expression divides symbol by expression The symbol should be defined externally If it is not the linker defines a new symbol and enters it into the symbol table The expression must follow the rules defined in subsection 7 14 3 Assignment Expressions Assignment statements must terminate with a semicolon The linker processes assignment statements after it allocates all the output sections Therefore if an expression contains a symbol the address used for that symbol reflects the symbol s address in the executable output file For example suppose a program reads data from one of two tables identified by two external symbols Table1 and Table2 The program uses the symbol cur tab as the address of the current table cur tab must point to either Table1 or Table2 You could accomplish this in the assembly code but you would need to reassemble the program to change tables Instead you can use a linker assignment statement to assign cur tab at link time prog obj Input file f cur tab Tablel Assign cur tab to one
448. ue label generation in a macro Example 5 13 Unique Labels in a Macro a Mnemonic example 1 define macro 2 MIN macro AVAR BVAR find minimum 3 4 LD AVAR A 5 SUB BVAR A 6 BC M1 ALT ri LD BVAR A 8 B M2 9 M1 LD AVAR A 10 M2 d endm 12 13 call macro 14 000000 MIN 50 100 000000 1032 LD 50 A 000001 F010 SUB 100 A 000002 0064 000003 F843 BC M1 ALT 000004 0008 000005 E864 LD 100 A 000006 F073 B M2 000007 0009 000008 1032 M1 LD 50 A 000009 M2 Macro Language 5 17 Using Labels in Macros Example 5 13 Unique Labels in a Macro Continued b Algebraic example T define macro 2 MIN macro AVAR BVAR find minimum 3 4 A AVAR 5 A A BVAR 6 if ALT goto M1 7 A BVAR 8 goto M2 9 M1 A AVAR 10 M2 11 endm 12 13 call macro 14 000000 MIN 50 100 000000 1032 A 50 000001 F010 A A 100 000002 0064 000003 F843 if ALT goto M1 000004 0008 000005 E864 A 100 000006 F073 goto M2 000007 0009 000008 1032 M1 A 50 000009 M2 5 18 Producing Messages in Macros 5 7 Producing Messages in Macros The macro language supports three directives that enable you to define your own assembly time error and warning messages These directives are especially useful when you want to create messages specific to your needs The last line of the listing file shows the error and warn
449. ult P 14 described to 7 ed map defined described model 7 27 named pool C language unconfigured widths described td 10 1 ordering memory wor 10 14 to 10 15 to 10 13 ROM width target width word ordering PAGE option memory ranges allocation to multiple defined 7 27 MEMORY directive messages assembler Eep linker E 1 to E 16 mexit directive 5 3 mf assembler option mg assembler option mlib directive use in macros mlist directive SEV SI listing control use in macros mmregs directive Index 10 to syntax to mmsg directive listing control mnem2alg command mnemonic defined field translation to algebraic 11 1 to 11 10 mnemonic to algebraic translator utility See transla tor mnolist directive listing control 4 17 4 41 use in macros model statement defined F 5 Motorola S object format 10 42 name MEMORY specification 7 29 named sections COFF format defined sect directive 2 8 usect directive nested macros newblock directive no remark directive nolist directive same effect with option directive 4 17 NOLOAD section noremark directive 4 75 o linker option 7 17 object code source listing formats adaress bits ASCII Hex Intel Motorola S output width Tektronix Tl Tagged library altering search algorithm defined F 6 described to object library continued runtime su
450. upport e Library of e library e object 1 5 files Linker ll Debugging 4 tools Executable EL COFF file Hex conversion utility EPROM programmer 10 2 Invoking the Hex Conversion Utility 10 2 Invoking the Hex Conversion Utility There are two basic methods for invoking the hex conversion utility Specify the options and filenames on the command line The following example converts the file firmware out into Tl Tagged format producing two output files firm lsb and firm msb hex500 t firmware o firm lsb o firm msb Specify the options and filenames in a command file You can create a batch file that stores command line options and filenames for invoking the hex conversion utility The following example invokes the utility using a command file called hexutil cmd hex500 hexutil cmd In addition to regular command line information you can use the hex conversion utility ROMS and SECTIONS directives in a command file To invoke the hex conversion utility enter hex500 options filename hex500 is the command that invokes the hex conversion utility options supplies additional information that controls the hex conversion process You can use options on the command line or in a com mand file DD All options are preceded by a dash and are not case sensi tive Several options have an additional parameter that must be separated from the o
451. ust have at least one value parameter but you have the option of supplying additional value parameters separated by commas Following are other symbols and abbreviations used throughout this document Symbol Definition Symbol Definition ARO AR7 Auxiliary Registers PC Program counter 0 through 7 register B b Suffix binary integer Q q Suffix octal integer H h Suffix hexadecimal SP Stack pointer register integer LSB Least significant bit ST Status register MSB Most significant bit C54x is used throughout this manual to collectively refer to all supported C54x devices Read This First V Helated Documentation From Texas Instruments Trademarks Related Documentation From Texas Instruments Trademarks vi The following books describe the TMS320C54x devices and related support tools To obtain a copy of any of these TI documents call the Texas Instruments Literature Response Center at 800 477 8924 When ordering please identify the book by its title and literature number TMS320C54x Optimizing C Compiler User s Guide literature number SPRU103 describes the TMS320C54x C compiler This C compiler accepts ANSI standard C source code and produces assembly language source code for the TMS320C54x generation of devices TMS320C54x DSP Reference Set Volume 1 CPU literature number SPRU131 describes the TMS320C54x 16 bit fixed point general purpose digital signal processors Covered are its architectu
452. utes a particular task several times The macro language lets you DD Define your own macros and redefine existing macros L Simplify long or complicated assembly code Access macro libraries created with the archiver D Define conditional and repeatable blocks within a macro DD Manipulate strings within a macro J Control expansion listing Topic Page SslaU SingINacto Ss ee E 5 2 5 2ugDetiningiMacrosq a 5 3 5 3 Macro Parameters Substitution Symbols 5 4 Macro Libraries I II eI rIEEeT sers 5 5 Using Conditional Assembly in Macros eese 5 15 5 5uUsingilabelsiiniMacros me 5 17 5 7 Producing Messages in Macros ee 5 8 Formatting the Output Listing eese 5 21 5 9 Using Recursive and Nested Macros eene 5 22 5 10 Macro Directives Summary pp 5 25 Using Macros 5 1 Using Macros Programs often contain routines that are executed several times Instead of repeating the source statements for a routine you can define the routine as a macro then call the macro in the places where you would normally repeat the routine This simplifies and shortens your source program If you wantto call a macro several times but with different data each time you can assign parameters within a macro This enables you to pass different information to the macro each time you call it The macro language supports a special symbol called a substitution symbol which
453. val The set and equ directives produce no object code The two directives are identical and can be used interchangeably The struct endstruct directives set up C like structure definitions and the tag directive assigns the C like structure characteristics to a label The struct endstruct directives allow you to organize your information into structures so that similar elements can be grouped together Element offset calculation is then left up to the assembler The struct endstruct directives do not allocate memory They simply create a symbolic template that can be used repeatedly Assembler Directives 4 21 Assembly Time Symbol Directives 4 22 The tag directive associates structure characteristics with a label symbol This simplifies the symbolic representation and also provides the ability to define structures that contain other structures The tag directive does not allocate memory and the structure tag stag must be defined before it is used type struct Structure tag definition X dnt Y int T LEN endstruct COORD tag type declare COORD coordinate ADD COORD Y A bss COORD T LEN actual memory allocation The union endunion directives create a symbolic template that can be used repeatedly providing a way to manipulate several different kinds of data in the same storage area The union sets up a C like union definition While itdoes notallocate any memory it allows alternate definitions
454. value they would have if the DSECT had actually been loaded These sym bols can be referenced by other input sections m Undefined external symbols found in a DSECT cause specified archive libraries to be searched B The section s contents relocation information and line number information are not placed in the output module In the preceding example none of the sections from f1 0bj are allocated but all of the symbols are relocated as though the sections were linked at word address 2000h The other sections can refer to any of the global symbols in sec1 A COPY section is similar to a DSECT section except that its contents and associated information are written to the output module The cinit section that contains initialization tables for the TMS320C54x C compiler has this attribute under the RAM model The comment section created by pragma IDENT is a COPY section A NOLOAD section differs from a normal output section in one respect the section s contents relocation information and line number informa tion are not placed in the output module The linker allocates space for it and it appears in the memory map listing Linker Description 7 61 Assigning Symbols at Link Time 7 14 Assigning Symbols at Link Time Linker assignment statements allow you to define external global symbols and assign values to them at link time You can use this feature to initialize a variable or pointer to an allocation dependent val
455. ve assigns a character string to a substitution symbol The syntax of the asg directive is asg character string substitution symbol The quotation marks are optional If there are no quotation marks the assembler reads characters up to the first comma and removes leading and trailing blanks In either case a character string is read and assigned to the substitution symbol Example 5 3 shows character strings being assigned to substitution symbols Macro Language 5 7 Macro Parameters Substitution Symbols Example 5 3 The asg Directive asg ARO FP asg AR1 Ind asg AR1 0b Rc_Prop asg string strng asg a b c parms frame pointer indirect addressing reverse carry propagation string parameters m Ne The eval directive performs arithmetic on numeric substitution symbols The syntax of the eval directive is eval well defined expression substitution symbol The eval directive evaluates the expression and assigns the string value of the result to the substitution symbol If the expression is not well defined the assembler generates an error and assigns the null string to the symbol Example 5 4 shows arithmetic being performed on substitution symbols Example 5 4 The eval Directive asg 1 counter loop 100 word counter eval counter 1 counter endloop In Example 5 4 the asg directive could be replaced with the eval d
456. ves allow you to define your own error and warning messages The assembler tracks the number of errors and warnings it encounters and prints these numbers on the last line of the listing file The emsg directive sends error messages to the standard output device in the same manner as the assembler incrementing the error count and prevent ing the assembler from producing an object file The mmsg directive sends assembly time messages to the standard output device in the same manner as the emsg and wmsg directives but it does not set the error or warning counts and it does not prevent the assembler from producing an object file The wmsg directive sends warning messages to the standard output device inthe same manner as the emsg directive but it increments the warning count rather than the error count and it does not prevent the assembler from produc ing an object file In this example the message ERROR MISSING PARAMETER is sent to the standard output device Source file global PARAM MSG EX macro parml dif symlen parml 0 emsg ERROR MISSING PARAMETER else add parml A endif endm MSG EX PARAM MSG EX Define Messages emsg mmsg wmsg Listing file 1 global PARAM 2 MSG EX macro parml 3 sd Ssymlen parml 0 4 emsg ERROR MISSING PARAMETER 5 else 6 add parml A 7 endif 8 endm 9 10 000000 MSG EX PARAM 1 AE Ssymlen parml 0 1 emsg ER
457. vice Assembler Directives 4 7 Compatibility With the TMS320C1x C2x C2xx C5x Assembler Directives 4 2 Compatibility With the TMS320C1x C2x C2xx C5x Assembler Directives 4 8 This section explains how the TMS320C54x assembler directives differ from the TMS320C1x C2x C2xx C5x assembler directives L The C54x long and float directives place the most significant word of the value at the lower address while the C1x C2x C2xx C5x assembler direc tives place the east significant word at the lower address Also the C54x long and float directives automatically align the SPC on an even word boundary while the C1x C2x C2xx C5x assembler directives do not Without arguments the C54x and the C1x C2x C2xx C5x assemblers both align the SPC at the next 128 word boundary However the C54x align directive also accepts a constant argument which must be a power of 2 and this argument causes alignment of the SPC on that word bound ary The align directive for the C1x C2x C2xx C5x assembler does not accept this constant argument The field directive forthe C54x packs fields into words starting at the most significant bit of the word The C1x C2x C2xx C5x assembler field direc tive places fields into words starting at the east significant bit of the word The field directive for the C54x handles values of 1 to 32 bits contrasted with the C1x C2x C2xx C5x assembler which handles values of 1 to 16 bits With the C54x assembler
458. word x word 2 eval x 1 x eval 2 1 x 000005 0003 word x word 3 eval x 1 x eval 341 x 000006 0004 word x word 4 eval x 1 x eval 4 1 x 000007 0005 word x word 5 Assembler Directives 4 29 DSS Reserve Space in the bss Section Syntax Description bss symbol size in words blocking flag alignment flag The bss directive reserves space for variables in the bss section This directive is typically used to allocate variables in RAM m d The symbolis a required parameter It defines a label that points to the first location reserved by the directive The symbol name corresponds to the variable that you re reserving space for The size is a required parameter it must be an absolute expression The assembler allocates size words in the bss section There is no default size The blocking flag is an optional parameter If you specify a non zero value for this parameter the assembler allocates size words contiguously This means that the allocated space will not cross a page boundary unless size is greater than a page in which case the object will start on a page bound ary The alignment flag is an optional parameter This flag causes the assembler to allocate size on long word boundaries Note Specifying an Alignment Flag Only To specify an alignment flag without a blocking flag you can insert two commas before the alignment flag or you can specify
459. xpansion Mode e Option Expansion mode is invoked using the e option In expansion mode the translator preprocesses macros and substitution symbols and then translates instructions The translator invokes the assembler with a switch that prepro cesses the input to expand macros and insert substitution symbols The assembler creates a file with an exp extension The expfile is passed back to the translator for processing The translator creates a file with the same name as the assembler source file and an extension of cnv Since the translator invokes the assembler in expansion mode you must include the assembler executable in your path The assembler executable version must be 1 11 or above If the assembler encounters errors during pre processing the translator aborts and no output is produced Figure 11 3 Expansion Mode Process 11 6 Command menme2alg e filename asm Assembly with switch Intermediate file filename exp Translation Translator Converted file filename cnv The following example demonstrates how expansion mode works In the intermediate file the macro invocation is commented out and the expanded macro is inserted in its place with the actual arguments substituted in Although the macro definition was not translated the resulting cnvfile can be assembled by the algebraic assembler to produce output The assembler does not process macro definitions for the same reasons the translator does not trans
460. y Time Symbol Directives eeeeeee 4 10 Miscellaneous Directives 0 ccece eee eceee ee ceeeeees 4 11 Directives Reference er PPP MM MM 4 1 Directives Summary 4 1 Directives Summary This section summarizes the assembler directives Assembler directives and their parameters must be specified entirely on one line Besides the assembler directives documented here the TMS320C54x software tools support the following directives The assembler uses several directives for macros The macro directives are listed in this chapter but they are described in detail in Chapter 5 Macro Language The absolute lister also uses directives Absolute listing directives are not entered by the user but are inserted into the source program by the absolute lister Chapter 8 Absolute Lister Description discusses these directives they are not discussed in this chapter The C C compiler uses directives for symbolic debugging Unlike other directives symbolic debugging directives are not used in most assembly language programs Appendix B Symbolic Debugging Directives discusses these directives they are not discussed in this chapter Note Labels and Comments in Syntax In most cases a source statement that contains a directive may also contain a label and a comment Labels begin in the first column they are the only elements except comments that can appear in the first column and com me
461. y bridges these gaps by using the address records in the output file to skip ahead to the start of the next section In other words there may be discontinuities in the output file addresses Some EPROM programmers do not support address disconti nuities In image mode there are no discontinuities Each output file contains a contin uous stream of data that corresponds exactly to an address range in target memory Any gaps before between or after sections are filled with a fill value that you supply An output file converted by using image mode still has address records because many of the hexadecimal formats require an address on each line However in image mode these addresses will always be contiguous M LU SSCCSN GJ Note Defining the Ranges of Target Memory If you use image mode you mustalso use a ROMS directive In image mode each output file corresponds directly to a range of target memory You must define the ranges If you don t supply the ranges of target memory the utility tries to build a memory image of the entire target processor address space potentially a huge amount of output data To prevent this situation the utility requires you to explicitly restrict the address space with the ROMS directive Image Mode and the fill Option 10 8 2 Specifying a Fill Value The fill option specifies a v
462. y member has no relocation information It is possible for a library member to not have relocation informa tion this means that it cannot satisfy unresolved references in other files when linking line number entry found for absolute symbol Description The input file may be corrupt Action If the input file is corrupt try reassembling it load address for uninitialized section ignored Description A load address is supplied for an uninitialized section Unini tialized sections have no load addresses only run address es load address for UNION ignored Description UNION refers only to the section s run address load allocation required for initialized UNION member Description Aload address is supplied for an initialized section in a union UNIONS refer to runtime allocation only You must specify the load address for all sections within a union separately m flag does not specify a valid filename Description You did not specify a valid filename for the file you are writing the output map file to making aux entry filename for symbol n out of sequence Description The input file may be corrupt Action If the input file is corrupt try reassembling it Linker Error Messages E 9 Linker Error Messages E 10 memory area for redefined Description More than one named memory allocation is supplied for an output section memory page for redefined Description More than one page allocation is supp
463. ymbols i 5 3 2 Built In Substitution Symbol Functions i 5 3 8 Recursive Substitution Symbols i 5 3 4 Forced Substitution i 5 3 5 Accessing Individual Characters of Subscripted Substitution Symbols 5 3 6 Substitution Symbols as Local Variables in Macros ae 5 5 Using Conditional Assembly in Macros i 5 6 Using Labels in Macros riei i teen eens 5 7 Producing Messages in Macros arene 5 8 Formatting the Output Listing 00 c cece tenes 5 9 Using Recursive and Nested Macros i 5 10 Macro Directives Summary sa a i eens Archiver Description 00 sce eee e eee eee eee I Rh hh mnn Contains instructions for invoking the archiver creating new archive libraries and modifying existing libraries 6 14 Archiver Overview si dr a eet eee eee 6 2 Archiver Development Flow 6 3 Invoking the Archiver 0000 a n 6 4 Archiver Examples sis Linker Description 0c cee eee eee III HH HH nr 7 1 Explains how to invoke the linker provides details about linker operation discusses linker directives and presents a detailed linking example YS Linker Overview so ne pete ol esf n st RR grade se iis ete biden 7 2 Linker Development Flow 7 3 Invoking the Linker 000 e eni hn 3 4 Linker Options ssa ENERO RES ERE oap RE D RED NAR REED 7 4 4 Relocation Capabilities Ca and r Options eee eee 7 4 2 Disable Merge of Symbolic Debugging Information
464. yntax is not present Action Correct the source per the error message text Assembler Error Messages Invalid mnemonic specification Description This error relates to invalid mnemonics The instruction macro or directive specified was not recognized Action Check the directive or instruction used Invalid instruction for specified processor version Description The indicated instruction is not allowed for the processor ver sion specified with the version directive Action Check the instruction and version directive Cluttered character operand encountered Cluttered identifier operand encountered Cluttered register operand encountered Cluttered string constant operand encountered Conditionals cannot begin in the first column Condition must be EQ LT GT or NEQ Condition must be srcEQ NEG LT LEQ GT or GEQ Expecting ARn for src dst Expecting shift or accumulator Illegal auxiliary register specified Illegal condition operand Illegal condition operand or combination Illegal indirect memaddr specification Illegal operand Illegal smem operand Immediate value out of range Invalid binary constant specified Invalid constant specification Invalid decimal constant specified Invalid float constant specified Invalid hex constant specified Assembler Error Messages D 3 Assembler Error Messages D 4 Invalid immediate or shift value Invalid octal constant specified Invalid Operand 2 Invalid operand x Inva
465. you can build your own runtime libraries The assembler translates assembly language source files into machine language COFF object files Source files can contain instructions assem bler directives and macro directives You can use assembler directives to control various aspects of the assembly process such as the source list ing format data alignment and section content The linker combines relocatable COFF object files created by the assembler into a single executable COFF object module As it creates the executable module it binds symbols to memory locations and resolves all references to those symbols It also accepts archiver library members and output modules created by a previous linker run Linker directives allow you to combine object file sections bind sections or symbols to addresses or within memory ranges and define or redefine global symbols The archiver collects a group of files into a single archive file For example you can collect several macros into a macro library The assembler searches the library and uses the members that are called as macros by the source file You can also use the archiver to collect a group of object files into an object library The linker includes in the library the members that resolve external references during the link The mnemonic to algebraic assembly translator utility converts an assembly language source file containing mnemonic instructions to an assembly language source file con
466. ystem memory by defining and creating a memory model that you design Two powerful directives MEMORY and SECTIONS allow you to Allocate sections into specific areas of memory Combine object file sections Define or redefine global symbols at link time Linker Development Flow 7 2 Linker Development Flow Figure 7 1 illustrates the linker s role in the assembly language development process The linker accepts several types of files as input including object files command files libraries and partially linked files The linker creates an executable COFF object module that can be downloaded to one of several development tools or executed by a TMS320C54x device Figure 7 1 Linker Development Flow C Source files e Macro Source e files C compiler Macro library Translator utility Assembler source Assembler Assembler source Library build utility Runtime EC c z support e Libraryof library s object files 7 J Debugging tools Executable COFF file Hex conversion utility EPROM programmer Linker Description 7 3 Invoking the Linker 7 3 Invoking the Linker The general syntax for invoking the linker is Ink500 options filename filename Ink500 is the command that invokes the linker options can appear anywhere on the command

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