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Assembler/Linker/Librarian User's Guide

1. AA A A 5 DS33014J page 136 2005 Microchip Technology Inc Assembler Examples Tips and Tricks Lup movf Counter W get mask andwf Buffer W test selected bit btfss STATUS Z was result zero bsf Dat set data bsf Clk set clock bcf Clk clear clock bcf Dat clear data rrncf Counter F test next bit btfss Counter 7 done with byte bra Lup no bcf Bus indicate not busy return PRR RRR RRE AREA ke e ke ke ke he ke he ke e he ke ke ke he ke e he ke che ke ke che he ke e he kkk ke e he ke ke che ke ce he ke kkk kkk k k k global SPI Out Buffer end 2005 Microchip Technology Inc DS33014J page 137 Assembler Linker Librarian User s Guide 5 7 EXAMPLE OF HEXADECIMAL TO ASCII CONVERSION Directives highlighted in this example are udata res global 5 7 1 Program Functional Description This program converts a hexadecimal byte into two ASCII bytes The application is written as relocatable code i e you must use both the assembler and linker to generate the executable Program registers are assigned using the udata and res directives Sections of code are created using the code statement External code is accessed using global 5 7 2 Commented Code Listing PRR RRR check RRR KR he ke e ke ke Sk ce he ke he ke e he ke ke ke he ke e he ke ke ce ke ke e he ke e he A ke ce he k
2. m d sc s E 5 DS33014J page 152 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 7 Macro Language 7 1 INTRODUCTION Macros are user defined sets of instructions and directives that will be evaluated in line with the assembler source code whenever the macro is invoked Macros consist of sequences of assembler instructions and directives They can be written to accept arguments making them quite flexible Their advantages are Higher levels of abstraction improving readability and reliability Consistent solutions to frequently performed functions Simplified changes Improved testability Applications might include creating complex tables frequently used code and complex operations Topics covered in this chapter Macro Syntax Macro Directives Defined Macro Definition Macro Invocation Macro Code Examples 7 2 MACRO SYNTAX MPASM assembler macros are defined according to the following syntax label macro argl arg2 argn endm where label is a valid assembler label that will be the macro name and arg is any number of optional arguments supplied to the macro that will fit on the source line The values assigned to these arguments at the time the macro is invoked will be substituted wherever the argument name occurs in the body of the macro The body of a
3. DS33014J page 242 2005 Microchip Technology Inc pare Equivalent Mnemonic Description de Status Operation s ADDCF f d Add Carry to File BTFSC 3 0 Z INCF f d ADDDCF f d Add Digit Carry to File BTFSC 3 1 Z INCF f d B k Branch GOTO k BC k Branch on Carry BTFSC 3 0 GOTO k BDC k Branch on Digit Carry BTFSC 34 GOTO k BNC k Branch on No Carry BTFSS 3 0 GOTO k BNDC k Branch on No Digit Carry BTFSS 3 GOTO k BNZ k Branch on No Zero BTFSS 3 2 GOTO k BZ k Branch on Zero BTFSC 3 2 GOTO k CLRC Clear Carry BCF 3 0 CLRDC Clear Digit Carry BCF 3 1 CLRZ Clear Zero BCF 3 2 LCALL k Long Call BCF BSF 0x0A 3 BCF BSF 0x0A 4 CALL k LGOTO k Long GOTO BCF BSF 0x0A 3 BCF BSF 0x0A 4 GOTO k MOVEW Move File to W MOVF 0 NEGF f d Negate File COMF ft INCF f d SETC Set Carry BSF 3 0 SETDC Set Digit Carry BSF 3 1 SETZ Set Zero BSF 842 SKPC Skip on Carry BTFSS 3 0 SKPDC Skip on Digit Carry BTFSS 3 1 SKPNC Skip on No Carry BTFSC 3 0 SKPNDC Skip on No Digit Carry BTFSC 3 1 SKPNZ Skip on Non Zero BTFSC 3 2 SKPZ Skip on Zero BTFSS 3 2 SUBCF f d Subtract Carry from File BTFSC 3 0 Z DECF f d Instruction Sets TABLE A 7 12 BIT 14 BIT SPECIAL INSTRUCTION MNEMONICS CONTINUED 3 ae Equivalent Mnemonic Description Operation s Status SUBDCF f d Subtract Digit Carry f
4. S A A DS33014J page 108 2005 Microchip Technology Inc Directives STATUS register carry bit C may be affected movwf perimeter Move w to the perimeter low byte at address 20H Carry bit is unaffected rlf perimeter 1 Increment register 21H if carry was generated Also clear carry 1f bit was set rlf perimeter Multiply register 20H by 2 Carry bit may be affected rlf perimeter 1 Again increment register 21H 1f carry was generated The previous two lines of code will multiply by left shifting one bit the intermediate result by 2 goto Go to current line loop here end 4 57 set DEFINE AN ASSEMBLER VARIABLE 4 57 1 Syntax Preferred label set expr Supported label set expr 4 57 2 Description label is assigned the value of the valid MPASM assembler expression specified by expr The set directive is functionally equivalent to the equ directive except that set values may be subsequently altered by other set directives 4 57 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation Because set directive values may be altered by later set directives set is particularly useful when defining a variable in a loop e g a while loop 4 57 4 See Also equ variable while 4 57 5 Simple Example area set 0 width set 0x12 length se
5. A 3 12 BIT INSTRUCTION WIDTH INSTRUCTION SET Microchip s baseline 8 bit microcontroller family uses a 12 bit wide instruction set All instructions execute in a single instruction cycle unless otherwise noted Any unused opcode is executed as a NOP The instruction set is grouped into the following categories byte oriented file register operations bit oriented file register operations and core literal and control operations Additionally instructions that apply to both 12 bit and 14 bit devices are shown in Section A 5 12 Bit 14 Bit Instruction Width Pseudo Instructions Instruction opcode is show in hex by making certain assumptions either listed in the key or as a footnote For more information on the opcode bit values for each instruction as well as the number of cycles per instruction Status bits affected and complete instruction details see the relevant device data sheet TABLE A 1 12 BIT BYTE ORIENTED FILE REGISTER OPERATIONS Hex Mnemonic Description Function 1Ef ADDWF f d Add W and f WREG f gt dest 16f ANDWF f d AND W andf WREG AND f gt dest 06f CLRF E Clear f 0f 040 CLRW Clear W 0 5 WREG 26f COMF f d Complement f NOT f dest OEf DECF f d Decrement f f 1 dest 2Ef DECFSZ f d Decrement f skip if zero f 1 gt dest skip if zero 2Af INCF E d Increment f f 1 gt dest 3Ef INCFSZ f d Increment f skip if zero f 1 gt dest skip if zero 12f IORWF f d Inclusive OR W and f W
6. 99 ele RE E EROR IS 101 102 pagesel ede era etae 104 125 radix ien iei eiii tte 107 POS sect A eetees 108 125 136 138 SOL irc eaae eee iia 109 132 UO ata yes uoce tette reins 112 125 136 138 AAA deg me 113 data OVT de Oe at Sheen 115 Udala ES ER ER ellie 116 vatiable 5 ceci ttt 119 132 While a poc it 120 Examples Simple zdetlnes reana 69 A u 93 z tndeflne ere 118 bad AM ste AE Ne eise Mere 49 padrones Lt eie o Re Re o eius 50 CONT 2 5 conde de pet ep eedtelitos 59 EE 87 MAX AMEL eer ida 49 A ene ay eerste tects 50 bankisel eee ii 50 A bI 52 CDIOGCIK C S mtd esteem ner re er Mo 55 GOGUQS An E cess ten eL tra T 56 code pack sis eedem ates 57 COTITIQ i eite ar M HER US Pdf nt 60 datam cee eRe oes the Met 63 pp 65 OG 67 m nette les pere terre nr er aia 70 Was 71 CISC ER Re 71 eM CHE 72 eri Qmm 2 museum M M rer 738 equis used eO 74 GITOF ee epe EEE TE c ipee 75 errorlevel 221m bentes 76 AM eto eed e M ao ees nien MT 78 GXIGITz ii etia O Nm 80 Till siio oett oe pore dite 82 global m ee eene ege 84 NO ALA c csset cu Een ih cocci ca ad d er Pd 85 87 Veios enu auci ie 89 A bbDgU Ia Re 90 Dor a 91 IST AS tA ate eni ms ok 94 cai o EM 94 o E 96 MOSS ici eer OR ieee E xr EE 99 OL Re c aet PERRET TE EE RORIS 101 pagesel sssrrrrmiemmnmnihnannuns 104 105 PIOCESSOF s vies
7. N N N E p pi pd 4 4 N tion Registers in Banks 0 3 E sfro START 0x0 E sfrl START 0x80 E sfr2 START 0x100 E sfr3 START 0x180 ose RAM in Banks 0 3 E gprO START 0x20 E gpri START 0xA0 E gpr2 START 0x110 E gpr3 START 0x190 D 0x1F D 0x9F D 0x10F D 0x18F D 0x6F D 0xEF D 0x16F dada pd Z N D 0x1EF PRO PROT ECTE ECTEI PRO ECTE OC PRO ECTE RAM Memory Declarations for PIC16F877A Unbanked Memory General Purpose RAM available in all banks E gprnobnk S AR 0x70 E gprnobnk STAR 0xF0 0x170 11 5 2 E gprnobnk STAR E gprnobnk STAR 0x1F0 EN EN EN D 0x7F D OxFF D 0x17F EN D 0x1FF Defining ROM Memory Regions The CODEPAGE directive is used for program code initialized data values constant data values and external memory It has the following format CODEPAGE NAMI where E memName START addr END addr PROTECTED memName is any ASCII string used to identify a CODEPAGE FILL fillvalue DS33014J page 184 2005 Microchip Technology Inc Linker Scripts addr is a decimal or hexadecimal number specifying an address fillValueis a value which fills any unused portion of a memory block If this value is in decimal notation it is assumed to be a 16 bit quantity If it is in hexadecimal notation e g 0x2346 it may b
8. define RM RESET VECTOR 0x000800 define relocated vector addresses define RM HIGH INTERRUPT VECTOR 0x000808 define RM LOW INTERRUPT VECTOR 0x000818 VECTOR MAPPING KR KR RR RR RK RRR RR RK k k RR RK k k KK k k k pragma code HIGH INTERRUPT VECTOR 0x000008 void high ISR void _asm goto RM HIGH INTERRUPT VECTOR endasm 2005 Microchip Technology Inc DS33014J page 199 Assembler Linker Librarian User s Guide pragma code LOW INTERRUPT VECTOR 0x000018 void low ISR void BOOT LOADER CODE ESA _asm goto RM_LOW_INTERRUPT_VECTOR _endasm Hpragma code void main void Check Bootload Mode Entry Condition if PORTBbits RB4 1 If not pressed User Mode Else continue with bootloader code here _asm goto RM RESET VECTOR endasm pragma code user RM RESET VECTOR This address defined as 0x800 above or can be defined in header file END OF BOOT LOADER NA 13 5 5 MPLAB C18 Application Linker Script The partial MPLAB C18 linker script file shown below demonstrates the required modifications when building the MPLAB C18 application source code files The linker will use this configuration to link the compiled source code into the user_code program memory region specified at 082Ah above the protected boot loader region Id 18 8722 1kr v 1 2 2004 09 13 22 07 05 curtiss Exp File 18 8722 1kr Sample linker script for the PIC18F8722 proces
9. These operands and instructions only have meaning when an object file is generated they cannot be used when generating absolute code EXAMPLE 6 3 GENERAL OPERAND USE The general operands 1ow high and upper may be used to access data in tables The following code example was taken the p18demo asm file provided with PICDEM 2 Plus demo board The excerpt shows how Microchip is read from the table and displayed on the demo board LCD include p18f452 inc PROG1 CODE stan table table for standard code x XXXXXXXXXXXXXXXX ptr data n Voltmeter 0 data Buzzer 16 data Temperature 32 data Clock 48 data RA4 Next RBO Now 64 data Microchip 80 data PICDEM 2 PLUS 96 data RA4 Set RBO Menu 142 data RA4 RBO 128 data RBO Exit 144 data Volts n 160 data Prd 128 DC 128 176 O 2005 Microchip Technology Inc DS33014J page 145 Assembler Linker Librarian User s Guide p took kok ok kkk STANDARD CODE MENU SELECTION X Xd4 ko kk kkk kk k k movlw 80 send Microchip to LCD movwf ptr pos call stan char 1 Standard code Place characters on line 1 stan char 1 call LCDLine 1 move cursor to line 1 movlw 16 1 full line of LCD movwf ptr count movlw UPPER stan table use operands to load movwf TBLPTRU table pointer values movlw HIGH stan table movwf TBLPTRH movlw LOW stan table movwf TBLPTRL movf ptr
10. p 97 maxrom Define Maximum ROM Location p 98 cblock Define a Block of Constant ooonccccnnncccnncccconcncnnnncnnnncccnnnnnnanccnno p 54 da Store Strings in Program Memory PIC12 16 MCUs p 61 data Create Numeric and Text Data ssssseeee p 62 db Declare Data of One Byte p 65 de Declare EEPROM Data Byte ssssssssseeeeen p 67 dt Define Table PIC12 16 MCUS nan nnnnnncn p 70 dw Declare Data of One Word p 70 endc End an Automatic Constant Block p 72 fill Specify Program Memory Fill Value esses p 82 res Reserve Memory Mr TES p 107 DS33014J page 46 2005 Microchip Technology Inc Directives 4 2 4 Listing Directives Listing directives control the MPASM assembler listing file format These directives allow the specification of titles pagination and other listing control Some listing directives also control how code is assembled e error Issue an Error Message p 74 e errorlevel Set Message Level p 76 list Listing OPTIONS ecoute eet e on e uas p 93 e messg Create User Defined Message p 98 e nolist Turn off Listing Output c ooococinccccnnnccannccccnnnrnnnnrn cnn nono nonnc canaria p 100 page Insert Listing Page Eject eeessseeeeseeeeeeneeee p 103 space Insert Blank Listing Li
11. essssssssss 110 4 60 title Specify Program Title usina caido id 111 4 61 udata Begin an Object File Uninitialized Data Section 111 4 62 udata acs Begin an Object File Access Uninitialized Data Section PIC 18 MCUS coococonoccccnoccconaccnconnncnnncnnnancnconncconncnnnnncncnnnno 112 4 63 udata ovr Begin an Object File Overlaid Uninitialized DAS MINA da A 114 4 64 udata_shr Begin an Object File Shared Uninitialized Data Section PIGTATO MCUS Hm 116 4 65 undefine Delete a Substitution Label 117 4 66 variable Declare Symbol Variable oooocconnocccnnnoccccnnoncccccconannnnncnnnnos 118 4 67 while Perform Loop While Condition is True sssesesssse 119 Chapter 5 Assembler Examples Tips and Tricks COS HALL 1510 VO 110 e T A e a E E ened RE 123 5 2 Example of Displaying Count on Ports oocoonoccccnnnnccccccconccccnnnancconnnnancnnnnnn nos 124 5 3 Example of PORTB Toggle and Delay Routines sssssssss 125 5 4 Example of Calculations with Variables and Constants 132 5 5 Example of a 32 Bit Delay Routine ooooconncnnnnncccccccnnoncnncccnnonnnnnanncccnnnnnnnn 134 5 6 Example of SPI Emulated in Firmware eene 136 5 7 Example of Hexadecimal to ASCII Conversion 138 5 8 Other Sources of Examples ocooocccc
12. MICROCHIP MPASM Assembler MPLINK Object Linker MPLIB Object Librarian User s Guide 2005 Microchip Technology Inc Note the following details of the code protection feature on Microchip devices Microchip products meet the specification contained in their particular Microchip Data Sheet Microchip believes that its family of products is one of the most secure families of its kind on the market today when used in the intended manner and under normal conditions There are dishonest and possibly illegal methods used to breach the code protection feature All of these methods to our knowledge require using the Microchip products in a manner outside the operating specifications contained in Microchip s Data Sheets Most likely the person doing so is engaged in theft of intellectual property Microchip is willing to work with the customer who is concerned about the integrity of their code Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their code Code protection does not mean that we are guaranteeing the product as unbreakable Code protection is constantly evolving We at Microchip are committed to continuously improving the code protection features of our products Attempts to break Microchip s code protection feature may be a violation of the Digital Millennium Copyright Act If such acts allow unauthorized access to your software or other copyrighted work
13. 2005 Microchip Technology Inc W Warnings Assembler eis rutas und 163 COFF to COD Converter eeeeese 222 Lin Keri ditat dee rare Moo lena de 220 Watch Window 133 Web Site Microchip sess 6 WIIG voto cita la co cala mu De A eee 119 White Space etiem cto cete 24 Windows Shell Interface 32 DS33014J page 269 MICROCHIP WORLDWIDE SALES AND SERVICE AMERICAS Corporate Office 2355 West Chandler Blvd Chandler AZ 85224 6199 Tel 480 792 7200 Fax 480 792 7277 Technical Support http support microchip com Web Address www microchip com Atlanta Alpharetta GA Tel 770 640 0034 Fax 770 640 0307 Boston Westborough MA Tel 774 760 0087 Fax 774 760 0088 Chicago Itasca IL Tel 630 285 0071 Fax 630 285 0075 Dallas Addison TX Tel 972 818 7423 Fax 972 818 2924 Detroit Farmington Hills MI Tel 248 538 2250 Fax 248 538 2260 Kokomo Kokomo IN Tel 765 864 8360 Fax 765 864 8387 Los Angeles Mission Viejo CA Tel 949 462 9523 Fax 949 462 9608 San Jose Mountain View CA Tel 650 215 1444 Fax 650 961 0286 Toronto Mississauga Ontario Canada Tel 905 673 0699 Fax 905 673 6509 ASIA PACIFIC Australia Sydney Tel 61 2 9868 6733 Fax 61 2 9868 6755 China Beijing Tel 86 10 8528 2100 Fax 86 10 8528 2104 China Chengdu Tel 86 28 8676 6200 Fax 86 28 8676 6599 China Fuzhou Tel 86 591
14. org 0x0200 The following code section will be programmed starting from address 200H int lo A Write your low priority interrupt service routine here retfie Return from interrupt org 0x1000 You can create a data or character table starting from any address in program memory In this case the address is 1000h ch tbl1 db PICwithFLASH end 4 51 page INSERT LISTING PAGE EJECT 4 51 1 Syntax page 4 51 2 Description and Usage Inserts a page eject into the listing file This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation 4 51 3 See Also list subtitle title 4 52 pagesel GENERATE PAGE SELECTING CODE PIC10 12 16 MCUs 4 52 4 Syntax pagesel label 4 52 2 Description An instruction to the linker to generate page selecting code to set the page bits to the page containing the designated 1abe1 Only one 1abe1 should be specified No operations can be performed on label 1abe1 must have been previously defined The linker will generate the appropriate page selecting code For 12 bit instruction width PIC10F some PIC12 PIC16 devices the appropriate bit set clear instructions on the STATUS register will be generated For 14 bit instruction width most PIC12 PIC16 devices a combination of BSF and BCF commands will be used to adjust bits 3 and 4 of the PCLATH register If the device contains only one p
15. 2005 Microchip Technology Inc Directives udata 0xa0 res 1 bank1 var varl udata 0x120 res 1 bank2 var var2 udata 0xla0 res 1 bank3 var var3 RST CODE 0x0 start start pagesel goto PGM CODE start banksel movlw varo 0x00 movwf var banksel movlw vari 0x01 movwf var banksel movlw var2 0x02 movwf var banksel movlw var3 0x03 movwf var goto end Declares beginning of a data section named banki_var which is in banki vari is allocated the addess 0xa0 Declares beginning of a data Section named bank2 var which is in bank2 var2 is allocated the addess 0x120 Declares beginning of a data Section named bank3 var which is in bank3 var3 is allocated the addess 0x1a0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST Jumps to the location labelled p start This is the begining of the code section named PGM It is a relocatable code section Since no absolute address is given along with directive CODE Select banko var is accessible from banko Select banki var is accessible from bank also Select bank2 var is accessible from bank2 also Select bank3 var is accessible from bank3 also Go to current line loop here 4 65 undefine DELETE A SUBSTITUTION LABEL 4 65 1 undefine l
16. Assembler Examples Tips and Tricks 5 3 4 Register and Bit Assignments You can specify your own registers and bits by using the udata res and equ directives as is done in the following lines udata Declare storage of RAM variables DTEMP res 1 Reserve 1 address location DFLAG res 1 Reserve 1 address location DFLO equ 0x00 Set flag bit 0 bit of DFLAG DTEMP and DFLAG are each assigned one address location in RAM by the linker For illustrative purposes suppose the locations selected by the linker are the general purpose registers GPRs 0x20 and 0x21 DFLO is assigned the value 0x00 and will be used as the name for pin O in the DFLAG register FIGURE 5 1 PIC16F877A REGISTER FILE MAP Special xDD Function lt Registers ADCONO Ox1F DTEMP 0x20 General DFLAG i 0x21 Purpose Registers DFLO Ke Ox7F Bank 0 Bank 1 Bank 2 Bank 3 The directives udata and res are used in relocatable code to define multiple registers instead of equ For more on these directives see Section 4 61 udata Begin an Object File Uninitialized Data Section Section 4 56 res Reserve Memory Section 4 27 equ Define an Assembler Constant 5 3 5 Program Memory CODE Sections and Paging The code directive is used to specify sections of relocatable code For absolute code the org directive is used See Chapter 6 Relocatable Objects for more onthe differ
17. MAIN Main Application Code 0x07FF 13 3 4 Fixing the Error There are several ways to change the linker script that would allow the build to succeed 1 If you want the INT VECTOR code section to be in protected memory change the linker script definition of vectors to CODEPAGE NAME vectors START 0x0000 END 0x001F PROTECTED and the start address of the next section pageo to CODEPAGE NAME page0 START 0x0020 END 0x07FF DS33014J page 194 2005 Microchip Technology Inc Sample Applications 2 Ifyou wantthe INT VECTOR code section to be in unprotected memory change the linker script definition of vectors to CODEPAGE NAME vectors START 0x0000 END 0x0003 PROTECTED and the start address of the next section pageo to CODEPAGE NAME page0 START 0x0004 END 0x07FF 3 Ifthe vectors region is not needed delete the definition from the linker script and change the linker script definition of pageo to CODEPAGE NAME pageO START 0x0000 END 0x07FF 13 4 SAMPLE APPLICATION 2 PLACING CODE AND SETTING CONFIG BITS This example is for the PIC18F8720 in extended microcontroller mode The file eeprom2 asm places interrupt handling code at 0x20000 external memory The assembly code directive INTHAND CODE places the code that follows into the INTHAND section The linker script file eeprom 1kr maps the INTHAND section to the CODE region that begins at 0x20000 The file eeprom1 c has a 0x1000 element
18. ORG 0x0000 The following code will be programmed in reset address 0 goto start Jump to an address labelled start start Write your main program here goto Go to current line loop here ORG 0x1000 Store the string starting from 1000H In PIC18 devices the first character is in least Significant byte Ch_stng data M C U 3 program memory locations will be filled with ASCII equivalent of M C and UU Directive data produces three 16 bit numbers 004Dh 0043h and 0055h 4Dh 43h and 55h are ASCII equivalents of M C and U respectively See Section 4 10 code pack Begin an Object File Packed Code Section PIC18 MCUS for better use of memory Ch stgl data MCU 2 program memory locations Will be filled with two words 16 bit numbers each representing ASCI equivalent of two characters The last character will be taken as NULL in case odd number of characters are specified Directive data produces two words 434Dh and 0055h 434Dh represents C and M tb1 dta data Oxffff 0xaa55 Places ffff and aa55 in two consecutive program memory locations end DS33014J page 64 2005 Microchip Technology Inc Directives 4 16 db DECLARE DATA OF ONE BYTE 416 1 Syntax label db expr expr expr 4 16 2 Description db Data Byte Reserve program memory words with 8 bit values Multiple expressions continue to fill bytes consecutively until the end of
19. Some operators and pseudo operators take section names as operands The lexical form of a section name is that of an identifier optionally prefixed with a 163 CONFIG directives must be contiguous Do not place other code between _ config directive declarations 164 IDLOC directives must be contiguous Do not place other code between idloc directive declarations 165 extended mode not available for this device This PIC18 device does not support extended mode 166 left bracket missing from offset operand The left bracket is missing from an offset i e 0x55 167 right bracket missing from offset operand The right bracket is missing from an offset i e 0x55 168 square brackets required around offset operand Square brackets are required around an offset i e 0x55 169 access bit cannot be specified with indexed mode When using indexed mode the access bit cannot be specified 170 expression within brackets must be constant The expression specified within brackets is not a constant value 171 address specified is not in access ram range of 0x60 OxFF When making use of Access RAM addressing must occur within the specified Access Bank range DS33014J page 162 2005 Microchip Technology Inc Errors Warnings Messages and Limitations 172 PCL TOSL TOSH or TOSU cannot be destinatin of MOVFF or MOVSF These registers cannot be written to with mov f or movsf commands 173 source file path excee
20. Subroutine goto DoDly32 movlw addwf btfsc clrw addwf btfsc clrw addwf btfsc clrw addwf btfsc clrw iorwf iorwf iorwf iorwf btfss goto retlw END TestCode Go back to top of program and run the delay again called by the Macro Dly32 20 Tcy per loop H FF DlyO F STATUS C Dly1 F STATUS C Dly2 F STATUS C Dly3 F STATUS C DlyO W Dly1 W Dly2 W Dly3 W STATUS Z DoDly32 0 Start with 1 in W LSB decrement was the carry flag set If so 0 is put in W Else we continue 0 in W 0 in W 0 in W Inclusive OR all variables together to see if we have reached 0 on all of them Test if result of Inclusive OR s is 0 It was NOT zero so continue counting It WAS zero so exit this subroutine 2005 Microchip Technology Inc DS33014J page 135 Assembler Linker Librarian User s Guide 5 6 EXAMPLE OF SPITM EMULATED IN FIRMWARE Directives highlighted in this example are list e define udata res global 5 6 1 Program Functional Description This program is used to emulate SPI function in firmware The application is written as relocatable code i e you must use both the assembler and linker to generate the executable The list directive is used to define the processor and set listing file formatting The standard header file for the processor selected is included using include SPI variables are declared using define
21. The file may be corrupted Could not write member header for memberName in library file filename The file may be corrupted File filename is not a valid library file Library files must end with 1ib Library file filename has a missing member object file The file not a valid object file or it may be corrupted memberName is not a member of library filename memberName can not be extracted or deleted from a library unless it is a member of the library DS33014J page 220 2005 Microchip Technology Inc Errors Warnings and Common Problems Symbol symName has multiple external definitions A symbol may only be defined once in a library file 14 6 COFF FILE ERRORS All the COFF errors listed below indicate an internal error in the file s contents Please contact Microchip support if any of these errors are generated Coff file filename could not read file header Coff file filename could not read line numbers Coff file filename could not read optional file header Coff file filename could not read raw data Coff file filename could not read relocation info Coff file filename could not read section header Coff file filename could not read string table Coff file filename could not read string table length Coff file filename could not read symbol table Coff file filename could not write file header Coff file filename could not write linein
22. testing output string two B061 moviw a 7465 7374 696E data testing first output string 6720 6669 7273 7420 6F75 7470 7574 2073 7472 696E 6700 OE s M m J sosc A an 5 DS33014J page 40 2005 Microchip Technology Inc Expression Syntax and Operation 3 3 RESERVED WORDS AND SECTION NAMES You may not use the following words for label constant or variable names Directives see Chapter 4 Directives Instructions see Appendix A Instruction Sets In addition the assembler has the following reserved section names TABLE 3 2 RESERVED SECTION NAMES Section Name Purpose access ovr Default section name for access ovr directive code Default section name for code directive idata Default section names for idata and idata acs directives idata acs respectively udata Default section names for udata udata acs udata ovr and udata acs udata shr directives respectively udata ovr udata shr 3 4 NUMERIC CONSTANTS AND RADIX MPASM assembler supports the following radix forms for constants hexadecimal decimal octal binary and ASCII The default radix is hexadecimal the default radix determines what value will be assigned to constants in the object file when a radix is not explicitly specified by a base descriptor Note Ther
23. Library File lib A collection of object files grouped together for convenience Linker Script File Ikr Description of memory layout for a particular processor project Output Files COFF Object Module File Debug file used by MPLAB IDE v6 xx and later cof out Symbol and Debug File cod Debug file used by MPLAB IDE v5 xx and earlier Hex File Formats hex hxl Hexidecimal file with no debug information Suitable for use in hxh programming Listing File Ist Original source code side by side with final binary code Note Requires linker can find original source files Map File map Shows the memory layout after linking Indicates used and unused memory regions Sa cA C C A d M r rc is 2005 Microchip Technology Inc DS33014J page 173 Assembler Linker Librarian User s Guide 9 7 1 Object File 0 Object files are the relocatable code produced from source files The MPLINK linker combines object files and library files according to a linker script into a single output file Object files may be created from source files by MPASM assembler and library files may be created from object files by MPLIB librarian 9 7 2 Library File lib Libraries are a convenient
24. Once MPLAB IDE is installed on your PC check the settings below to ensure that the language tools are properly recognized under MPLAB IDE 1 From the MPLAB IDE menu bar select Project gt Set Language Tool Locations to open a dialog to set check language tool executable location FIGURE 1 SET LANGUAGE TOOL LOCATIONS set Language Tool Locations x r Registered Tools Microchip C17 Toolsuite Microchip C18 Toolsuite E Microchip C30 Toolsuite E Microchip MPASM Toolsuite E Executables MPASM Assembler mpasmwin exe MPLIB Librarian mplib exe MPLINK Object Linker mplink exe Default Search Paths amp Directories E microEngineering PicBasic Pro Toolsuite E microE ngineering PicBasic T oolsuite v Location C Program Files MPLAB IDEAMCHIP_T oolsimpasmwin exe Browse Help DK Cancel Apply 2 Inthe dialog under Registered Tools select Microchip MPASM Toolsuite Click the to expand 3 Select Executables Click the to expand 4 Select MPASM Assembler mpasmwin exe Under Location a path to the executable file should be displayed If no path is displayed enter one or browse to the location of this file The default location is listed in MPLAB IDE and Tools Installation 5 Select MPLINK Object Linker mp1ink exe Under Location a path to the executable file should be displayed If no path is displayed enter one o
25. VECTOR MAPPING SSA extern void startup void See co18i c in your C18 compiler dir pragma code RESET INTERRUPT VECTOR 0x000800 void reset void pragma code HIGH INTERRUPT VECTOR 0x000808 void high ISR void _asm goto startup _endasm pragma code LOW INTERRUPT VECTOR 0x000818 void low ISR void APPLICATION CODE kk FO kk ko kk ek IO koe ARRAY 1 pragma code void main void while 1 i Main application code here END OF APPLICATION NA O 2005 Microchip Technology Inc DS33014J page 201 Assembler Linker Librarian User s Guide Id File 13 5 7 Mixed Language MPLAB C18 Application Linker Script The partial MPLAB C18 linker script file shown below demonstrates the required modifications when building the mixed MPASM boot loader MPLAB C18 application The linker will use this configuration to link the compiled source code into the user program memory region above the protected boot loader In this linker script example the MPLAB C18 start up file co181i o has been remarked out preventing the linker from linking this object file to the project 18 8720 1kr v 1 2 2004 09 13 22 07 05 curtiss Exp 18 8720 1kr Sample linker script for the PIC18F8720 processor LIBPATH FILES c018i o FILES clib lib lt Note this line to be ignored by linker FILES p18f8720 1ib CODEPAGE CODEPAGE CODEPAGE
26. 71 422 end End Program BIOGK essa 71 4 23 ende End an Automatic Constant Block ssssssseess 72 4 24 endif End Conditional Assembly Block sesseesssss 72 4 25 endm End a Macro Definition simon eg iren ree ae 73 4 26 endw End a while Loop tii 73 4 27 equ Define an Assembler Constant cccccccessssseeeeeeeeesesnsneeeeeeeess 74 4 28 error Issue an Error Message esee 74 4 29 errorlevel Set Message Level ssssssseeeeee 76 4 30 exitm Exit from a Macro ei eS ais 78 4 31 expand Expand Macro Listing 3 iren rine antenne 80 4 32 extern Declare an Externally Defined Label 80 4 33 i11 Specify Program Memory Fill Value eeeesesesss 82 4 34 global Export a Label eint sleds ass 84 4 35 idata Begin an Object File Initialized Data Section 85 4 36 idata acs Begin an Object File Initialized Data Section in Access RAM PIC18 MCUs cuicos terere Pete ni loe Sr epe 86 4 37 _ tdloes Set Processor ID Locations trea 87 4 38 if Begin Conditionally Assembled Code Block ssssse 88 4 39 ifdef Execute If Symbol has Been Defined sssssssss 90 4 40 ifndef Execute If Symbol has not Been Defined 91 4 41
27. Assembly will be enabled or disabled until the next matching else or endif directive is encountered 4 40 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is not an instruction but used to control how code is assembled not how it behaves at run time Use this directive for removing or adding code during debugging without the need to comment out large blocks of code 4 40 4 See Also Hdefine undefine else endif ifdef 4 40 5 Simple Example define testingl set testing on undefine testingl set testing off ifndef testing if not in testing mode a execute this path endif end end of source 2005 Microchip Technology Inc DS33014J page 91 Assembler Linker Librarian User s Guide 4 40 6 Application Example ifndef include p16f877a inc Hdefine UsePORTB Comment out with to use PORTC Hifndef UsePORTB MyPort equ PORTC Use Port C if USePORTB not defined MyTris equ TRISC TRISC must be used to set data direction for PORTC Helse MyPort equ PORTB Use Port B if UsePORTB defined MyTris equ TRISB TRISB must be used to set data direction for PORTB endif banksel MyTris clrf MyTris Set port to all outputs banksel MyPort Return to bank used for port movlw 55h Move arbitrary value to W reg movwf MyPort Load port selected with 55h end 4 41 i
28. Germany Munich Tel 49 89 627 144 0 Fax 49 89 627 144 44 Italy Milan Tel 39 0331 742611 Fax 39 0331 466781 Netherlands Drunen Tel 31 416 690399 Fax 31 416 690340 Spain Madrid Tel 34 91 352 30 52 Fax 34 91 352 11 47 UK Wokingham Tel 44 118 921 5869 Fax 44 118 921 5820 07 01 05 DS33014J page 270 2005 Microchip Technology Inc
29. See the standard header p18 452 inc for a complete list of symbols MPASM 03 70 Released SOURCE ASM 4 5 2004 15 40 00 PAGE 1 LOC OBJECT CODE LINE SOURCE TEXT VALUE 00001 list p 18f452 00002 include p18f452 inc 00001 LIST 00002 P18F452 INC Standard Header File Version 1 4 00845 LIST 0000000B 00003 Dest equ OxOB 00004 000000 00005 org 0x0000 000000 EF10 F000 00006 goto Start 000020 00007 org 0x0020 000020 OEOA 00008 Start movlw Ox0A 000022 6EOB 00009 movwf Dest 000024 960B 00010 bcf Dest 3 This line uses 2 op 000026 EF10 F000 00011 goto Start 00012 end MPASM 03 70 Released SOURCE ASM 4 5 2004 15 40 00 PAGE 2 SYMBOL TABLE LABEL VALUE A 00000000 ACCESS 00000000 XT OSC 1H 000000F9 18F452 00000001 MPASM 03 70 Released SOURCE ASM 4 5 2004 15 40 00 PAGE 12 MEMORY USAGE MAP X Used Unused 0000 XXXX OOO So 25 sh 5ssesseeedesee All other memory blocks unused Program Memory Bytes Used 14 Program Memory Bytes Free 32754 SES 2005 Microchip Technology Inc DS33014J page 27 Assembler Linker Librarian User s Guide Errors i 0 Warnings 0 reported 0 suppressed Messages 0 reported 0 suppressed 1 7 4 Error File err The MPASM assembler by default generates an error file This file can be useful when debugging your code The MPLAB IDE will display the error information in the Output window The format of the messages in the error file is type n
30. The if endif code outputs error and messg if the baud rate selected is other than 1200 2400 4800 9600 or 19200 Hz RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start a Start PGM CODE This is the begining of the code section named PGM It is a relocatable code section Since no absolute address is given along with directive CODE start goto Go to current line loop here end 2005 Microchip Technology Inc DS33014J page 99 Assembler Linker Librarian User s Guide 4 48 noexpand TURN OFF MACRO EXPANSION 4 48 1 Syntax noexpand 4 48 2 Description and Usage Turns off macro expansion in the listing file This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation 4 48 3 See Also expand 4 49 nolist TURN OFF LISTING OUTPUT 4 49 1 Syntax nolist 4 49 2 Description and Usage Turn off listing file output This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation 4 49 3 See Also list 4 50 org SET PROGRAM ORIGIN 4 50 4 Syntax 1abel org expr 4 50 2 Description Set the program origin for subsequent code at the address defined in expr If label is
31. Two sections in the same source file are not permitted to have the same name 4 63 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation This directive is similar to udata except that it allows you to reuse data space by overlaying one data area on another It is used for temporary variables as each data section may overwrite and thus share the same RAM address locations 4 63 4 See Also extern global idata udata udata acs udata shr DS33014J page 114 2005 Microchip Technology Inc Directives 4 63 5 Simple Example Temps udata ovr Tempi res 1 Temp2 res 1 Temp3 res 1 Temps udata ovr LongTempl res 2 this same 1 LongTemp2 res 2 this Same 1 4 63 6 will be a variable at the ocation as Templ and Temp2 will be a variable at the ocation as Temp3 Application Example udata ovr This program demonstrates the udata ovr directive This directive declares the beginning of a section of overlaid uninitialized data include p16f877a inc same var vari same var var2 RST pagesel goto PGM start udata ovr res 1 udata ovr res 1 CODE 0x0 start start CODE banksel varl movlw movwf OxFF varl comf var2 goto end 0x20 0x20 Include standard header file for the selected device Declares an overlayed uninitialized data secti
32. While there is no direct provision for continuation onto a second line it is generally no problem to use a second dw directive for the next line The dw directive will store the entire string into successive words If a string has an odd number of characters bytes the dw and data directives will pad the end of the string with one byte of zero 00 If a string is used as a literal operand it must be exactly one character long or an error will occur 2005 Microchip Technology Inc DS33014J page 39 Assembler Linker Librarian User s Guide 3 2 1 Escape Characters The assembler accepts the ANSI C escape sequences to represent certain special control characters TABLE 3 1 ANSI C ESCAPE SEQUENCES Escape Description Rex Character Value a Bell alert character 07 b Backspace character 08 Form feed character oc n New line character OA Nr Carriage return character OD t Horizontal tab character 09 v Vertical tab character 0B NN Backslash 5C Question mark character 3F Single quote apostrophe 27 Yr Double quote character 22 000 Octal number zero Octal digit Octal digit xHH Hexadecimal number 3 2 2 Code Examples See the examples below for the object code generated by different statements involving strings 7465 7374 696E dw testing output string one n 6720 6F75 7470 7574 2073 7472 696E 6720 6F6E 650A define str
33. You can create a data or character table starting from any address in EE data memory ch tbl2 de PICmicro 6 EE data memory locations starting from 0 will be filled with 6 ASCIT characters end 4 17 7 PIC18 Application Example de include p18f452 inc Include standard header file for the selected device org 0xF00000 The absolue address F00000h is mapped to the 0000 location of EE data memory for PIC18 devices You can create a data or character table starting from any address in EE data memory ch tbl2 de PICmicro 6 EE data memory locations starting from 0 will be filled with 6 ASCII characters end DEFINE A TEXT SUBSTITUTION LABEL 4 18 4 Syntax Hdefine name string 4 18 2 Description This directive defines a text substitution string Wherever name is encountered in the assembly code string will be substituted Using the directive with no string causes a definition of name to be noted internally and may be tested for using the ifdef directive This directive emulates the ANSI C standard for def ine Symbols defined with this method are not available for viewing using MPLAB IDE 4 18 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation DS33014J page 68 2005 Microchip Technology Inc Directives define is useful for defining va
34. eode inner 106 ize S 106 POSER en lentes Aer erre eue di 108 A mi ire melti Re vies aie de 109 SPaCO sii a ware anus 48 110 A E E EE ET 111 TRIG ite abe E E deat 111 Udala 112 udata a6S iiie eR 113 data OVI fue end ede 114 Udata Shri sien Ra 116 variable ricco ioi ree de dr dite 118 A ERR e eee ete rend 120 Executable Files 12 Execute If Symbol Defined ss 90 Execute If Symbol Not Defined 91 AI rss RORIS 78 XPANG MDC M 80 Exporta Label sas 84 Extended Microcontroller Mode 195 EXTERNE S Vt D M ELT nr 80 148 External Labels o stie deos 80 F Mat apto o T EUER 72 File A msn c tante da E eiae us 157 LIS ina ad 47 FIRES on atorado ne dr 182 A tieni Molanus Pen UR ne a 82 Final Frontier 110 G global nn entrant dai 84 H Header Files 92 128 143 Hex Files 2 E 12 28 174 l ID EoCatlons u insu to e Pet chu tt 87 148 6 T sott omittere 85 147 A headed 86 IGIOES dup MERE 87 C EE 88 else uve RE PETENTE ne RT TENUES 71 lom 1 72 AB E 90 dv EE 91 INCLUDE tddi 183 IICA e 92 Include Additional Source File 92 Include File 26 Incremento cred ree oed e DN EE 43 Initialized Data 190 Input Output Files Assembl f 2 525 Bine a ced tiii 24 Librarian niii te tefie rpi oreet P rna Ced
35. include Include Additional Source File ssessssss 92 4 42 Tist Listing Opodo ue hisce todas haa cete Et ee 93 4 43 local Declare Local Macro Variable sseeseeeeesess 94 4 44 macro Declare Macro Definition 96 4 45 maxram Define Maximum RAM Location 97 4 46 maxrom Define Maximum ROM Location sene 98 4 47 messg Create User Defined Message sse 98 4 48 noexpand Turn off Macro Expansion eeeeeeeee 100 4 49 nolist Turn off Listing Output sseeeee 100 4 50 org Set Program Origin una ad 100 4 51 page Insert Listing Page Eject 5 Rama 103 4 52 pagesel Generate Page Selecting Code PIC10 12 16 MCUs 103 2005 Microchip Technology Inc Table of Contents 4 53 pageselw Generate Page Selecting Code Using WREG Commands PIC 02 10 MOLIS oa Ra e iR isa esci a Ee Ne 105 4 54 processor Set Processor Type sse 106 4 55 radix Specify Default Radix sas haine 106 4 56 res Reserve Memo isa Haass epu de ror Kc in amenant 107 4 57 set Define an Assembler Variable 109 4 58 space Insert Blank Listing Lines esee 110 4 59 subtitle Specify Program Subtitle
36. isr code 0x08 Interrupt Service Routine Servint banksel OPTION REG Select Option Reg Bank 1 bsf OPTION REG TOCS Stop Timer0 banksel INTCON Select INTCON Bank 0 bcf INTCON TOIF Clear overflow flag bcf DFLAG DFLO Clear flag bit retfie Return from interrupt For the PIC16F877A there is not enough memory to add a pagesel ServInt statement to insure proper paging Therefore the ISR code needs to be specifically placed on page 0 See Section 5 3 7 Interrupts for more on the ISR code PRR RRR RRR KKK kc ke ke e he ke ke ke ke ke ke kkk ke e ke ke ke e he ke kkk k k k k Main Program PRR RRR kkk KKK KER KERR k kkk k ke ke e he k e ke k k k k kk kk k k k k code Start Program Begin program code Because no address is specified the program memory location will be determined by the linker See Section 5 3 5 Program Memory CODE Sections and Paging for more on code DS33014J page 126 2005 Microchip Technology Inc Assembler Examples Tips and Tricks Start clrf banksel clrf banksel bsf bsf PORTB TRISB TRISB INTCON INTCON GIE INTCON TOIE Clear PortB Select TRISB Bank 1 Set all PortB pins as outputs Select INTCON Bank 0 Enable Global Int s Enable Timer0 Int First set up PORTB pins to be all outputs using the data direction TRISB register Then set up Timer 0 and interrupts for later use Loop movlw movwf Call clrf pagesel Call pagesel got
37. it can analyze all the input files and try to fit the application s routines into ROM and assign its data variables into available RAM If there is too much code or too many variables to fit the linker will give an error message The MPLINK linker also provides flexibility for specifying that certain blocks of data memory are reusable so that different routines which never call each other and which don t depend upon this data to be retained between execution can share limited RAM space When using a C compiler libraries are available for most PICmicro MCU peripheral functions as well as for many standard C functions The linker will only extract and link individual object files that are needed for the current application from the included libraries This means that relatively large libraries can be used in a highly efficient manner The MPLINK linker combines all input files to generate the executable output and ensures that all addresses are resolved Any function in the various input modules that attempts to access data or call a routine that has not been allocated or created will cause the linker to generate an error The MPLINK linker also generates symbolic information for debugging your application with MPLAB IDE cof 1st and map files LINKER INPUT OUTPUT FILES The MPLINK linker combines multiple object files into one executable hex file Input Files Object File 0 Relocatable code produced from a source file
38. moviw Oxff as output movwf TRISB else clrw If config 0x0 is false movwf TRISB assemble the mnemonics up to moviw Oxff the directive endif Set up PORTB movwf TRISA as output endif goto Go to current line loop here end 2005 Microchip Technology Inc DS33014J page 89 Assembler Linker Librarian User s Guide 4 39 ifdef EXECUTE IF SYMBOL HAS BEEN DEFINED 4 39 1 Syntax Preferred ifdef label Supported Hifdef label 4 39 2 Description If 1abe1 has been previously defined usually by issuing a define directive or by setting the value on the MPASM assembler command line the conditional path is taken Assembly will continue until a matching else or endif directive is encountered 4 39 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is not an instruction but used to control how code is assembled not how it behaves at run time Use this directive for removing or adding code during debugging without the need to comment out large blocks of code 4 39 4 See Also Hdefine undefine else endif ifndef 4 39 5 Simple Example define testing 1 set testing on ifdef testing lt execute test code gt this path would be executed endif 4 39 6 Application Example ifdef include p16f877a inc define AlternateASM Comment out with if extra features not des
39. start add is a macro The values of numl and num2 must be passed to this macro If numl gt 255 decimal force immediate return from macro during assembly If num2 gt 255 decimal force immediate return from macro during assembly Load W register with a literal value assigned to the label numl Load W register to an address location assigned to the label result Load W register with a literal value assigned to the label num2 Add W register with the memory location addressed by result and load the result back to result End of add MACRO My main program starts at 10H The label start is assigned an address 10H Call add MACRO with decimal numbers 100 and 256 assigned to numl and num2 labels respactively EXTIM directive in macro will force return Remember means decimal not floating point 2005 Microchip Technology Inc DS33014J page 79 Assembler Linker Librarian User s Guide 4 31 expand EXPAND MACRO LISTING 4 31 1 Syntax expand 4 31 2 Description Expand all macros in the listing file This directive is roughly equivalent to the m MPASM assembler command line option but may be disabled by the occurrence of a subsequent noexpand 4 31 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This di
40. user void main void DS33014J page 4 2005 Microchip Technology Inc Preface RECOMMENDED READING This documentation describes how to use Assembler Linker Librarian User s Guide Other useful documents are listed below The following Microchip documents are available and recommended as supplemental reference resources Readme Files readme asm and readme lkr For the latest tool information and known issues see the MPASM assembler readme file readme asm or the MPLINK object linker MPLIB object librarian readme file readme 1kr These ASCII text files may be found in the Readme folder of the MPLAB IDE installation directory On line Help Files Comprehensive help files are available for MPASM assembler and MPLINK object linker MPLIB object librarian MPASM and MPLINK PICmicro Quick Reference Card DS30400 A quick reference card QRC is available containing an MPASM assembler directive language summary MPASM assembler radix types supported MPLINK object linker command line options MPLIB object librarian usage format and examples PIC18 device special function register files ASCII character set and PlCmicro MCU instruction set summaries C Compiler User s Guides and Libraries The MPLINK linker and MPLIB librarian also work with the Microchip C language compiler MPLAB C18 for PIC18 devices For more information on MPLAB C18 see MPLAB C18 C Compiler Getting Started DS51295 MPLAB
41. x Disable x path Enable specify path See Section 1 7 6 Cross Reference File xrf for more information yl 1 Disabled Enable Disable extended instruction set y Enable y Enable y Disable Can only be enabled for processors which support the extended instruction set and for the generic processor PIC18CXXX y overrides LIST PE type directive see Section 4 42 1ist Listing Options Default is dependent on processor selected HH c 7 u A A siqua t DS33014J page 36 2005 Microchip Technology Inc Assembler Interfaces 2 6 TROUBLESHOOTING If you are using mpasm exe and get a message saying that you have run out of environment space use Microsoft Windows Internet Explorer to select the mpasm exe file in the MPLAB IDE installation directory and click on the right mouse button to bring up the Properties dialog FIGURE 2 3 PROPERTIES DIALOG MPASM EXE mP asmExE Properties alx Screen Misc Compatibility Summary General Program Font Memory M Conventional memory Initial Total Auto v environment EE X Auto Protected 256 TUE 512 Expanded EMS memory 768 1024 Total None bd 1280 1536 1792 Extended XMS memory 2304 Total o Y 2560 2816 IV Uses HMA 3072
42. 100 Text Substitution ccmcoocococnncnoooconancnnoonnnnos 154 US Ia 154 MAGCIO sica eet tod vedete ede dae etes 96 Macro Directives cccccoocoonnnnccnnnnnnnncnnnonononoronnennnnnns 47 Defined sient et A totis 154 AMA a tn rpm Ans 73 extinctus re nr M Res ae 78 expand cidad 80 Le RE ds rales TI 94 o IM SD M E 96 rioexpand ete edd eere nae 100 Macro Language nrinn nann na 153 Macro Syntax iii ep n 153 Map File iesita iasan en 176 Maximum RAM Location 97 Maximum ROM Location 98 AXE r Ae As ppp DI MM A 97 IARE EEREORHUOEHEI HE 98 MCC INGEUDE emen 192 Memory Ell a sudes e uM een E E 82 Reserve ses 107 Memory Regions 183 Message wii reete tree annees 98 Messages Assembler MESSIEURS IU tu ESSEN MPASM Assembler Overview mpasim exe mn NN nn Sch mpasmwin exe MPLEAB C18 tirer aveces MPLIB Librarian Overview 227 MPLIB Object Librarian eeeeeeeses 12 MPLINK Linker Overview 171 MPLINK Object Linker 12 N noexpald d be ode e e deter aia 100 e 100 NA 43 Oo Object File 30 34 174 229 Object File Directives eseeeeeseesss 47 ACCESS OV T ie icu T eee oh tet in mds ioa 48 bankisel cts n EE ERREUR ch 50 banksel tein epist 52 A das 56 Cde Pack EC 57 EXT A ee A E RS 80 global i tern pt ec em quete 84 A A e Y eeu 85 Idata aCs e ec tetas 86 pagese
43. 16 MCU s fill 0x1009 5 fill with a constant fill GOTO RESET VECTOR NEXT BLOCK Example 2 PIC18 Devices include p18f252 inc org 0x12 failsafe goto org 0x100 fill goto failsafe 0x8000 2 Divide by 2 for 2 word instructions end DS33014J page 82 2005 Microchip Technology Inc Directives 4 33 6 X PIC16 Application Example i11 The 111 directive is used to specify successive program memory locations with a constant or an assembly instruction include p16f877a inc Include standard header file for the selected device RST CODE 0x0000 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start start fill 0 INTRPT Fill with 0 up to address 3 INTRPT addr minus current addr INTRPT CODE 0x0004 The code section named INTRPT is placed at program memory location 0x4 The next two instructions are placed in code section INTRPT pagesel ISR Jumps to the location labelled goto ISR ISR fill goto start start Fill upto address OFh with instruction lt goto start gt CODE 0x0010 start Write your main program here fill nop 5 Fill 5 locations with NOPs goto Go to current line loop here ISR Write your interrupt service retfie routine here end 4 33 7 PIC18 Application Example i1
44. 2 Constant Compare As another example if the following macro were written include pic16f877a inc compare file to constant and jump if file gt constant cfl jge macro file con jump to movlw con amp Oxff subwf file w btfsc status carry goto jump to endm and invoked by cfl jge switch val max switch switch on it would produce movlw max switch amp Oxff subwf switch val w btfsc status carry goto switch on DS33014J page 156 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 8 Errors Warnings Messages and Limitations 8 1 INTRODUCTION Error messages warning messages and general messages produced by the MPASM assembler are listed and detailed here These messages always appear in the listing file directly above each line in which the error occurred Limitations of the assembler tool are also listed The messages are stored in the error file err if no MPASM assembler options are specified If the e option is used turns error file off then the messages will appear on the screen If the q quiet mode option is used with the e then the messages will not display on the screen or in an error file The messages will still appear in the listing file Topics covered in this chapter Assembler Errors Assembler Warnings Assembler Messages Assembler Limitations 8 2 ASSEMBLER ERRORS MPASM assembler errors are listed numerically belo
45. 261 Assembler Linker Librarian User s Guide Symbol A symbol is a general purpose mechanism for describing the various pieces which comprise a program These pieces include function names variable names section names file names struct enum union tag names etc Symbols in MPLAB IDE refer mainly to variable names function names and assembly labels The value of a symbol after linking is its value in memory System Window Control The system window control is located in the upper left corner of windows and some dialogs Clicking on this control usually pops up a menu that has the items Minimize Maximize and Close Target Refers to user hardware Target Application Software residing on the target board Target Board The circuitry and programmable device that makes up the target application Target Processor The microcontroller device on the target application board Template Lines of text that you build for inserting into your files at a later time The MPLAB Editor stores templates in template files Tool Bar A row or column of icons that you can click on to execute MPLAB IDE functions Trace An emulator or simulator function that logs program execution The emulator logs pro gram execution into its trace buffer which is uploaded to MPLAB IDE s trace window Trace Memory Trace memory contained within the emulator Trace memory is sometimes called the trace buffer Trigger Output Trigger output refe
46. 3328 MS DOS protected mode DPMI memory Bein Total Auto X 4096 Cancel Apply Increase the size of the Initial Environment Usually a setting of 2048 will suffice but if you have a lot of applications that set variables and add to your path statement in your AUTOEXEC BAT file you may need to make it larger 2005 Microchip Technology Inc DS33014J page 37 Assembler Linker Librarian User s Guide NOTES DS33014J page 38 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 3 Expression Syntax and Operation 3 1 INTRODUCTION Various expression formats syntax and operations used by MPASM assembler are described here Topics covered in this chapter Text Strings Reserved Words and Section Names Numeric Constants and Radix Arithmetic Operators and Precedence 3 2 TEXT STRINGS A string is a sequence of any valid ASCII character of the decimal range of 0 to 127 enclosed by double quotes It may contain double quotes or null characters The way to get special characters into a string is to escape the characters preceding them with a backslash V character The same escape sequences that apply to strings also apply to characters Strings may be of any length that will fit within a 255 column source line If a matching quote mark is found the string ends If none is found before the end of the line the string will end at the end of the line
47. 4 37 idlocs SET PROCESSOR ID LOCATIONS Note idlocs is preceded by two underline characters 4 37 4 Syntax __idlocs expr idlocs addr expr PIC18 Only 4 37 2 Description For PIC12 and PIC16 devices _ idlocs sets the four ID locations to the hexadecimal value of expr For example if expr evaluates to 1AF the first lowest address ID location is zero the second is one the third is ten and the fourth is fifteen For PIC18 devices idlocs sets the two byte device ID at location addr to the hexadecimal value of expr Before this directive is used the processor must be declared through the command line the 1ist directive or the processor directive 4 37 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is not commonly used but does provide an easy method of serializing devices idlocs can be read by a programmer PIC18 devices can read this value at run time but PIC12 16 devices cannot 4 37 4 See Also _ config config list processor 4 37 5 Simple Example Example 1 PIC16 Devices include p16f877a inc Include standard header file for the selected device idlocs 0x1234 Sets device ID to 1234 2005 Microchip Technology Inc DS33014J page 87 Assembler Linker Librarian User s Guide Example 2 PIC18 Devices Note The most significant nibble of idlocs
48. 4 59 subtitle SPECIFY PROGRAM SUBTITLE 4 59 1 Syntax Preferred subtitle sub_text Supported stitle sub text subtitl sub text DS33014J page 110 2005 Microchip Technology Inc Directives 4 59 2 Description and Usage sub text is an ASCII string enclosed in double quotes 60 characters or less in length This directive establishes a second program header line for use as a subtitle in the listing output This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation 4 59 3 See Also list title 4 59 4 Simple Example subtitle diagnostic section 4 60 title SPECIFY PROGRAM TITLE 4 60 1 Syntax title title text 4 60 2 Description and Usage title text is a printable ASCII string enclosed in double quotes It must be 60 characters or less This directive establishes the text to be used in the top line of each page in the listing file This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation 4 60 3 See Also list subtitle 4 60 4 Simple Example title operational code rev 5 0 4 61 udata BEGIN AN OBJECT FILE UNINITIALIZED DATA SECTION 4 61 1 Syntax 1abel udata RAM address 4 61 2 Description This directive declares the beginning of a section of uninitialized data If 1abe1 is not specified the section is
49. Additionally goto MyLabel will never locate the code at Mylabl or Mylable Check for these sorts of mistakes first As a general rule put your include files at the top of each file If this seems to cluttered you may include files within other include files 114 Divide by zero Division by zero encountered during an expression evaluation 115 Duplicate label A label was declared as a constant e g with the equ or cblock directive in more than one location DS33014J page 158 2005 Microchip Technology Inc Errors Warnings Messages and Limitations 116 Address label duplicated or different in second pass The same label was used in two locations Alternately the label was used only once but evaluated to a different location on the second pass This often happens when users try to write page bit setting macros that generate different numbers of instructions based on the destination 117 Address wrapped around 0 For PIC12 16 devces the location counter can only advance to OxFFFF After that it wraps back to 0 Error 117 is followed by error 118 118 Overwriting previous address contents Code was previously generated for this address 119 Code too fragmented The code is broken into too many pieces This error is very rare and will only occur in Source code that references addresses above 32K including configuration bits 120 Call or jump not allowed at this address A call or jump cannot be made to this addres
50. Application Maestro dsPICDEM dsPICDEM net dsPICworks ECAN ECONOMONITOR FanSense FlexROM fuzzyLAB In Circuit Serial Programming ICSP ICEPIC Linear Active Thermistor MPASM MPLIB MPLINK MPSIM PICkit PICDEM PICDEM net PICLAB PICtail PowerCal Powerlnfo PowerMate PowerTool rfLAB rfPICDEM Select Mode Smart Serial SmartTel Total Endurance and WiperLock are trademarks of Microchip Technology Incorporated in the U S A and other countries SQTP is a service mark of Microchip Technology Incorporated in the U S A All other trademarks mentioned herein are property of their respective companies 2005 Microchip Technology Incorporated Printed in the U S A All Rights Reserved gt Printed on recycled paper Microchip received ISO TS 16949 2002 quality system certification for its worldwide headquarters design and wafer fabrication facilities in Chandler and Tempe Arizona and Mountain View California in October 2003 The Company s quality system processes and procedures are for its PICmicro 8 bit MCUs KEELOG code hopping devices Serial EEPROMs microperipherals nonvolatile memory and analog products In addition Microchip s quality system for the design and manufacture of development systems is ISO 9001 2000 certified DS33014J page ii 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Table of Contents Part 1 MPASM Assembler Chapter 1 MPASM A
51. CODEPAGE CODEPAGE CODEPAGE CODEPAGE CODEPAGE 2 2 2 2 3 2 Zz zz A A A A A A A A i a e oF lt M M E vectors START 0x0 END 0x29 PROTECTED E boot START 0x2A END 0x1FF PROTECTED E rm vectors START 0x200 END 0x229 PROTECTED E user code START 0x22A END 0x1FFFFF E idlocs START 0x200000 END 0x200007 PROTECTED E config START 0x300000 END 0x30000D PROTECTED E devid START 0x3FFFFE END 0x3FFFFF PROTECTED E eedata START 0xF00000 END 0xF003FF 13 5 8 Mixed Language MPLAB C18 c018i c Modifications For a typical MPLAB C18 application the co18i c startup code normally specifies program memory location 0000h as the entry section and is linked into the project by the linker when specified in the MPLAB C18 linker script Since the MPLAB C18 application code in this example has been relocated to program memory address 0200h it is necessary to change the code section entry sen definition in the c018i c file as shown below and to add the co18i c source file to the project for recompiling and linking Id cO18i c v 1 1 2003 12 09 22 53 19 GrosbaJ Exp Copyright c 1999 Microchip Technology MPLAB C18 startup code including initialized data Example modification to entry section for relocation to 0200h pragma code entry scn 0x000200 void entry void _asm goto startup endasm 13 5 9 Mixed Language MPLAB C18 Application Source Code The
52. Data Sheet Errata is available from the Microchip website 316 W Register modified The working W register has been modified 317 W Register not modified BSF BCF STATUS instructions used instead The working W register has not been modified 318 Superseding current maximum ROM and ROM map Operation will cause maximum ROM to be exceeded 2005 Microchip Technology Inc DS33014J page 167 Assembler Linker Librarian User s Guide UNKNOWN MESSAGE An internal application error has occurred is the value of the last defined message plus 1 However it is not severe enough to keep your code from assembling i e itis a message not an error 8 5 ASSEMBLER LIMITATIONS 8 5 1 General Limitations There is a 62 character length restriction for file and path names in the debug COD file produced by MPASM assembler This can cause problems when assembling single files with long file names and or path names Work arounds Shorten your file name or move your file into a directory closer to the root directory shorten the path name and try assembling your file again Create a Mapped drive for the long directory chain Use the linker with the assembler and not the assembler alone to generate your output There is no character restriction with MPLINK linker If a fully qualified path is specified only that path will be searched Otherwise the search order is 1 current working directory 2 s
53. EEPROM Electrically Erasable Programmable Read Only Memory A special type of PROM that can be erased electrically Data is written or erased one byte at a time EEPROM retains its contents even when power is turned off An object file of this format contains machine code Debugging and other information is specified in with DWARF ELF DWARF provide better debugging of optimized code than COFF Emulation The process of executing software loaded into emulation memory as if it were firmware residing on a microcontroller device Emulation Memory Program memory contained within the emulator Emulator Hardware that performs emulation Emulator System The MPLAB ICE 2000 and 4000 emulator systems include the pod processor module device adapter cables and MPLAB IDE software Environment IDE The particular layout of the desktop for application development Environment MPLAB PM3 A folder containing files on how to program a device This folder can be transferred to a SD MMC card EPROM Erasable Programmable Read Only Memory A programmable read only memory that can be erased usually by exposure to ultraviolet radiation Event A description of a bus cycle which may include address data pass count external input cycle type fetch R W and time stamp Events are used to describe triggers breakpoints and interrupts Export Send data out of the MPLAB IDE in a standardized format Extended Microcontroller Mode In
54. END 0xBFF 2005 Microchip Technology Inc DS33014J page 209 Assembler Linker Librarian User s Guide DATABANK NAME gpri2 START 0xC00 END 0xCFF DATABANK NAME gpri3 START 0xD00 END 0xDFF DATABANK NAME gpri4 START 0xE00 END 0xEFF DATABANK NAME gpr15 START 0xF00 END 0xF5F ACCESSBANK NAME accesssfr START 0xF60 END 0xFFF PROTECTED SECTION NAME CONFIG ROM config SECTION NAME SRAM BASE ROM xsram STACK SIZE 0x100 RAM gpr14 13 6 4 MPLAB C18 Source Code This is a simple code example showing the use of pragma romdata for declaration of external memory and the use of C pointers for accessing this memory region include lt p18F8722 h gt pragma romdata SRAM BASE Assigns this romdata space at 0x02000 rom far char sram Declare an array at starting address Hpragma code void main void rom far char dataPtr Create a far pointer dataPtr sram Assign this pointer to the memory array dataPtr OxCC Write low byte of 16 bit word to SRAM dataPtr 0x55 Write high byte of 16 bit word to SRAM 13 6 5 Building the MPLAB C18 Application To build the MPLAB C18 sample application refer to Section 13 2 How to Build the Sample Applications The large memory model must be used in this project For MPLAB IDE at the end of Step 2 click the MPLAB C18 tab and choose the Category of Memory Model from t
55. Example data reloc label 10 constants data 1 2 ext label constants externals data testing 1 2 3 text string data N Single character data start of program relocatable label 4 15 6 PIC16 Application Example data This example shows the usefulness of directive data in storing one or more words in program memory include p16f877a inc Include standard header file for the selected device ORG 0x0000 The following code will be programmed in reset address 0 goto start Jump to an address labelled Start start Write your main program here goto Go to current line loop here ORG 0x1000 Store the string starting from 1000H Ch stng data M C U 3 program memory locations will be filled with ASCII equivalent of M C and H U gt Directive data produces three 14 bit numbers 004Dh 0043h and 0055h 4Dh 43h and 55h are ASCII equivalents of M C and U respectively tb1 dta data Oxffff 0xaa55 Places 3fffh and 2a55h in two consecutive program memory locations As program memory is 14 bit wide the last nibble can store a maximum value 3 end 2005 Microchip Technology Inc DS33014J page 63 Assembler Linker Librarian User s Guide 4 15 7 PIC18 Application Example data This example shows the usefulness of directive data in storing one or more words in program memory include p18f452 inc Include standard header file for the selected device
56. Example Program 1 Alternate output on Port B between 1 s and 0 s PRR RR RRR kkk kkk ke ke kc ke ke ce he ke he ke e ke ke ke e he ke e ke ke e e k include p16f877a inc Include header file MPLAB IDE has many header files inc available for supported devices These can be found in the installation directory See Section 5 3 3 Header Files for more on headers 2005 Microchip Technology Inc DS33014J page 125 Assembler Linker Librarian User s Guide udata Declare storage of RAM variables DTEMP res 1 Reserve 1 address location DFLAG res 1 Reserve 1 address location DFLO equ 0x00 Set flag bit 0 bit of DFLAG Set DTEMP to be a temporary register at a location in RAM determined by the linker Set DFLAG to be the flag register at a location following the DTEMP register Set DFLO to a value to represent a bit in the DFLAG register in this case 0 See the Additional Comments section for more information rst code 0x00 Reset Vector pagesel Start Ensure correct page selected goto Start Jump to Start code Place the reset vector at program memory location 0x00 When the program resets the program will branch to Start intrpt code 0x04 interrupt Vector goto ServInt Jump to service interrupt Place interrupt vector code at program memory location 0x04 since this device automatically goes to this address for interrupts When an interrupt occurs the program will branch to the ServInt routine
57. Guide This directive is not commonly used in user code as RAM and ROM details are handled by the include files inc or linker script files 1x 4 45 4 See Also badram 4 45 5 Simple Example See the examples for badram 4 46 maxrom DEFINE MAXIMUM ROM LOCATION Note maxromis preceded by two underline characters 4 46 1 Syntax _ maxrom expr 4 46 2 Description The maxromand _badrom directives together flag accesses to unimplemented registers maxrom defines the absolute maximum valid ROM address and initializes the map of valid ROM addresses to all addresses valid at and below expr expr must be greater than or equal to the maximum ROM address of the target device This directive is designed for use with the badrom directive Once the maxrom directive is used strict ROM address checking is enabled using the ROM map specified by badrom maxrom can be used more than once in a source file Each use redefines the maximum valid ROM address and resets the ROM map to all locations 4 46 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is not commonly used in user code as RAM and ROM details are handled by the include files inc or linker script files 1x 4 46 4 See Also badrom 4 46 5 Simple Example See the examples for badrom 4 47 me
58. MPLAB C18 application code can be composed of one or more relocatable C source files that are compiled and linked together during build time In the code snippet shown below the source code file uses the pragma code directive to instruct the linker to place the relocated reset and interrupt vectors at the appropriate memory locations A main function must be included as this is called from the MPLAB C18 startup code that is added during the link process DS33014J page 202 2005 Microchip Technology Inc Sample Applications include lt p18cxxx h gt VECTOR MAPPING SSA pragma code HIGH INTERRUPT VECTOR 0x000208 void high ISR void pragma code LOW INTERRUPT VECTOR 0x000218 void low ISR void APPLICATION CODE kk 4 k k k k k k k k k k k k k k k k HR RR RK KK RR kkk ke ke ke x i ISR goes here ISR goes here pragma code void main void while 1 Main application code here END OF APPLICATION Xd kk kk ok ck ck KOR RR ek oko kk FO IO IO RARA RARAS 13 5 10 Building the MPLAB C18 Application To build the MPLAB C18 sample application refer to Section 13 2 How to Build the Sample Applications 13 5 11 MPASM Assembler Usage There are three MPASM examples showing suggested linker script modifications and appropriate source code directive usage for a boot loader and application project Example 1 shows an MPASM boot loader See Section 13 5 1
59. Program registers are assigned using the udata and res directives Sections of code are created using the code statement External code is accessed using global 5 6 2 Commented Code Listing PRR RRR RRR KERR KERR ke ee ke ke he ke he ke e he ke ke Se he ke e he ke ke ce ke ke he he ke e he ke ke ce he ke e he kk kkk kkk e he ke ke e he k k k Emulates SPI in firmware Place byte in Buffer call SPI Out sends MSB first PRR RRR RRR KERR kc ke ke ec ke KK KKK RRR e he ke ke e he ke e he ke ke ke ke e he ke kkk kkk ke e he ke e kkk kkk e he ke ke e he k k k LIST P 18F4520 define processor include lt P18F4520 INC gt include file list c 132 n 0 132 col no paging AEREA RARA KK KK KK RK KKK KKK KK KK KKK KKK KKK KKK KKK KKK KR KK KK k k KK KK KK KK KKK define Clk LATB O SPI clock output define Dat LATB 1 SPI data output define Bus LATB 2 busy indicator PRR RRR RRR KKK KERR KERR KK KKK KKK e he ke KERR ke e he ke ke che ke ke e he ke kkk kkk ke e he kk he AK he ke he ke ke e he EK Variable definitions udata Buffer res 1 SPI transmit data Counter res 1 SPI transmit bit counter DelayCtr res 1 p RRR RRR RK RK RK KK KK RK RK KK KK KK KKK KKK KK KK KK KKK KK KK KKK KKK KKK KKK KK ke ke k ke k k k k k code SPI Out clrf Counter init bit counter bsf Counter 7 bcf Clk clear clock bcf Dat clear data out bsf Bus indicate busy A J
60. RVReset Re mapped RESET vector bra main R_IntH code 0x208 Re mapped HI priority interrupt vector RVIntH High priority interrupt vector code here Fe ete retfie R IntL code 0x218 Re mapped LOW priority interrupt vector RVIntL Low priority interrupt vector code here Pis te retfie user code code 0x22A main Entry into application code starts here Ao Mw ens end of main code section kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk END 13 5 16 MPASM Assembler Boot Loader Plus Application Source Code The final example demonstrates the possibility of combining both the boot loader and application code into a single program memory image that can be programmed into a target microcontroller at the same time Since the boot loader will be assembled and linked with the application source code files any references to external labels defined in the application code must be resolved by the linker To accomplish this the GLOBAL directive used in main asm and the EXTERN directive used in the boot loader source file allow the linker to resolve the relocated Reset and interrupt vector labels defined in main asm and referenced in the 18Fboot r asm Forthis example the same boot lkr linker script file used in the previous examples is used to link the boot loader and application files together 18Fboot r asm This sample version of the boot loader allows for relocatable vectors that are def
61. SRAM BASE romdata space 13 6 3 MPLAB C18 Linker Script The modified PIC18F8722 MPLAB C18 linker script file shown below demonstrates suggested modifications for external memory applications Id 18 8722 1kr v 1 2 2004 09 13 22 07 05 curtiss Exp File 18 8722 1kr Sample linker script for the PIC18F8722 processor This modified version saved as C18 xmem lkr LIBPATH FILES c018i o FILES clib lib FILES p18f8722 1ib CODEPAGE NAME vectors START 0x0 END 0x29 PROTECTED CODEPAGE NAME page START 0x2A END 0x1FFFF CODEPAGE NAME xsram START 0x020000 END 0x01FFFFF PROTECTED CODEPAGE NAME idlocs START 0x200000 END 0x200007 PROTECTED CODEPAGE NAME config START 0x300000 END 0x30000D PROTECTED CODEPAGE NAME devid START 0X3FFFFE END 0x3FFFFF PROTECTED CODEPAGE NAME eedata START 0xF00000 END 0xF003FF PROTECTED ACCESSBANK NAME accessram START 0x0 END 0x5F DATABANK NAME gpr0 START 0x60 END 0xFF DATABANK NAME gpri START 0x100 END 0x1FF DATABANK NAME gpr2 START 0x200 END 0x2FF DATABANK NAME gpr3 START 0x300 END 0x3FF DATABANK NAME gpr4 START 0x400 END 0x4FF DATABANK NAME gpr5 START 0x500 END 0x5FF DATABANK NAME gpr6 START 0x600 END 0x6FF DATABANK NAME gpr7 START 0x700 END 0x7FF DATABANK NAME gpr8 START 0x800 END 0x8FF DATABANK NAME gpr9 START 0x900 END 0X9FF DATABANK NAME gpr10 START 0xA00 END 0xAFF DATABANK NAME gpr11 START 0xB00
62. Technology Inc DS33014J page 3 CONVENTIONS USED Assembler Linker Librarian User s Guide The following conventions may appear in this documentation DOCUMENTATION CONVENTIONS Description Represents Examples Arial font Italic characters Referenced books MPLAB IDE User s Guide Emphasized text is the only compiler Initial caps A window the Output window A dialog the Settings dialog A menu selection select Enable Programmer Quotes A field name in a window or Save project before build dialog Underlined italic text with right angle bracket Bold characters Text in angle brackets gt A menu path A dialog button File gt Save Click OK A tab A key on the keyboard Click the Power tab Press Enter F1 Courier font Plain Courier Italic Courier Sample source code Hdefine START Filenames autoexec bat File paths e mec18 h Keywords asm _endasm static Command line options Opa Opa Bit values 0 1 Constants OxFF A A variable argument file o Where file can be any valid filename Square brackets Curly brackets and pipe character Optional arguments Choice of mutually exclusive arguments an OR selection mpasmwin options file options errorlevel 0 1 Ellipses Replaces repeated text var_name var name Represents code supplied by
63. WREG gt WREG 39kk ANDLW kk AND literal and W kk AND WREG gt WREG 2 0 kkk CALL kkk Call subroutine PC 1 TOS kk gt PC 0064 CLRWDT Clear Watchdog Timer 0 gt WDT and Prescaler if assigned 2 1 kkk GOTO kkk Goto address k is nine bits kk PC 9 bits 38kk IORLW kk Incl OR literal and W kk OR WREG gt WREG 30kk MOVLW kk Move Literal to W kk WREG 0062 OPTION Load OPTION register WREG gt OPTION Register 0009 RETFIE Return from Interrupt TOS gt PC 1 gt GIE 34kk RETLW kk Return with literal in W kk WREG TOS gt PC 0008 RETURN Return from subroutine TOS gt PC 0063 SLEEP Go into Standby Mode 0 WDT stop oscillator 3Ckk SUBLW kk Subtract W from literal kk WREG gt WREG 006r TRIS r Tristate port r WREG 2 I O control reg r 3Akk XORLW kk Exclusive OR literal and W kk XOR WREG gt WREG 2005 Microchip Technology Inc DS33014J page 241 Assembler Linker Librarian User s Guide A 5 12 BIT 14 BIT INSTRUCTION WIDTH PSEUDO INSTRUCTIONS The following pseudo instructions are applicable to both the 12 bit and 14 bit instruction word devices These pseudo instructions are alternative mnemonics for standard PICmicro instructions or are macros that generate one or more PlCmicro instructions Use of these pseudo instructions is not recommended for new designs These are documented mainly for historical purposes TABLE A 7 12 BIT 14 BIT SPECIAL INSTRUCTION MNEMONICS
64. WREG Commands PIC TO T2 16 MCUS iii ia iaa rh e Eo d e yer tt de past p 105 e udata Begin an Object File Uninitialized Data Section p 111 udata acs Begin an Object File Access Uninitialized Data Section PIC18 MCUS iii p 120 e udata ovr Begin an Object File Overlaid Uninitialized Data Section p 114 udata shr Begin an Object File Shared Uninitialized Data Section PIC12 16 MCUS is p 124 2005 Microchip Technology Inc DS33014J page 47 Assembler Linker Librarian User s Guide 43 access ovr BEGIN AN OBJECT FILE OVERLAY SECTION IN ACCESS RAM PIC18 MCUs 4 3 1 Syntax label access ovr RAM address 4 3 2 Description This directive declares the beginning of a section of overlay data in Access RAM If label is not specified the section is named access ovr The starting address is initialized to the specified address or will be assigned at link time if no address is specified The space declared by this section is overlaid by all other access ovr sections of the same name No code can be placed by the user in this segment 4 3 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation access ovris similar to udata acs and udata ovr except that it declares a PIC18 access RAM uninitialized data section that can be overlaid with other overlay access sections of the same name
65. a label operator and not part of the label itself 1 7 1 2 MNEMONICS DIRECTIVES AND MACROS Mnemonics tell the assembler what machine instructions to assemble For example addition add branches goto or moves movwf Unlike labels that you create yourself mnemonics are provided by the assembly language Mnemonics are not case sensitive Directives are assembler commands that appear in the source code but are not usually translated directly into opcodes They are used to control the assembler its input output and data allocation Directives are not case sensitive Macros are user defined sets of instructions and directives that will be evaluated in line with the assembler source code whenever the macro is invoked 2005 Microchip Technology Inc DS33014J page 25 Assembler Linker Librarian User s Guide Assembler instruction mnemonics directives and macro calls should begin in column two or greater If there is a label on the same line instructions must be separated from that label by a colon or by one or more spaces or tabs 1 7 1 3 OPERANDS Operands give information to the instruction on the data that should be used and the storage location for the instruction Operands must be separated from mnemonics by one or more spaces or tabs Multiple operands must be separated by commas 1 7 1 4 COMMENTS Comments are text explaining the operation of a line or lines of code The MPASM assembler treats anything
66. address above 32K was specified 134 Illegal hex file format An illegal hex file format was specified in the 1ist directive 135 Macro name missing A macro was defined without a name 136 Duplicate macro name A macro name was duplicated 137 Macros nested too deep The maximum macro nesting level was exceeded 138 Include files nested too deep The maximum include file nesting level was exceeded 139 Maximum of 100 lines inside WHILE ENDW A while endw can contain at most 100 lines 140 WHILE must terminate within 256 iterations A while endw loop must terminate within 256 iterations This is to prevent infinite assembly 141 WHILEs nested too deep The maximum while endw nesting level was exceeded 142 IFs nested too deep The maximum i nesting level was exceeded 143 Illegal nesting Macros if s and while s must be completely nested they cannot overlap If you have an if within a while loop the endif must come before the endw 144 Unmatched ENDC endc found without a cblock 145 Unmatched ENDM endm found without a macro definition DS33014J page 160 2005 Microchip Technology Inc Errors Warnings Messages and Limitations 146 Unmatched EXITM exitm found without a macro definition 147 Directive operation only allowed when generating an object file The instruction operand shown only has meaning when a linkable object file is generated It cannot be used when generating absolute code 148 Ex
67. be found in this directory This template defines a program code section named vectors which starts at address 0x0 and ends at address 0x04 Other sections are defined as well 13 3 2 Building the Application If you were to create an MPLAB IDE project with these two files and attempt to build the project see Section 13 2 How to Build the Sample Applications the result in the Output window would be as follows Note Indented lines represent a single wrapped continued line Executing C Program Files Microchip MPASM Suite MPASMWIN EXE q p16F877A f877atempo asm 1 f877atempo lst e f877atempo err o f877atempo o Executing C Program Files Microchip MPASM Suite MPLINK EXE 16f877a lkr G docs MPASM User Guide Code linker example1 f877atempo o o examplel cof MPLINK 3 90 01 Linker Copyright c 2005 Microchip Technology Inc Error section INT VECTOR can not fit the absolute section Section INT VECTOR start 0x00000004 length 0x00000018 Errors x XE BUILD FAILED Wed Feb 02 17 12 49 2005 ____ A A A a as O 2005 Microchip Technology Inc DS33014J page 193 Assembler Linker Librarian User s Guide These messages tell you that the source code assembled but the linker gave an error The linker error message is saying that a section named INT VECTOR will not fit in the memory area into which the linker is attempting to place the code The error message further says that the INT VECTOR section s
68. break here after i by n endm End of shift right macro PGM CODE This is the begining of the code section named PGM It is a relocatable code section since no absolute address is given along with directive CODE start movlw 0x88 Initialize reg hi and movwf reg hi reg lo for observation movlw 0x44 movwf reg lo shift right 3 Shift right 3 times the 16 bit data in reg hi and reg lo This is an example A value 8 will shift data 8 times goto Go to current line loop here end 2005 Microchip Technology Inc DS33014J page 121 Assembler Linker Librarian User s Guide NOTES DS33014J page 122 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 5 Assembler Examples Tips and Tricks 5 1 INTRODUCTION The usage of multiple MPASM assembler directives is shown through examples Directives are assembler commands that appear in the source code but are not opcodes They are used to control the assembler its input output and data allocation Many of the assembler directives have alternate names and formats These may exist to provide backward compatibility with previous assemblers from Microchip and to be compatible with individual programming practices If portable code is desired it is recommended that programs be written using the specifications contained within this document For a reference listing of all directives discussed in examples h
69. code see Section 1 6 Assembler Operation If you use a macro more than once and there is a label in it you will get a Duplicate Label error unless you use this directive 4 43 4 See Also endm macro 4 43 5 Simple Example main code segment gt len equ 10 global version size equ 20 note that a local variable may now be created and modified test macro size local len label local len and label len set size modify local len label res len reserve buffer len set len 20 endm end macro DS33014J page 94 2005 Microchip Technology Inc Directives 4 43 6 Application Example local This code demonstrates the utility of Local directive which declares that the specified data elements are to be considered in local context to the macro include p16f877a inc Include standard header file for the selected device incr equ 2 Assembler variable incr is set equal to 2 add incr macro Declaration of macro add incr local incr Local assembler variable incr The same name incr is used in the main code where its value is set to 2 incr set 3 Local incr is set to 3 in contrast to incr value of 2 in main code clrw w register is set to zero addlw incr w register is added to incr and result placed back endm in w register RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST
70. command line This version is available with the regular and demo version of the MPLAB C18 C compiler The MPASM assembler supports all PlCmicro MCU devices as well as memory and KeeLoq secure data products from Microchip Technology Inc Some memory and KeeLoq devices were not supported in MPLAB IDE after v5 70 40 1 3 HOW MPASM ASSEMBLER HELPS YOU The MPASM assembler provides a universal solution for developing assembly code for all of Microchip s PICmicro MCUs Notable features include MPLAB IDE Compatibility Command Line Interface Windows Command Shell Interfaces Rich Directive Language Flexible Macro Language 2005 Microchip Technology Inc DS33014J page 21 Assembler Linker Librarian User s Guide 1 4 ASSEMBLER MIGRATION PATH Since the MPASM assembler is a universal assembler for all PICmicro MCU devices application code developed for the PIC16F877A can be translated into a program for the PIC18F452 This may require changing the instruction mnemonics that are not the same between the devices assuming that register and peripheral usage were similar The rest of the directive and macro language will be the same 1 5 ASSEMBLER COMPATIBILITY ISSUES The MPASM assembler is compatible with the MPLAB IDE integrated development environment mpasmwin exe version and all Microchip PICmicro MCU development systems currently in production The MPASM assembler supports a clean and consistent method of specif
71. compiler MPLAB LINK30 MPLAB LINK30 is an object linker for the Microchip MPLAB ASM30 assembler and the Microchip MPLAB C30 C compiler MPLAB PM3 A device programmer from Microchip Programs PIC18 microcontrollers and dsPIC digital signal controllers Can be used with MPLAB IDE or stand alone Will obsolete PRO MATE Il MPLAB SIM Microchip s simulator that works with MPLAB IDE in support of PICmicro MCU and dsPIC DSC devices MPLIB Object Librarian MPLIB librarian is an object librarian for use with COFF object modules created using either MPASM assembler mpasm or mpasmwin v2 0 or MPLAB C1X C compilers 2005 Microchip Technology Inc DS33014J page 257 Assembler Linker Librarian User s Guide MPLINK Object Linker MPLINK linker is an object linker for the Microchip MPASM assembler and the Microchip MPLAB C17 or C18 C compilers MPLINK linker also may be used with the Microchip MPLIB librarian MPLINK linker is designed to be used with MPLAB IDE though it does not have to be MRU Most Recently Used Refers to files and windows available to be selected from MPLAB IDE main pull down menus Nesting Depth The maximum level to which macros can include other macros Node MPLAB IDE project component Non Real Time Refers to the processor at a breakpoint or executing single step instructions or MPLAB IDE being run in simulator mode Non Volatile Storage A storage device whose contents are preserved when it
72. data memory ch tbl2 de PICwithFLASH 12 EE data memory locations starting from 0 will be filled with 12 ASCII characters end 4 50 7 PIC18 Application Example org This example shows the usage of the org directive Code generation begins at an address specified by org address The origin of a data table also can be specified by this directive A data table may be placed either in a program memory region or in an EE data memory region as in case of a PICmicro device with EE data Flash include p18f452 inc Include standard header file for the selected device org 0x0000 The following code will be programmed in reset address 0 goto Main Jump to an address whose label is Main org 0x0008 The following code will be programmed in high priority interrupt address 8 goto int hi Jump to an address whose label is int hr org 0x0018 The following code will be programmed in low priority interrupt address 18h goto int lo Jump to an address whose label is pLint Tot org 0x0020 The following code section will be programmed starting from address 20H Main A Write your main program here goto Main Loop back to Main org 0x0100 The following code section will be programmed starting from address 100H int hi DS33014J page 102 2005 Microchip Technology Inc Directives e Write your high priority interrupt service routine here retfie Return from interrupt
73. executables can be found The path to MPLAB C18 is only needed if this tool is to be used Executables Default Path to Executables mcci8 exe c mcci8 bin mpasmwin exe c mcci8 mpasm or c program files microchip mpasm suite mplink exe c mcci8 bin or c program files microchip mpasm suite MCC INCLUDE This should point to c mec18 h default path if MPLAB C18 is to be used 2 For MPLAB C18 compilation use the following mcc18 p device sourcel c where device is the selected sample application device and source1 c is the C code source file example For multiple files leave a space between each file 3 For MPASM assembly use the following mpasmwin p device source2 asm where device is the selected sample application device and source2 asmis the assembly code source file example For multiple files leave a space between each file 4 To link the files and create the application use MPLINK linker as follows mplink script lkr sourcel o source2 o l c mcc18 lib m app map where script 1kris the linker script file souzce1 ois the C code object file source2 oisthe assembly code object file and app map is the map file The library path c mcc18 1ib is only needed if MPLAB C18 was used as here to generate source1 o from source1 c A a M n AAA AAA AA DS33014J page 192 O 2005 Microchip Technology Inc Sample Applications 13 3 SAMPLE APPLICATION 1 MODIFYING THE LINKER SCRIP
74. expanded examples of use In most cases simple examples may be assembled and run by adding an ena statement Expanded examples may be assembled and run as is to give an demonstration of an application using the directive s Individual directives may be found alphabetically in the following sections or by type Section 4 2 Directives by Type Note Directives are not case sensitive e g colock may be executed as CBLOCK cblock Cblock etc 4 2 DIRECTIVES BY TYPE There are six basic types of directives provided by the assembler Control Directives Conditional Assembly Directives Data Directives Listing Directives Macro Directives Object File Directives DP UN O 2005 Microchip Technology Inc DS33014J page 45 Assembler Linker Librarian User s Guide 4 2 1 Control Directives Control directives control how code is assembled e define Define a Text Substitution Label p 68 e include Include Additional Source File sseessssss p 92 e undefine Delete a Substitution Label p 117 e constant Declare Symbol Constant p 60 end End Program BIock 2 tede e ted p 71 e equ Define an Assembler Constant p 74 org Set Program Origin p 100 e processor Set Processor Type ooooocconccccnocncnncnnnconccconncnnanncnnnnnnnnna cnn p 106 e radix Specify Default Radix oooooocnnnncnncccincccnnnocnnnnnccnonannnnnnnccnnrna nana ncnnnns p 106 e
75. he ke e he ke kkk ke e he ke e kkk kkk e ke ke ke e he k k k global Hex2ASC ASCIIH ASCIIL END 5 8 OTHER SOURCES OF EXAMPLES Short examples of use for each directive are listed under each directive topic See Chapter 4 Directives Examples of use for multiple directives are available from the following sources readme asm Serial EEPROM Support Application Notes Technical Briefs Website http www microchip com Code Examples and Templates MPLAB IDE installation directory Website http www microchip com 5 9 TIPS AND TRICKS To reduce costs designers need to make the most of the available program memory in MCUs Program memory is typically a large portion of the MCU cost Optimizing the code helps to avoid buying more memory than needed Here are some ideas that can help reduce code size For more information see Tips n Tricks DS40040 TIP 1 Delay Techniques TIP 2 Optimizing Destinations TIP 3 Conditional Bit Set Clear TIP 4 Swap File Register with W TIP 5 Bit Shifting Using Carry Bit 5 9 1 TIP 1 Delay Techniques Use GOTO Next Instruction instead of two NOPs Use CALL Rtrn as quad 1 instruction NOP where Rtrn is the exit label from existing subroutine PRR RRR RRR KERR kc ke ke ee ke k k kkk he ke k k k k k he ke e ke kk k k k k he k e ke k e e e k NOP NOP 2 instructions 2 cycles PRR RRR RR cech kc ke ke ee ke kk kkk he ke k ke ke k k he ke e ke ke
76. in code section RST goto start Jumps to the location labelled start PGM CODE This is the begining of the code section named PGM It is a relocatable code section Since no absolute address is given along with directive CODE start clrf groupl varl1 A groupl varl initialized to zero clrf groupl var2 A groupl var2 initialized to zero clrf group2 varl A group2 varl initialized to zero clrf group2 var2 A group2 var2 initialized to zero goto Go to current line loop here end In the code above A references the access RAM This A designation can be explicitly stated by the code but is not needed since the assembler will automatically locate variables in access memory if possible 4 63 udata ovr BEGIN AN OBJECT FILE OVERLAID UNINITIALIZED DATA SECTION 4 63 1 Syntax 1abel udata ovr RAM address 4 63 2 Description This directive declares the beginning of a section of overlaid uninitialized data If 1abe1 is not specified the section is named udata ovr The starting address is initialized to the specified address or will be assigned at link time if no address is specified The space declared by this section is overlaid by all other udata ovr sections of the same name It is an ideal way of declaring temporary variables since it allows multiple variables to be declared at the same memory location No code can be generated in this segment The res directive should be used to reserve space for data Note
77. in the idata section the variables will be initialized with O include p16f877a inc Include standard header file for the selected device 2005 Microchip Technology Inc DS33014J page 85 Assembler Linker Librarian User s Guide groupl IDATA 0x20 Initialized data at location 20h groupl varl res 1 groupl varl located at 0x20 initialized with 0 groupl var2 res 1 groupl var2 located at 0x21 initialized with 0 group2 IDATA Declaration of group2 data The addresses for variables under this data section are allocated automatically by the linker group2 varl db 1 2 3 4 4 bytes in RAM are reserved group2 var2 dw 0x1234 1 word in RAM is reserved RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start U Start PGM CODE This is the begining of the code section named PGM It is a relocatable code section Since no absolute address is given along with directive CODE start goto Go to current line loop here end 4 36 idata acs BEGIN AN OBJECT FILE INITIALIZED DATA SECTION IN ACCESS RAM PIC18 MCUs 4 36 1 Syntax label idata acs RAM address 4 36 2 Description This directive declares the beginning of a section of initialized data in Access RAM If label is not specified the section is named idata_acs The starting address is
78. k kk kk k kkk k kkk k GOTO 41 1 instruction 2 cycles ARA cec ke kc ke ke ce ke Sk ce he ke he ke e ke ke ke e he ke e kkk kk kkk ke e ke k kkk k Call Rtrn 1 instruction 4 cycles Rtrn RETURN PRR RRR RRR kkk kkk kkk kk he ke he ke e ke ke kk he ke e kkk kkk kkk kkk kkk k MCUS are commonly used to interface with the outside world by means of a data bus LED s buttons latches etc Because the MCU runs at a fixed frequency it will often need delay routines to meet setup hold times of other devices pause for a handshake or decrease the data rate for a shared bus 2005 Microchip Technology Inc DS33014J page 139 Assembler Linker Librarian User s Guide Longer delays are well suited for the DECFSZ and INCFSZ instructions where a variable is decremented or incremented until it reaches zero when a conditional jump is executed For shorter delays of a few cycles here a few ideas to decrease code size For atwo cycle delay itis common to use two NOP instructions which uses two program memory locations The same result can be achieved by using GOTO 1 The represents the current program counter value in MPASM assembler When this instruction is encountered the MCU will jump to the next memory location This is what it would have done if two NOP s were used but since the GOTO instruction uses two instruction cycles to execute a two cycle delay was created This created a two cycle delay using only one location of pro
79. located at 0x121 tion named RST program memory The next two are placed in RST location labelled This is the begining of the code section a relocatabl named PGM It is e code section Since no absolute address is given along with directive CODE This part of the code addresses variables groupl varl amp groupl var2 Go to current line indirectly loop here 2005 Microchip Technology Inc DS33014J page 51 Assembler Linker Librarian User s Guide 4 7 4 6 7 Application Example 2 bankisel include p16f877a inc Include standard header file for the selected device bankisel EEADR This register is at location 100h in banks 2 or 3 so the IRP bit must be set bankisel will set it but only where it is used movlw EEADR W Put the address of the register to be accessed indirectly into W movwt FSR Copy address from W to FSR to set up pointer to EEADR clrf INDF Clear EEADR through indirect accessing of EEADR through FSR INDF It would have cleared PIR2 00Dh if backisel had not been used to set the IRP bit goto Prevents fall off end of code end All code must have an end statement banksel GENERATE BANK SELECTING CODE 4 7 1 Syntax banksel label 4 7 2 Description This directive is an instruction to the assembler and linker to generate bank selecting code to set the bank to the bank containing the designated 14be1 Only one labe
80. macro may be comprised of MPASM assembler directives PICmicro MCU assembly instructions or MPASM assembler macro directives 1ocal for example The assembler continues to process the body of the macro until an exitm or endm directive is encountered Note Macros must be defined before they are used i e forward references to macros are not permitted 2005 Microchip Technology Inc DS33014J page 153 Assembler Linker Librarian User s Guide 7 3 MACRO DIRECTIVES DEFINED There are directives that are unique to macro definitions They cannot be used out of the macro context 4 44 macro Declare Macro Definition 4 30 exitm Exit from a Macro 4 25 endm End a Macro Definition 4 31 expand Expand Macro Listing 4 48 noexpand Turn off Macro Expansion 4 43 local Declare Local Macro Variable When writing macros you can use any of these directives PLUS any other directives supported by the assembler Note The previous syntax of the dot format for macro specific directives is no longer supported 7 4 MACRO DEFINITION String replacement and expression evaluation may appear within the body of a macro Command Description arg Substitute the argument text supplied as part of the macro invocation v expr Return the integer value of expr Typically used to create unique variable names with common prefixes or suffixes Cannot be used in conditional assembly directiv
81. name If the name is not specified it will be given the default name code Each program memory section must be contiguous within a single source file A section may not be broken into pieces within a single source file The physical address of the code can be fixed by supplying the optional address parameter of the code directive Situations where this might be necessary are Specifying reset and interrupt vectors Ensuring that a code segment does not overlap page boundaries EXAMPLE 6 2 RELOCATABLE CODE Reset code Ox01FF Fixed address goto Start Main code Address determined by the linker clrw option 6 4 LOW HIGH AND UPPER OPERANDS Low high and upper operands are used to return one byte of a multi byte label value If low is used only bits O through 7 of the expression will be used If high is used only bits 8 through 15 of the expression will be used If upper is used only bits 16 through 21 of the expression will be used Operand Definition low Return low byte of address high Return high byte of address upper Return upper byte of address scnsz low Return low byte of section size scnsz high Return high byte of section size scnsz upper Return upper byte of section size scnend low Return low byte of section end address scnend high Return high byte of section end address scnend upper Return upper byte of section end address scnstart low Return low byte of section start address scnst
82. named udata The starting address is initialized to the specified address or will be assigned at link time if no address is specified No code can be generated in this segment The res directive should be used to reserve space for data Note Two sections in the same source file are not permitted to have the same name 4 61 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation 2005 Microchip Technology Inc DS33014J page 111 Assembler Linker Librarian User s Guide For relocatable code this directive is used to create a data RAM section For absolute code do not use this directive Use directives equ or cblock 4 61 4 See Also extern global idata udata acs udata ovr udata shr 4 61 5 Simple Example udata Vari res 1 Double res 2 4 61 6 Application Example udata This program demonstrates the udata directive which declares the beginning of a section of uninitialized data udata does not set initialize the starting value of the variables you must do this in code include p16f877a inc Include standard header file for the selected device groupl udata 0x20 groupl data stored at locations starting at 0x20 groupl varl res 1 groupl varl located at 0x20 groupl var2 res 1 groupl var2 located at 0x21 group2 udata Declaration of group2 data The addresses for variables under group2 varl res 1 this
83. pagesel start Jumps to the location labelled goto start start PGM CODE This is the begining of the code section named PGM It is a relocatable code section since no absolute address is given along with directive CODE start clrw W register set to zero addlw incr W register is added with the value of incr which is now equal FEO 2 add_incr W register is added with the value of incr which is now equal to 3 value set locally in the macro add incr clrw W register is set to zero again addlw incr incr is added to W register and result placed in W register incr value is again 2 not affected by the value set in the macro goto Go to current line loop here end 2005 Microchip Technology Inc DS33014J page 95 Assembler Linker Librarian User s Guide 4 44 macro DECLARE MACRO DEFINITION 4 44 44 Syntax label macro arg arg 4 44 2 Description A macro is a sequence of instructions that can be inserted in the assembly source code by using a single macro call The macro must first be defined then it can be referred to in subsequent source code Arguments are read in from the source line stored in a linked list and then counted The maximum number of arguments would be the number of arguments that would fit on the source line after the label and macro terms Therefore the maximum source line length is 200 characters A macro can call another macro or may call itself r
84. pos W addwf TBLPTRL F clrf WREG addwfc TBLPTRH F addwfc TBLPTRU F stan next char 1 tblrd Ry movff TABLAT temp wr call d write send character to LCD decfsz ptr count F move pointer to next char bra stan next char 1 movlw n move data into TXREG movwf TXREG next line btfss TXSTA TRMT wait for data TX goto 2 movlw Np move data into TXREG movwf TXREG carriage return btfss TXSTA TRMT wait for data TX goto 2 return DS33014J page 146 2005 Microchip Technology Inc Relocatable Objects 6 5 RAM ALLOCATION RAM space must be allocated in a data section Five types of data sections are available Note The ability to use access overlaid or shared data varies by device Consult your device data sheet for more information udata Uninitialized data This is the most common type of data section Locations reserved in this section are not initialized and can be accessed only by the labels defined in this section or by indirect accesses See 4 61 udata Begin an Object File Uninitialized Data Section udata acs Uninitialized access data This data section is used for variables that will be placed in access RAM of PIC18 devices Access RAM is used as quick data access for specified instructions See 4 62 udata acs Begin an Object File Access Uninitialized Data Section PIC18 MCUs udata ovr Uninitialized overlaid data This data section is u
85. reassigned a value o and wdth will be removed from the symbol list in the list 1st file The label Lngth must be undefined before it can be defined as o 2005 Microchip Technology Inc DS33014J page 69 Assembler Linker Librarian User s Guide 4 19 at DEFINE TABLE PIC12 16 MCUs 4 19 1 Syntax 1abel dt expr expr expr 4 19 2 Description dt Data Table Generates a series of RETLW instructions one instruction for each expr Each expr must be an 8 bit value Each character in a string is stored in its own RETLW instruction 4 193 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is used when generating a table of data for the PIC12 16 device family If you are using a PIC18 device it is recommended that you use the table read write TBLRD TBLWT features See the device data sheet for more information 4 19 4 See Also data db de dw 4 19 5 Simple Example dt A Message 0 dt FirstValue SecondValue EndOfValues 4 20 dw DECLARE DATA OF ONE WORD 4 20 4 Syntax label dw expr expr expr 4 20 2 Description dw Data Word Reserve program memory words for data initializing that space to specific values For PIC18 devices dw functions like db Values are stored into successive memory locations and the location counter is incremented by one
86. set Define an Assembler Variable ssseeeeeeee p 109 e variable Declare Symbol Variable p 118 4 2 2 Conditional Assembly Directives Conditional assembly directives permit sections of conditionally assembled code These are not run time instructions like their C language counterparts They define which code is assembled not how the code executes e else Begin Alternative Assembly Block to if Conditional p 71 e endif End Conditional Assembly Block p 72 lt endw End a while L00p utere bee iere ett p 73 e if Begin Conditionally Assembled Code Block p 88 e ifdef Execute If Symbol has Been Defined p 90 e ifndef Execute If Symbol has not Been Defined p 91 e while Perform Loop While Condition is True p 119 4 2 3 Data Directives Data directives control the allocation of memory and provide a way to refer to data items symbolically i e by meaningful names badram Identify Unimplemented RAM p 48 badrom Identify Unimplemented ROM p 49 config Set Processor Configuration Bits sssssssss p 58 config Set Processor Configuration Bits PIC18 MCUXS p 59 idlocs Set Processor ID Locations p 87 maxram Define Maximum RAM Location
87. single output section The linker allocation algorithm is described in Section 12 3 Linker Allocation Algorithm Once the linker has allocated all sections from all input modules into target memory it begins the process of symbol relocation The symbols defined in each input section have addresses dependent upon the beginning of their sections The linker adjusts the symbol addresses based upon the ultimate location of their allocated sections After the linker has relocated the symbols defined in each input section it resolves external symbols The linker attempts to match all external symbol references with a corresponding symbol definition If any external symbol references do not have a corresponding symbol definition an attempt is made to locate the corresponding symbol definition in the input library files If the corresponding symbol definition is not found an error is generated If the resolution of external symbols was successful the linker then proceeds to patch each section s raw data Each section contains a list of relocation entries which associate locations in a section s raw data with relocatable symbols The addresses of the relocatable symbols are patched into the raw data The process of relocating symbols and patching section is described in Section 12 4 Relocation Example After the linker has processed all relocation entries it generates the executable output module 2005 Microchip Technology Inc DS33014J pag
88. the following data to be placed only in the data area perimeter res 2 Two locations of memory are reserved for the label perimeter Addresses of the memory locations will be allocated by the linker length res 1 One location of memory is reserved for the label length Address of the memory location will be allocated by the linker width res 1 One location of memory is reserved for the label width Address of the memory location will be allocated by the linker Start CODE 0x0000 Following code will be placed in address 0 Here the directive code has the same effect as org But org is used with MPASM assembler to generate absolute code and code is used with MPLINK linker to generate an object file code is also different in that an address is not normally specified the linker handles the allocation of space both in program Flash and data RAM memory goto PER CAL Jump to label PER_CAL CODE CODE directive here dictates that the following lines of code will be placed in program memory but the starting address will be decided by the linker PER CAL clrf perimeter 1 Clear the high byte of the label perimeter movf length w Move the data present in the register addressed by length to w addwf width w Add data in w with data in the register addressed by width H UX X X
89. the MPASM assembler and the MPLINK linker can generate a hex file For more information on this format see Section 1 7 5 Hex File Formats hex hxl hxh For MPLINK linker MP2HEX EXE uses the COFF file to generate the hex file To prevent hex file generation use the x option 9 7 7 Listing File Ist An MPLINK linker listing file provides a mapping of source code to object code It also provides a list of symbol values memory usage information and the number of errors warnings and messages generated This file may be viewed in MPLAB IDE by 1 Selecting File gt Open to launch the Open dialog Selecting List files Ist from the Files of type drop down list Locating the desired list file Clicking on the list file name Clicking Open Qr E ON DS33014J page 174 2005 Microchip Technology Inc MPLINK Linker Overview MP2COD 3 80 03 Both the MPASM assembler and the MPLINK linker can generate listing files For information on the MPASM assembler listing file see Section 1 7 3 Listing File Ist An alternative to a listing file would be to use the information in the Disassembly window View gt Disassembly in MPLAB IDE For MPLINK linker MP2COD EXE uses the COFF file to generate the COD and list files To prevent COD and linker list file generation use the w option EXAMPLE 9 1 MPLINK LINKER LISTING FILE The COFF to COD file converter version and list file generation data appear at t
90. the symbols in the output module The table is sorted by the symbol name and includes the address of the symbol whether the symbol resides in program or data memory whether the symbol has external or static linkage and the name of the file where defined The following table is an example of the symbol table sorted by symbol name in a map file Symbols Sorted by Name Name Address Location Storage File call m 0x000026 program Static C PROGRA 1 MPLAB ASMFOO sampob asm loop 0x00002e program static C MPASM assemblerV2 MUL8X8 ASM main 0x000024 program static C PROGRA 1 MPLAB ASMFOO sampobj asm mpy 0x000028 program extern C MPASM assemblerV2 MUL8X8 ASM start 0x000023 program static C PROGRA 1 MPLAB ASMFOO sampob asm H byte 0x000022 data extern C MPASM assemblerV2 MUL8X8 ASM L byte 0x000023 data extern C MPASM assemblerV2 MUL8X8 ASM count 0x000024 data static C MPASM assemblerV2 MUL8X8 ASM mulcnd 0x000020 data extern C MPASM assemblerV2 MUL8X8 ASM mulplr 0x000021 data extern C MPASM assemblerV2 MUL8X8 ASM DS33014J page 176 2005 Microchip Technology Inc MPLINK Linker Overview The fourth table in the map file Symbols Sorted by Address provides the same information that the second table provides but it is sorted by symbol address rather than symbol name If a linker error is generated a complete map file can not be created However if the m option was supplied an error map file wi
91. the while directive and the endw directive will be repeatedly expanded in the assembly source code stream This directive may be used inside a regular program block or macro 2005 Microchip Technology Inc DS33014J page 73 Assembler Linker Librarian User s Guide 4 26 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation For every while directive used there must be a corresponding endw while and endw are not instructions but used for code assembly only 4 26 4 See Also while 4 26 5 Examples See the example under while 4 27 equ DEFINE AN ASSEMBLER CONSTANT 4 27 4 Syntax label equ expr 4 27 2 Description The value of expr is assigned to label 4 27 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation In a single assembly file program equ is commonly used to assign a variable name to an address location in RAM Do not use this method for assigning variables when building a linked project use a res directive inside a data section directive idata udata 4 27 4 See Also set cblock res idata udata udata acs udata ovr udata shr 4 27 5 Simple Example four equ 4 assigned the numeric value of 4 to label four 4 27 6 Application Example set equ See this example under set 4 28 error ISSU
92. them You may wish to reconfigure stack size to use MPLAB C18 with MPLINK linker You will need to split up memory pages if your code contains goto or call instructions without pagesel pseudo instructions directives You must not combine data memory regions when using MPLINK linker with MPLAB C18 C compiler MPLAB C18 requires that any section be located within a single bank See MPLAB C18 documentation for directions on creating variables larger then a single bank 11 5 MEMORY REGION DEFINITION The linker script describes the memory architecture of the PlCmicro MCU This allows the linker to place code in available ROM space and variables in available RAM space Regions that are marked PROTECTED will not be used for general allocation of program or data Code or data will only be allocated into these regions if an absolute address is specified for the section or if the section is assigned to the region using a SECTION directive in the linker script file 11 5 1 Defining RAM Memory Regions The DATABANK SHAREBANK and ACCESSBANK directives are used for variable data in internal RAM The formats for these directives are as follows Banked Registers DATABANK NAME memName START addr END addr PROTECTED Unbanked Registers SHAREBANK NAME memName START addr END addr PROTECTED Access Registers PIC18 devices only ACCESSBANK NAME memName START addr END addr PROTECTED where memName is any ASCII str
93. to the library object directory search path are appended to the end of the current library object directory search path as they are encountered on the command line and in command files Library and object files are searched for in the order in which directories occur in the library object directory search path Therefore changing the order of directories may change which file is selected The o option is used to supply the name of the generated output COFF file for MPLAB IDE debugging Also generated is an Intel format hex file for programming This file has the same name as the output COFF file but with the file extension hex If the o option is not supplied the default output COFF file is named a out and the corresponding hex file is named a hex 10 4 COMMAND LINE EXAMPLE An example of an MPLINK linker command line is shown below mplink 18f 452 1kr main o funct o math lib m main map o main out This instructs MPLINK linker to use the 18 452 1kr linker script file to link the input modules main o funct o and the precompiled library math 1ipb It also instructs the linker to produce a map file named main map main o and funct o must have been previously compiled or assembled The output files main cof and main hex will be produced if no errors occur during the link process DS33014J page 180 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 11 Linker Scripts 11 1 INT
94. types of code relocatable For information on types of code see Section 1 6 Assembler Operation This directive is similar to udata except that it is used only for PIC18 devices and will only place variables in access RAM PIC18 devices have an area of RAM known as access RAM Variables in access memory can be used no matter where the bank select register BSR is pointing It is very useful for frequently used and global variables 4 62 4 See Also extern global idata udata udata ovr udata shr 4 62 5 Simple Example udata acs Varl res 1 Double res 2 4 62 6 Application Example udata acs This program demonstrates the udata_acs directive This directive declares the beginning of a section of uninitialized data include p18f452 inc Include standard header file for the selected device group1 udata acs 0x20 groupl data stored at access RAM locations starting at 0x20 groupl varl res 1 groupl varl located at 0x20 groupl var2 res 1 groupl var2 located at 0x21 group2 udata acs Declaration of group2 data The addresses for data under this secton are allocated automatically by the linker group2 varl res 1 All addresses be will allocated group2 var2 res 1 in access RAM space only RST CODE 0x0 The code section named RST is placed at program memory 2005 Microchip Technology Inc DS33014J page 113 Assembler Linker Librarian User s Guide location 0x0 The instruction goto start is placed
95. way of grouping related object modules A library file may be created from object files by MPLIB librarian For more on the librarian see Chapter 15 MPLIB Librarian Overview 9 7 3 Linker Script File Ikr Linker script files are the command files of MPLINK linker For more information on linker scripts see Chapter 11 Linker Scripts Standard linker script files are located in C Program Files Microchip MPASM Suite LKR During the link process if MPLINK linker is unable to resolve a reference to a symbol it will search libraries specified on the command line or in the linker script in an attempt to resolve the reference If a definition is found in a library file the object file containing that definition will be included in the link 9 7 4 COFF Object Module File cof out MPLINK linker generates a COFF file which provides debugging information to MPLAB IDE v6 xx or later MP2COD EXE generates the COD files and list files from the COFF file and MP2HEX EXE generates the hex file 9 7 5 Symbol and Debug File cod Both the MPASM assembler and the MPLINK linker can generate a COD file for use with MPLAB IDE v5 xx and earlier For more information on this format see Section 1 7 7 Symbol and Debug File cod For MPLINK linker MP2COD EXE uses the COFF file to generate the COD and list files To prevent COD and linker list file generation use the w option 9 7 6 Hex File Formats hex hxl hxh Both
96. where they are defined This allows a project to be split up into multiple files two in this example for code reuse PRR RR RRE RRE EEK kkk EEK k kk kk k k k he ke e k he k k he k k he ke e k ke e e he ke e ke k ke e k main asm PRR RRR RRR ck ke kc e ke ke ce ke ke he ke he ke e he ke ke e kkk kk ke he ke kkk ke e ke k kkk ke e ke k ke e k Hinclude p16f877a inc Include standard header file for the selected device UDATA delay value res 1 GLOBAL delay value The variable delay value declared GLOBAL in this module is included in an EXTERN directive in the module Sub asm EXTERN delay The variable delay declared EXTERN in this module is declared GLOBAL in the module Sub asm RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start start PGM CODE This is the begining of the code section named PGM It is a relocatable code section Since no absolute address is given along with directive CODE start moviw D 10 movwf delay value xorlw 0x80 call delay goto start end PRR RRR check ce ke cec ke ke ee ke ke e he ke he ke e ke ke ke e he ke e ke ke ke ke kkk ke e ke ke kkk ke e ke k ke kk sub asm PRR RRR RRR KKK kc e ke ke EEE KE EEE he ke e ke ke kkk kkk he ke he kkk ke e ke k kkk ke e ke k e e k Hinclude p16f877a inc Include standard header
97. will be loaded into external RAM and executed Sample Application 4 explains how to create a new linker script memory section how to declare external memory through pragma code directive and how to access external memories using C pointers Chapter 14 Errors Warnings and Common Problems contains a descriptive list of the errors and warnings generated by the MPLINK linker as well as common problems and tool limitations DS33014J page 2 2005 Microchip Technology Inc Preface MPLIB Object Librarian Chapter 15 MPLIB Librarian Overview describes what the MPLIB object librarian is what it does and how it works with other tools Chapter 16 Librarian Interfaces reviews how to use the MPLIB librarian with MPLAB IDE and describes how to use the librarian on the command line Chapter 17 Errors contains a descriptive list of the errors generated by the MPLIB librarian Appendices Appendix A Instruction Sets lists PICmicro MCU device instruction sets Appendix B Useful Tables provides some useful tables for code development ASCII Character Set lists the ASCII Character Set Hexadecimal to Decimal Conversions shows how to convert from hexadecimal to decimal numbers A a A A P M MR 2005 Microchip
98. will be no exit from the recursion ROM Read Only Memory Program Memory Memory that cannot be modified Run The command that releases the emulator from halt allowing it to run the application code and change or respond to I O in real time Scenario For MPLAB SIM simulator a particular setup for stimulus control SFR See Special Function Registers Shell The MPASM assembler shell is a prompted input interface to the macro assembler There are two MPASM assembler shells one for the DOS version and one for the Windows version Simulator A software program that models the operation of devices Single Step This command steps though code one instruction at a time After each instruction MPLAB IDE updates register windows watch variables and status displays so you can analyze and debug instruction execution You can also single step C compiler source code but instead of executing single instructions MPLAB IDE will execute all assembly level instructions generated by the line of the high level C statement Skew The information associated with the execution of an instruction appears on the proces Sor bus at different times For example the executed Opcodes appears on the bus as a fetch during the execution of the previous instruction the source data address and value and the destination data address appear when the Opcodes is actually executed and the destination data value appears when the next instruction is executed T
99. you may have a right to sue for relief under that Act Information contained in this publication regarding device applications and the like is provided only for your convenience and may be superseded by updates It is your responsibility to ensure that your application meets with your specifications MICROCHIP MAKES NO REPRESENTATIONS OR WAR RANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED WRITTEN OR ORAL STATUTORY OR OTHERWISE RELATED TO THE INFORMATION INCLUDING BUT NOT LIMITED TO ITS CONDITION QUALITY PERFORMANCE MERCHANTABILITY OR FITNESS FOR PURPOSE Microchip disclaims all liability arising from this information and its use Use of Microchip s products as critical components in life support systems is not authorized except with express written approval by Microchip No licenses are conveyed implicitly or otherwise under any Microchip intellectual property rights QUALITY MANAGEMENT SYSTEM CERTIFIED BY DNV ISO TS 16949 2002 Trademarks The Microchip name and logo the Microchip logo Accuron dsPIC KEELOQ microID MPLAB PIC PICmicro PICSTART PRO MATE PowerSmart rfPIC and SmartShunt are registered trademarks of Microchip Technology Incorporated in the U S A and other countries AmpLab FilterLab Migratable Memory MXDEV MXLAB PICMASTER SEEVAL SmartSensor and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U S A Analog for the Digital Age
100. 0 groupl var2 res 1 groupl var2 located at 0x21 group2 udata 0xAO0 group2 data stored at locations starting at OxAO bank 1 group2 varl res 1 group2 var2 res 1 RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start A RSEALE A PGM CODE This is the begining of the code section named PGM It is a relocatable code section since no absolute address is given along with directive CODE start banksel groupl vari This directive generates code to set clear bank select bits RPO RP1 of STATUS register depending upon the address of groupl vari clrf groupl varl clrf groupl var2 banksel group2 vari This directive generates code to set clear bank select bits RPO amp RP1 of STATUS register depending upon the address of group2 varl clrf group2 varl clrf group2 var2 goto Go to current line loop here end ____ MA lt A r 2005 Microchip Technology Inc DS33014J page 53 Assembler Linker Librarian User s Guide 4 8 4 7 7 Application Example 2 banksel include p16f877a inc Include standard header file for the selected device banksel TRISB Sin
101. 000 0x000029 vector Reset Interrupts Vectors IntH IntL 0x00002A 0x0001FF boot code Boot Loader Boot 0x000200 0x000229 r vectors Remapped Vectors R vectors R_IntH R_IntL 0x00022A user code User Code Ox1 EFFFF 7 user_code Boot Loader Updated 0x1F0000 Application Code Ox1 FFFEF const Data Tables 13 5 13 MPASM Assembler Linker Script To protect the boot block and vector memory regions the linker script file uses modified CODEPAGE directives to establish these memory regions and uses the PROTECTED modifier to prevent the linker from assigning any relocatable code that is not explicitly assigned to these regions The sample linker script below shows how the linker can assign the relocatable application code to the user code memory region that is not protected The other program memory regions can only be populated if the CODE directive used in the source files specifies placement of code within these protected memory regions This linker script file is designed to accommodate all three boot loader design considerations demonstrated in this chapter boot Ikr The linker script file for boot loader and application code example projects Id 18 8720 1lkr v 1 8 2004 06 18 19 46 16 ConnerJ Exp File 18 8720 1kr Sample linker script for the PIC18F8720 processor Modified 2005 02 02 for MPASM boot loader examples LIBPAT
102. 014J page 15 Assembler Linker Librarian User s Guide Build the Project Select Project gt Build All to build the project Note You also may right click on the project name Example mcp in the project tree and select Build All from the pop up menu The Output window should appear at the end of the build and display the build results FIGURE 4 OUTPUT WINDOW BUILD TAB Clean Deleting intermediary and output files Clean Done Executing CAProgram Files MPLAB IDE MCHIP_Tools mpasmwin exe q plbF84A Example asm l Example Ist e E Executing C Program Files MPLAB IDE MCHIP_Tools mpasmwin exe q p16F84A Example2 asm l Example2 Ist fe Executing C Program Files MPLAB IDE MCHIP_Tools mplink exe C Program Files MPLAB IDE MCHIP_Tools LKR 1 0 01 Linker oe 2004 Microchip Technology Inc Loaded DAPrajects32XExample cof BUILD SUCCEEDED Mon May 17 14 41 31 2004 Build Errors If the build did not complete successfully check these items 1 Review the previous steps in this example Make sure you have set up the language tools correctly and have all the correct project files and build options 2 If you modified the sample source code examine the Build tab of the Output win dow for syntax errors in the source code If you find any double click on the error to go to the source code line that contains that error Correct the error and then try to build again Output Files Vie
103. 05 Microchip Technology Inc DS33014J page 49 Assembler Linker Librarian User s Guide 4 5 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation badromis notcommonly used as RAM and ROM details are handled by the include files inc or linker script files 1kr 4 5 4 See Also maxrom 4 5 5 Simple Example Hinclude p12c508 inc _ maxrom 0x1FF _ badrom 0x2 0x4 OxA org 0x5 goto 0x2 generates a warning call 0x3 generates a warning org OxA moviw 5 generates a warning 4 6 bankisel GENERATE INDIRECT BANK SELECTING CODE PIC12 16 MCUs 4 6 1 Syntax bankisel label 4 6 2 Description This directive is an instruction to the assembler or linker to generate the appropriate bank selecting code for an indirect access of the register address specified by label Only one 1abe1 should be specified No operations can be performed on 1abe1 This label must have been previously defined The linker will generate the appropriate bank selecting code For 14 bit instruction width most PIC12 PIC16 devices the appropriate bit set clear instruction on the IRP bit in the STATUS register will be generated If the indirect address can be specified without these instructions no code will be generated 4 6 3 Usage This directive is used in the following types of code absolute or relocatable For information on
104. 09 CE ALORS EA shh E T 71 variable ccee eee 118 Aur EROS 72 Create Numeric and Text Data ccccccccccecceccececeeeeees 62 eC cM 72 Customer Notification Service sss 6 MOM ise siens ERE IU ITI 73 Customer Surprised dde tre 7 Ie S 73 Environment Variables 192 D equis cce ee eame 74 CAS esit tt EM LE que ca 61 SON rita oido inca 74 Data A ui 28 157 A en a ne etm e te 65 Grrorlevel 2 hti ftat os 76 EEPROM Byte 55 terere dites 67 Errors AoT ao Rte Re ERE nr ste 70 AsSembl t 3 5 5 i min pit inei tado 157 datas ER E 39 62 CORP E 221 Data Directives 46 COFF to COD Converter eeeeee 222 Dad Mina 48 Librarian Parse sens his con dea scada 233 badrom E ete 49 Library File needed 220 NECI 58 A tss 215 USOS n aes tp feeit etes 58 Linker Parse 213 3ldlOCS ei b rte epe erate de ses 87 Escape Sequences 40 E re ni 97 Examples Application ZMAXTOMES eoe ef e frt ea tdi ante 98 di deflne eite 69 132 136 ClO CK ORT 54 iINCIUdE a rss eec srteestessete 124 CONTI 22h pen dae 59 undefine occccccccccconononcccncnnnnncnnnnnnnnnaronnnnns 69 132 CA ter nette M Lea na Ein eo UE MEME at 61 DANKISE sii d tn da 51 52 datar sch cen is lea das 62 banksel 53 54 125 134 dbi ett tete tee
105. 1 The 111 directive is used to specify successive program memory locations with a constant or an assembly instruction For PIC18 devices only an even number is allowed to be specified as a count of locations to be filled include p18f452 inc Include standard header file for the selected device RST CODE 0x0000 The code section named RST is placed at program memory location 0x0 The instruction goto start is placed in code section RST goto start Jumps to the location labelled start fill 0 HI INT Fills 0 in 2 program memory locations 0004 and 0006 HI INT addr minus current addr HI INT CODE 0x0008 goto INTR H 2005 Microchip Technology Inc DS33014J page 83 Assembler Linker Librarian User s Guide fill goto start 6 Fills 6 locations each location is 2 bytes wide with 3 numbers of 2 word wide instructions goto start LO INT CODE 0x0018 goto INTR L fill 10a9 start Fills address 1Ch and 1Eh with 10a9h CODE 0x0020 start Write your main program here fill nop 4 Fills 2 locations 4 bytes with NOP goto Go to current line loop here INTR H Write your high interrupt ISR here retfie INTR L Write your low interrupt ISR here retfie end 4 34 global EXPORT A LABEL 4 34 4 Syntax global label label 4 34 2 Description This directive declares symbol names that are defined in the current module and should be available to other modules At least one
106. 128K bytes of the SRAM are not accessible and therefore the first addressable location of SRAM is 20000h TABLE 13 6 PROGRAM MEMORY MAP PIC18F8722 AND 1MB SRAM Program Memory SRAM Linker Script Section Source Code Section Address Address 0x000000 0x000029 0x000000 vectors Reset Interrupts vectors 0x00002A 0x01FFFF page On chip Memory prog Main Program 0x01FFFF 0x020000 0x020000 OxOFFFFF OxOFFFFF SRAM BASE ADDRS 0x100000 xsram External Memory SRAM END ADDRS 0x1FFFFF 13 6 8 MPASM Assembler Linker Script The modified PIC18F8722 MPASM linker script file shown below demonstrates suggested modifications for external memory applications Id 18 8722 1kr v 1 1 2004 09 09 21 22 33 curtiss Exp File 18 8722 1kr Sample linker script for the PIC18F8722 processor LIBPATH CODEPAGE NAME vectors START 0x0 END 0x29 PROTECTED CODEPAGE NAME page START 0x2A END 0x1FFFF CODEPAGE NAME xsram START 0x020000 END 0x1FFFFF PROTECTED CODEPAGE NAME idlocs START 0x200000 END 0x200007 PROTECTED CODEPAGE NAME config START 0x300000 END 0x30000D PROTECTED CODEPAGE NAME devid START 0x3FFFFE END 0x3FFFFF PROTECTED CODEPAGE NAME eedata START 0xF00000 END 0xF003FF PROTECTED ACCESSBANK NAME accessram START 0x0 END 0x5F DATABANK NAME gprO START 0x60 END 0xFF DATABANK NAME gpr1 START 0x100 END 0x1FF DATABANK NAME g
107. 13 5 14 MPASM Assembler Boot Loader Source Code In this example the boot loader is a single source file that will not be linked with any other source code at build time The CODE directives used in the boot loader source code instructs the linker to place the Reset and interrupt vectors at their appropriate program memory locations for the PIC microcontroller and to place the starting location of the boot loader executable code just above this region starting at location 002Ah The program memory section names Vectors IntH and IntL are used with the CODE directive to instruct the linker to place the assembled code that follows each directive at the specified program memory location In this case the boot loader is not linked with any application code so the relocated Reset and interrupt vectors 0208h 0218h and 022Ah are assumed and therefore are explicitly coded 18Fboot asm This is an example of how the startup portion of a boot loader could be configured when designing and programming only the boot loader code into the target PIC microcontroller kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk 18Fboot asm kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk LIST P 18F8722 include P18cxxx inc kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Vectors code 0x0000 VReset bra Boot Start IntH code 0x0008 VIntH bra 0x0208 Re map Interrupt vector to app s code s
108. 4 MPASM Assembler Boot Loader Source Code Example 2 shows a multiple module relocatable MPASM application See Section 13 5 15 MPASM Assembler Application Source Code Example 3 incorporates both the MPASM boot loader and multiple module relocatable MPASM application as a single program memory image See Section 13 5 16 MPASM Assembler Boot Loader Plus Application Source Code The modified linker script file provided in this example is designed to support all three of above scenarios See Section 13 5 13 MPASM Assembler Linker Script 13 5 12 MPASM Assembler Memory Map The boot loader typically resides in the boot block region of the PIC18F8720 s program memory which is the first 512 bytes of memory from location 0000h to 01FFh The remaining program memory starting at location 0200h is available for relocatable application code and data lookup tables Other PIC18F microcontrollers offer larger boot block regions and will require slightly different linker script modifications than what is represented in this example However the concepts shown here can be migrated to these other PIC microcontrollers This figure shows the PIC18F8720 memory mapping for a boot loader and application code 2005 Microchip Technology Inc DS33014J page 203 Assembler Linker Librarian User s Guide TABLE 13 4 PROGRAM MEMORY MAP PIC18F8720 Program Memory Linker Script Section Source Code Section Address 0x000
109. 44 2005 Microchip Technology Inc Instruction Sets TABLE A 8 PIC18 BYTE ORIENTED REGISTER OPERATIONS CONTINUED Hex Mnemonic Description Function 1Ff COMF d a Complement f NOT f gt dest 63 CPFSEQ f a Compare f with WREG skip if f WREG if f WREG PC 4 gt PC f WREG else PC 2 gt PC 65 CPFSGT f a Compare f with WREG skip if f gt f WREG if f gt WREG PC 4 gt PC WREG else PC 2 2 PC 61f CPFSLT f a Compare f with WREG skip if f lt f WREG if f lt WREG PC 4 gt PC WREG else PC 2 2 PC 07f DECF f d a Decrementf f 1 gt dest 2Ff DECFSZ d a Decrement f skip if O f 1 gt dest if dest 0 PC 4 gt PC else PC 2 gt PC AFf DCFSNZ d a Decrement f skip if not O f 1 gt dest if dest z0 PC 4 gt PC else PC 2 gt PC 2Bf INCF f d a Increment f f 1 gt dest 3Ff INCFSZ d a Increment f skip if O f 1 dest if dest 0 PC 4 PC else PC 2 gt PC ABf INFSNZ d a Increment f skip if not O f 1 gt dest if dest 0 PC 4 PC else PC 2 PC 13f IORWF d a Inclusive OR WREG with f WREG OR f gt dest 53f MOVF d a Movef f 2 dest Ct MOVFF f Move f to fd second word fof Ff 6Ff MOVWF f a Move WREG to f WREG gt f 03f MULWF f a Multiply W
110. 65 Assembler Linker Librarian User s Guide Ch strng contains three 14 bit numbers 004Dh 0043h and 0055h These are ASCII equivalents of M C and U respectively tb1 dta db 0 Oxff Places 00ff in program memory location end 4 16 7 PIC18 Application Example db This example shows the usefulness of directive db in storing one or more byte or character in program memory include p18f452 inc Include standard header file for the selected device ORG 0x0000 The following code will be programmed in reset address 0 goto start Jump to an address labelled Start start Write your main program here goto Go to current line loop here ORG 0x1000 Store the string starting from 1000H In PIC18 devices the first character is in least Significant byte Ch stng db Me POL V BEA Ch strng contains three 16 bit numbers 004Dh 0043h and 0055h These are ASCII equivalents of M C and U respectively Information on storing data in both bytes of a program word on the PIC18 architecture can be found in Section 4 10 code pack Begin an Object File Packed Code Section PIC18 MCUs tb1 dta db 0 Oxff Places ff00 in program memory location end DS33014J page 66 2005 Microchip Technology Inc Directives 4 17 de DECLARE EEPROM DATA BYTE 4 17 1 Syntax 1abel de expr expr expr 4 17 2 Description de Data EEPROM This directive can be used at any locat
111. 8080808034303E8E8FFDO 03003900FFFF19AD 00000001FF file name hxh 0A0000000000000000000000000000F6 1000190000000000000000010101010102020202CA 100029000202030303030304040404050607070883 0300390008080AAA 00000001FF 1 7 5 8 INTEL HEX 32 FORMAT The extended 32 bit address hex format is similar to the hex 8 format except that the extended linear address record is also output to establish the upper 16 bits of the data address This is mainly used for 16 bit core devices since their addressable program memory exceeds 64 kbytes Each data record begins with a 9 character prefix and ends with a 2 character checksum Each record has the following format BBAAAATTHHHH HHHCC where BB A two digit hexadecimal byte count representing the number of data bytes that will appear on the line AAAA A four digit hexadecimal address representing the starting address of the data record TT A two digit record type 00 Data record 01 End of File record 02 Segment Address record 04 Linear Address record HH A two digit hexadecimal data byte presented in low byte high byte combinations cc A two digit hexadecimal checksum that is the two s complement of the sum of all preceding bytes in the record 2005 Microchip Technology Inc DS33014J page 29 Assembler Linker Librarian User s Guide 1 7 6 Cross Reference File xrf A cross reference file contains a listing of all symbols used in the assembly code The
112. 8750 3506 Fax 86 591 8750 3521 China Hong Kong SAR Tel 852 2401 1200 Fax 852 2401 3431 China Qingdao Tel 86 532 502 7355 Fax 86 532 502 7205 China Shanghai Tel 86 21 5407 5533 Fax 86 21 5407 5066 China Shenyang Tel 86 24 2334 2829 Fax 86 24 2334 2393 China Shenzhen Tel 86 755 8203 2660 Fax 86 755 8203 1760 China Shunde Tel 86 757 2839 5507 Fax 86 757 2839 5571 China Wuhan Tel 86 27 5980 5300 Fax 86 27 5980 5118 China Xian Tel 86 29 8833 7250 Fax 86 29 8833 7256 ASIA PACIFIC India Bangalore Tel 91 80 2229 0061 Fax 91 80 2229 0062 India New Delhi Tel 91 11 5160 8631 Fax 91 11 5160 8632 India Pune Tel 91 20 2566 1512 Fax 91 20 2566 1513 Japan Yokohama Tel 81 45 471 6166 Fax 81 45 471 6122 Korea Seoul Tel 82 2 554 7200 Fax 82 2 558 5932 or 82 2 558 5934 Malaysia Penang Tel 604 646 8870 Fax 604 646 5086 Philippines Manila Tel 011 632 634 9065 Fax 011 632 634 9069 Singapore Tel 65 6334 8870 Fax 65 6334 8850 Taiwan Hsinchu Tel 886 3 572 9526 Fax 886 3 572 6459 Taiwan Kaohsiung Tel 886 7 536 4818 Fax 886 7 536 4803 Taiwan Taipei Tel 886 2 2500 6610 Fax 886 2 2508 0102 Thailand Bangkok Tel 66 2 694 1351 Fax 66 2 694 1350 EUROPE Austria Weis Tel 43 7242 2244 399 Fax 43 7242 2244 393 Denmark Copenhagen Tel 45 4450 2828 Fax 45 4485 2829 France Paris Tel 33 1 69 53 63 20 Fax 33 1 69 30 90 79
113. AB IDE to help you do this You may choose from simulators in circuit emulators or in circuit debuggers either manufactured by Microchip Technology or third party developers Please see the documentation for these tools to see how they can help you Once you have developed your code you will want to program it into a device Again there are several programmers that work with MPLAB IDE to help you do this Please see the documentation for these tools to see how they can help you For more information on using MPLAB IDE consult the on line help that comes with this application or download printable documents from our website Sa cC A M R M Pr o M 2005 Microchip Technology Inc DS33014J page 17 Assembler Linker Librarian User s Guide NOTES DS33014J page 18 2005 Microchip Technology Inc AN ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Part 1 MPASM Assembler Chapter 1 MPASM Assembler Overview eeeeeeeeeeeeeeeen nnne 29 Chapter 2 Assembler Interfaces nes 39 Chapter 3 Expression Syntax and Operation eese 47 Chapter 4 DIFGClV S sion ccr bin rro a ae Ek nce det ba vem Cal bx dede 53 Chapter 5 Assembler Examples Tips and Tricks 129 Chapter 6 Reloc
114. BLW kk Subtract WREG from literal kk WREG gt WREG OAkk XORLW kk Exclusive OR literal with WREG WREG XOR kk gt WREG TABLE A 12 PIC18 MEMORY OPERATIONS Hex Mnemonic Description Function 0008 TBLRD Table Read Prog Mem TBLPTR TABLAT 0009 TBLRD Table Read with post increment Prog Mem TBLPTR TABLAT TBLPTR 1 gt TBLPTR 000A TBLRD Table Read with post decrement Prog Mem TBLPTR gt TABLAT TBLPTR 1 TBLPTR 000B TBLRD Table Read with pre increment TBLPTR 1 gt TBLPTR Prog Mem TBLPTR TABLAT 000C TBLWT Table Write TABLAT gt Prog Mem TBLPTR 000D TBLWT Table Write with post increment TABLAT gt Prog Mem TBLPTR TBLPTR 1 gt TBLPTR 000E TBLWT Table Write with post decrement TABLAT gt Prog Mem TBLPTR TBLPTR 1 gt TBLPTR 000F TBLWT Table Write with pre increment TBLPTR 1 gt TBLPTR TABLAT gt Prog Mem TBLPTR 2005 Microchip Technology Inc DS33014J page 247 Assembler Linker Librarian User s Guide A 8 PIC18 DEVICE EXTENDED INSTRUCTION SET Some PIC18 devices have an extended mode of operation for use with the MPLAB C18 compiler This mode will change the operation of some instructions listed in Section A 7 PIC18 Device Instruction Set and add the instructions listed in this section In general you should not need to use the extended instruction set However if needed the extended mode is set using a special device configuration bit For more on
115. C18 C Compiler User s Guide DS51288 MPLAB C18 C Compiler Libraries DS51297 PIC18 Configuration Settings Addendum DS51537 MPLAB IDE Documentation Information on the integrated development environment MPLAB IDE may be found in MPLAB IDE Quick Chart DS51410 Chart for quick look ups MPLAB IDE User s Guide DS51519 Comprehensive user s guide MPLAB IDE Quick Start DS51281 Chapters 1 and 2 of the user s guide On line help file The most up to date information on MPLAB IDE PlCmicro MCU Data Sheets and Application Notes Data sheets contain information on device operation as well as electrical specifications Applications notes demonstrate how various PICmicro MCUs may be used Find both of these types of documents for your device on the Microchip website 2005 Microchip Technology Inc DS33014J page 5 Assembler Linker Librarian User s Guide THE MICROCHIP WEB SITE Microchip provides online support via our web site at www microchip com This web site is used as a means to make files and information easily available to customers Accessible by using your favorite Internet browser the web site contains the following information Product Support Data sheets and errata application notes and sample programs design resources user s guides and hardware support documents latest software releases and archived software General Technical Support Frequently Asked Questions FAQs techn
116. CII Character Set Hexadecimal to Decimal Conversion B 2 ASCII CHARACTER SET EA E 0 NUL DLE Most Significant Nibble p Space 0 P li 1 SOH DC1 1 A Q a q 2 STX DC2 2 B R 3 ETX DC3 3 C S 2 4 EOT DC4 4 D T 2 5 ENQ NAK 5 E U 6 6 F V 5 7 7 G w o E 8 8 H x E 9 HT EM 9 l Y A LF SUB J Z B VT ESC K k C FF FS lt L D CR GS M m E SO RS gt N A n F SI US O o DEL 2005 Microchip Technology Inc DS33014J page 249 Assembler Linker Librarian User s Guide B 3 HEXADECIMAL TO DECIMAL CONVERSION This appendix describes how to convert hexadecimal to decimal For each HEX digit find the associated decimal value Add the numbers together High Byte Low Byte HEX 1000 Dec HEX 100 Dec HEX 10 Dec HEX 1 Dec 0 0 0 0 0 0 0 0 1 4096 1 256 1 16 1 1 2 8192 2 512 2 32 2 2 3 12288 3 768 3 48 3 3 4 16384 4 1024 4 64 4 4 5 20480 5 1280 5 80 5 5 6 24576 6 1536 6 96 6 6 7 28672 7 1792 7 112 7 7 8 32768 8 2048 8 128 8 8 9 36864 9 2304 9 144 9 9 A 40960 A 2560 A 160 A 10 B 45056 B 2816 B 176 B 11 C 49152 C 3072 C 192 C 12 D 53248 D 3328 D 208 D 13 E 57344 E 3584 E 224 E 14 F 61440 F 3840 F 240 F 15 For example HEX A38F converts to 41871 as follows HEX 1000 s Digit HEX 100 s Digit HEX 10 s Digit HEX 1 s Digit Res
117. CROCHIP USER S GUIDE Chapter 16 Librarian Interfaces 16 1 INTRODUCTION How to use MPLIB librarian is discussed here For information on how librarian output can be used with the MPASM assembler and the MPLINK linker see the documentation for these tools Topics covered in this chapter MPLAB IDE Interface Command Line Options Command Line Examples and Tips 16 2 MPLAB IDE INTERFACE The MPLIB librarian may be used with MPLAB IDE to create a library file from project object files instead of an executable hex file With your project open in MPLAB IDE select Project gt Build Options Project In the Build Options dialog click on the MPASM C17 C18 Suite tab Click the radio button next to Build library target invoke MPLIB Then click OK Now when you build your project you will be building a library file 2005 Microchip Technology Inc DS33014J page 231 Assembler Linker Librarian User s Guide 16 3 COMMAND LINE OPTIONS MPLIB librarian is invoked with the following syntax mplib q ctdrx LIBRARY MEMBER Options Option Description Detail c Create library Creates a new LIBRARY with the listed MEMBER s d Delete member Deletes MEMBER s from the LIBRARY if no MEMBER is specified the LIBRARY is not altered q Quiet mode No output is displayed JE Add replace member If MEMBER s exist in the LIBRARY then they are replaced otherwise MEMBER is appended to the end of th
118. Caveats Linker Script 183 zZinclude xs m itte 92 143 0 8 a10 ets Eoo S A ELE A ms 54 HUNOCTING peton ce ta eta 117 Code Qtr eiut desi a ec Here id nr M d 43 Absol te eie 144 147 149 150 CLIPS E EE ee metre Re TERT 12 Relocatable 144 147 149 Qui MILAN MEME NAE M MR te Moa 12 Relocatable Defining Module 148 lex RE PE ENTER T 12 Relocatable Library Routine 151 oec ECCE S 12 Relocatable Referencing Module 148 ere ERR S 12 174 1016 MUR mA re tr iio 56 144 148 QD ND MD 12 GOde Section a deri em 56 m 150 Code Section Packed sese 57 DadLlarm tite ad 48 Code Sections mariin nectit etn itte cbe reote 129 Dad Min da 49 Code pack iii ai a 57 o ioe 58 148 CGODEPAGE 3 nette tet 184 185 SES AAA ne A 58 COFF Object Module File sess 174 Mer RH 87 148 Command Line Interface 2 maxtalm nuuc EE hated 97 Assembler eet 35 O 98 E TEETE EAEE 232 A ANA AE EEEE EEE E E EE AE A es 179 Command Line Options Librarian Absolute Code Generating 22 A E E 232 Access Section RN O neue pt 232 Overlayed sssseeennennenn 48 d lcu e cU ua 232 ACCESS race 48 A AS 232 ACCESSBANK seen 183 185 RU tbt tu a Mr LEE 232 Accessing Labels From Other Modules 148 D ON ETE oca Did 232 Allocation Co
119. Command Line Hex file format Choose the linker hex file format or suppress output of the hex file Generate map file Create a map file A map file provides information on the absolute location of source code symbols in the final output It also provides information on memory use indicating used unused memory Suppress COD file Do not generate a COD file generation Note The COD file name including the path has a 62 character limit The COFF file does not have this limitation Note This will also cause the linker list file to not be generated This does not affect assembler list file generation Output file root Enter a root directory for saving output files Restore Defaults Restore tab default settings Use Alternate Settings Text Box Enter options in a command line non GUI format Build Options Dialog MPASM C17 C18 Suite Tab Determine if the files in the project will be built for normal output using the linker hex file etc or if they will be build into a library using the MPLIB librarian lib file PROJECT EXAMPLE In this example you will create an MPLAB IDE project with multiple assembly files Therefore you will need to use the MPASM assembler and the MPLINK linker to create the final output executable hex file Run the Project Wizard Set Build Options Build the Project Build Errors Output Files Further Development Run the Project Wizard In MPLAB IDE select
120. Description A delay routine is needed in many applications For this example delay increments are 20 us with the routine having a range of 40 us to 23 8 hours This assumes a 4 MHz clock 5 5 2 Commented Code Listing Each loop takes 20 clocks or 20 us per loop at 4MHz or 1MIPS clock Turn off in config bits WDT for long simulations Hinclude p16F877A inc udata 0x20 DlyO res HE Stores 4 bytes of data for the delay count Dlyl res 1 DlyO is the least significant byte Dly2 res 1 while Dly3 is the most significant byte Dly3 res 1 Dly32 MACRO DLY goto 1 delay 2 cycles goto 1 delay total of 4 cycles Take the delay value argument from the macro precalculate the required 4 RAM values and load the The RAM values Dly3 though Dlyo BANKSEL Dly3 movlw DLY 1 amp H FF movwf Dlyo movlw DLY 1 gt gt D 08 H FF movwf Dly1 movlw DLY 1 gt gt D 16 H FF Bytes are shifted and anded by the assembler to make user calculations easier movwf Dly2 movlw DLY 1 gt gt D 24 H FF Call DoD1y32 to run the delay loop movwf Dly3 call DoD1y32 ENDM End of Macro definition RST CODE 0x00 Reset Vector pagesel TestCode goto TestCode CODE Code starts here TestCode Dly32 D 50000 Max 4 billion runs D1y32 Macro l sec in this case nop ZERO STOPWATCH put breakpoint here DS33014J page 134 2005 Microchip Technology Inc Assembler Examples Tips and Tricks
121. E AN ERROR MESSAGE 4 28 4 Syntax error text string 4 28 2 Description text stringis printed in a format identical to any MPASM assembler error message text string may be from 1 to 80 characters DS33014J page 74 2005 Microchip Technology Inc Directives 4 28 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation You can use this directive to generate errors for yourself or others who build your code You can create any error message you wish as long as it is no longer than 80 characters 4 28 4 See Also messg if 4 28 5 Simple Example error checking macro argl if argl gt 55 if arg is out of range error error checking 01 arg out of range endif endm 4 28 6 Application Example error This program demonstrates the error assembler directive which sets an error message to be printed in the listing file and error file include p16f877a inc Include standard header file for the selected device variable baudrate variable used to define required baud rate baudrate set D 5600 Enter the required value of baud rate here if baudrate D 1200 amp amp baudrate D 2400 amp amp baudrate D 4800 amp amp baudrate D 9600 amp amp baudrate D 19200 error Selected baud rate is not supported endif The if endif code above outputs error if the baud rate select
122. EGA 2 BSF REGB 5 BSF REGB 5 4 instructions 3 instructions One technique for moving one bit from the REGA register to REGB is to perform bit tests In the first example the bit in REGA is tested using a BTFSS instruction If the bit is clear the BCF instruction is executed and clears the REGB bit and if the bit is set the instruction is skipped The second bit test determines if the bit is set and if so will execute the BSF and set the REGB bit otherwise the instruction is skipped This sequence requires four instructions DS33014J page 140 2005 Microchip Technology Inc Assembler Examples Tips and Tricks A more efficient technique is to assume the bit in REGA is clear and clear the REGB bit and test if the REGA bit is clear If so the assumption was correct and the BSF instruction is skipped otherwise the REGB bit is set The sequence in the second example uses three instructions because one bit test was not needed One important point is that the second example will create a two cycle glitch if REGB is a port outputting a high This is caused by the BCF and BTFSC instructions that will be executed regardless of the bit value in REGA 5 9 4 TIP 4 Swap File Register with W The following macro swaps the contents of W and REG without using a second register SWAPWF MACRO REG XORWF REG F XORWF REG W XORWF REG F ENDM Needs 0 TEMP registers 3 Instructions 3 Tcy An efficient way of swapping the content
123. Errors Library File Errors COFF File Errors 17 2 LIBRARIAN PARSE ERRORS MPLIB librarian parse errors are listed alphabetically below Invalid Object Filename All object filenames must end with o Invalid Switch An unsuppported switch was specified For a list of supported swtiches refer to command line options Library Filename is Required All commands require a library filename All library filenames must end with lib 17 3 LIBRARY FILE ERRORS For a list of library file errors see Section 14 5 Library File Errors 17 4 COFF FILE ERRORS For a list of COFF File Errors see Section 14 6 COFF File Errors 2005 Microchip Technology Inc DS33014J page 233 Assembler Linker Librarian User s Guide NOTES DS33014J page 234 2005 Microchip Technology Inc AN ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Part 4 Appendices Appendix A Instruction Sets icon 243 Appendix B Useful Tables eeeeee eere ce eeeeeeneeeee nennen 255 2005 Microchip Technology Inc DS33014J page 235 Assembler Linker Librarian User s Guide NOTES DS33014J page 236 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Appendix A Instruction Sets A 1 INTRODUCTION PICmicro MCU instruction sets are used in developing applications with MPASM assembler MPLINK object linker and MPLIB object librarian Instruc
124. Example if rate lt 50 incf speed F else decf speed F endif 4 21 6 Application Example if else endif See this example under if 4 22 end END PROGRAM BLOCK 4 22 4 Syntax end 4 22 2 Description Indicates the end of the program 4 22 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation You will need at least one ena directive in any assembly program to indicate the end of a build In a single assembly file program one and only one end must be used 2005 Microchip Technology Inc DS33014J page 71 Assembler Linker Librarian User s Guide Be careful not to include files which contain end as assembly will be prematurely stopped 4 22 4 See Also org 4 22 5 Simple Example include p18f452 inc executable code end end of instructions 4 23 endc END AN AUTOMATIC CONSTANT BLOCK 4 23 4 Syntax endc 4 23 2 Description endc terminates the end of a cblock list It must be supplied to terminate the list 4 23 3 Usage This directive is used in the following types of code absolute For information on types of code see Section 1 6 Assembler Operation For every cblock directive used there must be a corresponding endc 4 23 4 See Also cblock 4 23 5 Examples See the examples under cblock 4 24 endif END CONDITIONAL ASSEMBLY BLOCK 4 24 4 Syntax Preferred endif Supp
125. Expressions may be literal strings and are stored as described in the ab data directive 4 20 8 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation When generating a linkable object file this directive can also be used to declare initialized data values Refer to the idata directive for more information While db is more common to use you may use dw to store data in Flash PIC16FXXX devices as many of these devices can read all 14 bits of a program memory word at run time See the PIC16F877A data sheet for examples and more information 4 20 4 See Also data db idata DS33014J page 70 2005 Microchip Technology Inc Directives 4 20 5 Simple Example dw 39 diagnostic 39 0x123 dw diagbase 1 4 24 else BEGIN ALTERNATIVE ASSEMBLY BLOCK TO i CONDITIONAL 4 21 4 Syntax Preferred else Supported else else 4 21 2 Description Used in conjunction with an if directive to provide an alternative path of assembly code should the if evaluate to false else may be used inside a regular program block or macro 4 213 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is not an instruction It is used to perform conditional assembly of code 4 21 4 See Also endif if 4 21 5 Simple
126. F d Add W and f W f gt d O5df ANDWF F d AND W andf W AND f gt d 01 1 f CLRF F Clear f 0f 01xx CLRW Clear W 0 gt W 09df COMF F d Complement f NOT f gt d 03df DECF F d Decrement f f 1 gt d OBdf DECFSZ F d Decrement f skip if zero f 1 gt d skip if O OAdf INCF F d Increment f f 1 gt d OFdf INCFSZ F d Increment f skip if zero f 1 gt d skip if O 04df IORWF F d Inclusive OR W and f W OR f gt d o8df MOVF f d Movef fod 00 1 f MOVWF f Move W to f Wf 0000 NOP No operation ODdf RLF f d Rotate left f register f CE 7 0 E DS33014J page 240 2005 Microchip Technology Inc Instruction Sets TABLE A 4 14 BIT BYTE ORIENTED FILE REGISTER OPERATIONS CONTINUED Hex Mnemonic Description Function ocaf RRF d Rotate right f register f LZ 7 0 02df SUBWF f d Subtract W from f f Wod OEdf SWAPF fd Swap halves f f 0 3 O f 4 7 gt d 06df XORWF f d Exclusive OR W and f W XOR f gt d TABLE A 5 14 BIT BIT ORIENTED FILE REGISTER OPERATIONS Hex Mnemonic Description Function 4bf BCF f b Bit clear f 0 gt f b 5bf BSF f b Bit set f 1 gt f b 6bf BTFSC ED Bit test skip if clear skip if f b O 7bf BTFSS f b Bit test skip if set skip if f b 1 TABLE A 6 14 BIT LITERAL AND CONTROL OPERATIONS Hex Mnemonic Description Function 3Ekk ADDLW kk Add literal to W kk
127. H CODEPAGE NAME vector START 0x0 END 0x29 PROTECTED CODEPAGE NAME boot code START 0x2A END 0x1FF PROTECTED CODEPAGE NAME r vectors START 0x200 END 0x229 PROTECTED CODEPAGE NAME user code START 0x22A END 0x1EFFFF CODEPAGE NAME const START 0x1F0000 END 0x1FFFFF PROTECTED CODEPAGE NAME idlocs START 0x200000 END 0x200007 PROTECTED CODEPAGE NAME config START 0x300000 END 0x30000D PROTECTED CODEPAGE NAME devid START 0x3FFFFE END 0x3FFFFF PROTECTED CODEPAGE NAME eedata START 0xF00000 END 0xF003FF PROTECTED ACCESSBANK NAME accessram START 0x0 END 0x5F DATABANK NAME gpr0 START 0x60 END 0xFF DATABANK NAME gpri START 0x100 END 0x1FF DATABANK NAME gpr2 START 0x200 END 0x2FF DATABANK NAME gpr3 START 0x300 END 0x3FF DATABANK NAME gpr4 START 0x400 END 0x4FF DATABANK NAME gpr5 START 0x500 END 0x5FF DATABANK NAME gpr6 START 0x600 END 0x6FF DATABANK NAME gpr7 START 0x700 END 0x7FF DATABANK NAME gpr8 START 0x800 END 0x8FF DATABANK NAME gpr9 START 0x900 END 0x9FF DS33014J page 204 O 2005 Microchip Technology Inc Sample Applications DATABANK NAME gpr10 START 0xA00 END 0xAFF DATABANK NAME gpr11 START 0xB00 END 0xBFF DATABANK NAME gpr12 START 0xC00 END 0xCFF DATABANK NAME gpr13 START 0xD00 END 0xDFF DATABANK NAME gpr14 START 0xE00 END 0xEFF DATABANK NAME gpr15 START 0xF00 END 0xF5F ACCESSBANK NAME accesssfr START 0xF60 END 0xFFF PROTECTED SECTION NAME CONFIG ROM config
128. M in this field press Tab For more information on this file type see Section 1 7 1 Source Code asm Set the various options as described below Option Description Processor Type If you do not specify the processor in your source file use this field to select the processor Enter the field by using the arrow keys then toggle through the supported processors by pressing lt Enter gt Error File An error file sourcename err is created by default For more information on this file type see Section 1 7 4 Error File err To turn the error file off use the keyboard arrow keys to move to the field and press lt Enter gt to change it to No The error filename can be changed by pressing the lt Tab gt key to move to the shaded area and typing a new name Wild cards are not allowed in the error filename 2005 Microchip Technology Inc DS33014J page 33 Assembler Linker Librarian User s Guide Option Description Cross Reference File A cross reference file sourcename xrf is not generated by default For more information on this file type see Section 1 7 6 Cross Reference File xrf To create a cross reference file use the keyboard arrow keys to move to the field and press Enter to change it to Yes The cross reference filename can be changed by pressing the Tab key to move to the shaded area and typing a new name Wild cards are not allowed in the cross
129. M space for dynamic stack usage Identifies Address Conflicts Checks to ensure that program data do not get assigned to space that has already been assigned or reserved Provides Symbolic Debug Information Outputs a file that MPLAB IDE uses to track address labels variable locations and line file information for source level debugging 2005 Microchip Technology Inc DS33014J page 171 Assembler Linker Librarian User s Guide 9 4 HOW MPLINK LINKER HELPS YOU MPLINK linker allows you to produce modular reusable code Control over the linking process is accomplished through a linker script file and with command line options The linker ensures that all symbolic references are resolved and that code and data fit into the available PlCmicro MCU device MPLINK linker can help you with Reusable Source Code You can build up your application in small reusable modules Libraries You can make libraries of related functions which can be used in creating efficient readily compilable applications MPLAB C18 The Microchip compiler for PIC18 devices requires the use of MPLINK linker and can be used with precompiled libraries and MPASM assembler Centralized Memory Allocation By using application specific linker scripts precompiled objects and libraries can be combined with new source modules and placed efficiently into available memory at link time Accelerated Development Since tested modules and libraries don t have to be recomp
130. MI AMI MI DATABANK NAME gprO DATABANK NAME gpr1 DATABANK NAME gpr2 DATABANK NAME gpr3 DATABANK NAME gpr4 DATABANK NAME gpr5 DATABANK NAME gpr6 DATABANK NAME gpr7 DATABANK NAME gpr8 DATABANK NAME gpr9 DATABANK NAME gpr10 DATABANK NAME gpr11 DATABANK NAME gpr12 DATABANK NAME gpr13 DATABANK NAME gpr14 ACCESSBANK NAME accesssfr SECTION NAME CONFIG SECTION NAME STARTUP SECTION NAME PROG SECTION NAME INTHAND SECTION NAME DATTBL STACK SIZE 0x100 RAM gpr14 13 4 4 START 0x0 START 0x2A START 0x20000 START 0x200000 START 0x300000 START 0x3FFFFE START 0xF00000 START 0x0 START 0x60 START 0x100 START 0x200 START 0x300 START 0x400 START 0x500 START 0x600 START 0x700 START 0x800 START 0x900 START 0xA00 START 0xB00 START 0xC00 START 0xD00 START 0xE00 START 0xF60 ROM config ROM vectors ROM page ROM eeprom ROM eeprom zu D 0x29 D 0x1FFFF D 0x1FFFFF D 0x200007 D 0x30000D D 0x3FFFFF D 0xF003FF 22 zu E HE Ed Bd b bd pd zu zu zu zu D 0x5F D 0xFF D 0x1FF D 0x2FF D 0x3FF D 0x4FF D 0x5FF D 0x6FF D 0x7FF D 0x8FF D 0x9FF D OxAFF D OxBFF D OxCFF D OxDFF D OxEFF D OxFFF 2 4 4 2 4 2 2 2 4 2 A uu ELE ES MEUBLE EU EE zu PROT PROT PROT PROT PROT TECTED TECTED TECTED TECTED TECTED PRO ECTED PROTECTED Reset and interrupt vectors main application code spa
131. NSTANT cannot be reassigned after having been initialized once So lngth and wdth cannot be reassigned But perimeter has been declared as variable and so can be reassigned area lngth wdth end 4 67 while PERFORM LOOP WHILE CONDITION IS TRUE 4 67 4 Syntax Preferred while expr And Supported while expr endw 4 67 2 Description The lines between the while and the endw are assembled as long as expr evaluates to TRUE An expression that evaluates to zero is considered logically FALSE An expression that evaluates to any other value is considered logically TRUE A relational TRUE expression is guaranteed to return a non zero value FALSE a value of zero 2005 Microchip Technology Inc DS33014J page 119 Assembler Linker Librarian User s Guide A while loop can contain at most 100 lines and be repeated a maximum of 256 times while loops can be nested up to 8 deep 4 67 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is not an instruction but used to control how code is assembled not how it behaves at run time Use this directive for conditional assembly 4 67 4 See Also endw if 4 67 5 Simple Example whi le is not executed at run time but produces assembly code based on a condition View the list file 1st or disassembly window to see the results of this e
132. OP cycle is the second cycle of a two cycle instruction Since the PlCmicro microcontroller architecture is pipelined it prefetches the next instruction in the physical address space while it is executing the current instruction However if the current instruction changes the program counter this prefetched instruction is explicitly ignored causing a forced NOP cycle GPR General Purpose Register The portion of device data memory RAM available for general use Halt A stop of program execution Executing Halt is the same as stopping at a breakpoint Hex Code Executable instructions stored in a hexadecimal format code Hex code is contained in a hex file Hex File An ASCII file containing hexadecimal addresses and values hex code suitable for programming a device High Level Language A language for writing programs that is further removed from the processor than assembly ICD In Circuit Debugger MPLAB ICD 2 is Microchip s in circuit debugger ICE In Circuit Emulator MPLAB ICE 2000 and 4000 are Microchip s in circuit emulators DS33014J page 254 2005 Microchip Technology Inc Glossary IDE Integrated Development Environment MPLAB IDE is Microchip s integrated development environment Import Bring data into the MPLAB IDE from an outside source such as from a hex file Instruction Set The collection of machine language instructions that a particular processor understands Instructions A se
133. Overlaying access sections allows you to reuse access bank data space 4 3 4 See Also extern global udata udata ovr udata acs 4 3 5 Simple Example The 2 indentically named sections are overlayed in PIC18 Access RAM In this example ul a is overlaid with memory locations used by ua8 and u8b ul6b is overlaid with memory locations used by u8c and u8d myaoscn access ovr uga res 1 u8b res 1 u8c res 1 u8d res 1 myaoscn access_ovr ul6a res 2 ul6b res 2 44 badram IDENTIFY UNIMPLEMENTED RAM Note badramis preceded by two underline characters 4 4 1 Syntax badram expr expr exprl exprl DS33014J page 48 O 2005 Microchip Technology Inc Directives 4 4 2 Description The maxramand badran directives together flag accesses to unimplemented registers __badram defines the locations of invalid RAM addresses This directive is designed for use with the maxram directive maxram directive must precede any badram directive Each expr must be less than or equal to the value specified by maxram Oncethe maxram directive is used strict RAM address checking is enabled using the RAM map specified by badram To specify a range of invalid locations use the syntax minloc maxloc 4 4 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation badramis not commonly used as RAM and ROM deta
134. Project Project Wizard to launch the wizard Click Next at the Welcome screen 1 Select PIC16F84A as the Device Click Next to continue 2 Setupthe language tools if you haven t already Refer to MPLAB IDE Setup Click Next to continue 3 Enter Example for the name of the project Then Browse to select a location for your project Click Next to continue _ L X X EE gssg s pe xr DS33014J page 14 2005 Microchip Technology Inc PlCmicro Language Tools and MPLAB IDE 4 Add files to the project a In the file listing box on the left of the dialog find the following directory C Program Files Microchip MPASM Suite EXAMPLE Select Example asm and Example2 asm Click Add gt gt to add these files to the project b In the file listing box on the left of the dialog find the following directory C Program Files Microchip MPASM SuitelLKR Select 16 84a 1kr Click Add gt gt to add this file to the project c Check the checkbox next to each file to make a copy of each file in the project directory This will preserve the original files Click Next gt to continue 5 Review the summary of information If anything is in error use Back to go back and correct the entry Click Finish to complete the proj
135. REG OR f gt dest 22f MOVF f d Move f f gt dest 02 MOVWF f Move W to f WREG f 000 NOP No operation 36f RLF f d Rotate left f register f C lt _ EE 0 32f RRF f d Rotate right f register f ue E 0 OAf SUBWF d Subtract W from f f WREG gt dest 3Af SWAPF fod Swap halves f f 0 3 O f 4 7 gt dest 1Af XORWF d Exclusive OR W and f WREG XOR f gt dest Assuming default bit value for d TABLE A 2 12 BIT BIT ORIENTED FILE REGISTER OPERATIONS Hex Mnemonic Description Function 4bf BCF f b Bit clear f 0 gt f b 5bf BSF f b Bit set f 1 f b 6bf BTFSC f b Bit test skip if clear skip if f b 0 7bf BTFSS f b Bit test skip if set skip if f b 1 O 2005 Microchip Technology Inc DS33014J page 239 Assembler Linker Librarian User s Guide TABLE A 3 12 BIT LITERAL AND CONTROL OPERATIONS Hex Mnemonic Description Function Ekk ANDLW kk AND literal and W kk AND WREG gt WREG 9kk CALL kk Call subroutine PC 1 TOS kk PC 004 CLRWDT Clear watchdog timer 0 WDT and Prescaler if assigned Akk GOTO kk Goto address k is nine bits kk PC 9 bits Dkk IORLW kk Incl OR literal and W kk OR WREG gt WREG Ckk MOVLW kk Move Literal to W kk gt WREG 002 OPTION Load OPTION Register WREG gt OPTION Register 8kk RETLW kk Return with literal in W kk WREG TOS gt PC 003 SLEEP Go into S
136. REG with f WREG f gt PRODH PRODL 6Df NEGF f a Negate f fof 37 RLCF d a Rotate left f through Carry register f C 44 Jis 0 48 47 RLNCF d a Rotate left f no carry register f E ics ts 0 33f RRCF d a Rotate right f through Carry register f Te exu 0 43f RRNCF d a Rotate right f no carry register f fati EA d eth 0 L 34 69f SETF f a Set f OxFF f 57 SUBFWB d a Subtract f from WREG with WREG f C gt dest Borrow 5Ff SUBWF d a Subtract WREG from f f WREG gt dest 5Bf SUBWFB d a Subtract WREG from f with f WREG C dest Borrow 3Bf SWAPF d a Swap nibbles of f f 3 0 gt dest lt 7 4 gt f lt 7 4 gt gt dest lt 3 0 gt 67 TSTFSZ f a Test f skip if O PC 4 PC iff 0 else PC 2 PC 1Bf XORWF d a Exclusive OR WREG with f WREG XOR f gt dest Assuming default bit values for d and a 2005 Microchip Technology Inc DS33014J page 245 Assembler Linker Librarian User s Guide TABLE A 9 PIC18 BIT ORIENTED REGISTER OPERATIONS Hex Mnemonic Description Function 91f BCF f b a Bit Clear f 0 gt f lt b gt 81f BSF b a BitSetf 1 gt f lt b gt B1f BTFSC f b a Bit test f skip if clear if f lt b gt 0 PC 4 gt PC else PC 2 gt PC Alf BTFSS b a Bit test f skip if set if f lt b gt 1 PC 4 gt PC else PC 2 PC 71 BTG f b a Bit Toggle f f lt b
137. RGB1 Clear partial product before testing movlw D 11 movwf AARGBO movlw D 30 movwf BARGBO call UMULO808L After loading AARGBO and BARGBO call routine goto Result now in AARGBO AARGB1 where BO is MSB END UMULO808L movlw 0x08 movwf LOOPCOUNT movf AARGBO W LOOPUMO808A LEE BARGBO F btfsc STATUS C goto LUMO808NAP decfsz LOOPCOUNT F goto LOOPUMO808A clrf AARGBO retlw 0x00 LUMO 808NAP bcf STATUS C goto LUMO808NA DS33014J page 150 2005 Microchip Technology Inc Relocatable Objects LOOPUMO808 rrf BARGBO F btfsc STATUS C addwf AARGBO F LUMO808NA rrr AARGBO F wa AARGB1 F decfsz LOOPCOUNT F goto LOOPUMO808 retlw 0 END EXAMPLE 6 10 RELOCATABLE CODE CALLING FILE Input fixed point arguments in AARGBO and BARGBO Output product AARGxBARG in AARGBO AARGB1 Other comments truncated See AN617 PRR RRR RE RRE ke ke e ke ke Sk ce he ke he ke e he ke ke ke he ke e he ke ke che ke ke he he ke e he KE he ke he he ke ke he ke ce RARA Hinclude p16f877a inc Use any PIC16 device you like EXTERN UMULO808L AARGBO AARGB1 BARGBO Reset CODE 0x0 pagesel TestCode goto TestCode CODE TestCode banksel AARGB1 clrf AARGB1 Clear partial product before testing movlw D 11 Load in 2 test values movwf AARGBO movlw D 30 movwf BARGBO pagesel UMULO808L call UMULO808L After loading AARGBO and BARGBO Call routine goto Result now in AARGBO AARGB1 whe
138. RODUCTION Linker script files are the command files of the linker They specify Program and data memory regions for the target part Stack size and location for MPLAB C18 A mapping of logical sections in source code into program and data regions Linker script directives form the command language that controls the linker s behavior There are four basic categories of linker script directives Each of these directives plus some useful linker script caveats are discussed in the topics listed below Note Linker script comments are specified by i e any text between a and the end of a line is ignored Topics covered in this chapter Standard Linker Scripts Linker Script Command Line Information Linker Script Caveats Memory Region Definition Logical Section Definition STACK Definition 11 2 STANDARD LINKER SCRIPTS Standard linker script files are provided for each device and are located by default in the directory C Program Files Microchip MPASM Suite LKR Special linker scripts are provided for use with MPLAB C18 that set up a software stack see Section 11 7 STACK Definition These files are located by default in the directory c Nmcc18 Ml kr The linker script files are as follows Use PIC10 12 16 PIC18 General DevNum lkr DevNum lkr DevNum e lkr MPLAB ICD 2 DevNumi 1kr DevNumi 1kr DevNumi e lkr DevNum the number associated with the
139. Set the size of tabs in the list file using the t option EXAMPLE 1 2 ABSOLUTE MPASM ASSEMBLER LISTING FILE The product name and version the assembly date and time and the page number appear at the top of every page The first column contains the base address in memory where the code will be placed The second column displays the 32 bit value of any symbols created with the set equ variable constant Or cblock directives The third column is reserved for the machine instruction This is the code that will be executed by the PlCmicro MCU The fourth column lists the associated source file line number for this line The remainder of the line is reserved for the source code line that generated the machine code DS33014J page 26 2005 Microchip Technology Inc MPASM Assembler Overview Errors warnings and messages are embedded between the source lines and pertain to the following source line Also there is a summary at the end of the listing The symbol table lists all symbols defined in the program The memory usage map gives a graphical representation of memory usage X marks a used location and marks memory that is not used by this object The map also displays program memory usage The memory map is not printed if an object file is generated Note Due to page width restrictions some comments have been shortened indi cated by Also some symbol table listings have been removed indicated by
140. T In the MPLAB IDE installation source code templates and linker script templates are provided for most devices supported by MPLAB IDE These templates give you a starting point from which to begin coding and to learn about linker scripts You are encouraged to modify both the source code template and the linker template to fit your needs In fact some of the provided linker script files must be edited in order to successfully build with the provided source code templates In this first example a build error will be analyzed and the linker script will be modified to rectify the error so that a successful build can be completed 13 3 1 Locating Template Files For MPLAB IDE installed in the default location source code templates may be found at C Program Files Microchip MPASM Suite Template in the following subdirectories Code Contains absolute assembly code examples by device Object Contains relocatable assembly code examples by device The relocatable source code template 877atempo asm for the PIC16F877A may be found in the Object directory This template defines an absolute code section for the reset vector at address 0x0 an absolute code section for the interrupt vector at address 0x04 and a relocatable code section for main For MPLAB IDE installed in the default location linker script templates may be found at C Program Files Microchip MPASM Suite LKR The linker script template 16 877a 1kr for the PIC16F877A may
141. T P 18F8722 include P18cxxx inc Define labels here but used outside this module global RVReset RVIntH RVIntL kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk R_vectors code 0x200 RVReset Re mapped RESET vector bra main R_IntH code 0x208 Re mapped HI priority interrupt vector RVIntH High priority interrupt vector code here Fp x e retfie R IntL code 0x218 Re mapped LOW priority interrupt vector RVIntL Low priority interrupt vector code here Pisces retfie 2005 Microchip Technology Inc DS33014J page 207 Assembler Linker Librarian User s Guide user code code 0x22A main Entry into application code starts here end of main code section kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkxkxk ND BE gt gt gt 13 5 17 Building the MPASM Assembler Application To build the MPASM assembler sample application refer to Section 13 2 How to Build the Sample Applications The linker script file for this sample application is a modification of the standard linker file for the device and is named boot 1kr 13 6 SAMPLE APPLICATION 4 CONFIGURING EXTERNAL MEMORY Most of the larger pin count PIC microcontrollers have the ability to interface to external 8 or 16 bit data Flash or SRAM memories through the External Memory Bus EMB The PIC18F8722 for example has 128K bytes of internal program memory 00000h 1FFFFh But whe
142. The entire program memory is mapped externally Mnemonics Text instructions that can be translated directly into machine code Also referred to as Opcodes MPASM Assembler Microchip Technology s relocatable macro assembler for PICmicro microcontroller devices KeeLoq devices and Microchip memory devices MPLAB ASM30 Microchip s relocatable macro assembler for dsPIC30F digital signal controller devices MPLAB C1X Refers to both the MPLAB C17 and MPLAB C18 C compilers from Microchip MPLAB C17 is the C compiler for PIC17 devices and MPLAB C18 is the C compiler for PIC18 devices MPLAB C30 Microchip s C compiler for dsPIC30F digital signal controller devices MPLAB ICD 2 Microchip s in circuit debugger that works with MPLAB IDE The ICD supports Flash devices with built in debug circuitry The main component of each ICD is the module A complete system consists of a module header demo board cables and MPLAB IDE Software MPLAB ICE 2000 4000 Microchip s in circuit emulators that works with MPLAB IDE MPLAB ICE 2000 sup ports PlCmicro MCUs MPLAB ICE 4000 supports PIC18F MCUs and dsPIC30F DSCs The main component of each ICE is the pod A complete system consists of a pod processor module cables and MPLAB IDE Software MPLAB IDE Microchip s Integrated Development Environment MPLAB LIB30 MPLAB LIB30 archiver librarian is an object librarian for use with COFF object modules created using either MPLAB ASM30 or MPLAB C30 C
143. To generate a file that will execute after being programmed into a device see 1 7 5 Hex File Formats hex hxl hxh To prevent object file generation use the o option EEE K M A Ndg n es Rp ge E DS33014J page 30 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 2 Assembler Interfaces INTRODUCTION There are several interfaces with which you may use the MPASM assembler depending on the assembler version These interfaces are discussed here When MPLAB IDE is installed the windowed version of the MPASM assembler mpasmwin exe is also installed In addition the windowed version and the command line version mpasm exe of the assembler may be obtained with the regular and demo version of the MPLAB C18 C compiler Topics covered in this chapter MPLAB IDE Interface Windows Interface Command Shell Interface Command Line Interface Troubleshooting MPLAB IDE INTERFACE The MPASM assembler is most commonly used with the MPLINK linker in an MPLAB IDE project to generate relocatable code For more information on this use see PlCmicro Language Tools and MPLAB IDE The assembler may also be used in MPLAB IDE to generate absolute code without the use of the MPLINK linker or MPLAB IDE project by using the QuickBuild feature To do thi
144. X Is overridden by command line option y disable extended instruction set Note Processor type is set in MPLAB IDE Configure gt Device r radix hex Set radix hex dec oct See also radix st ON OFF On Print symbol table in list file t ON OFF Off Truncate lines of listing otherwise wrap w 0 1 2 0 Set the message level See also errorlevel 2005 Microchip Technology Inc DS33014J page 93 Assembler Linker Librarian User s Guide Option Default Description x ON OFF On Turn macro expansion on or off Note All list options are evaluated as decimal numbers by default 4 42 4 See Also errorlevel expand noexpand nolist processor radix 4 42 5 Simple Example Set the processor type to PIC18F452 the hex file output format to INHX32 and the radix to decimal list p 18f452 f INHX32 r DEC 4 43 local DECLARE LOCAL MACRO VARIABLE 4 43 1 Syntax Preferred local label label Supported local label label 4 43 2 Description Declares that the specified data elements are to be considered in local context to the macro label may be identical to another label declared outside the macro definition there will be no conflict between the two If the macro is called recursively each invocation will have its own local copy 4 43 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of
145. abel Syntax O 2005 Microchip Technology Inc DS33014J page 117 Assembler Linker Librarian User s Guide 4 65 2 Description label is an identifier previously defined with the define directive The symbol named is removed from the symbol table 4 65 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is most often used with the ifdef and i fndef directives which look for the presence of an item in the symbol table 4 65 4 See Also Hdefine include ifdef ifndef 4 65 5 Simple Example define length 20 undefine length 4 65 6 Application Example define undefine See this example under define 4 66 variable DECLARE SYMBOL VARIABLE 4 66 1 Syntax variable label s sexpr l label sexpr l 4 66 2 Description Creates symbols for use in MPASM assembler expressions Variables and constants may be used interchangeably in expressions The variable directive creates a symbol that is functionally equivalent to those created by the set directive The difference is that the variable directive does not require that symbols be initialized when they are declared The variable values cannot be updated within an operand You must place variable assignments increments and decrements on separate lines 4 66 3 Usage This directive is used in the following types of code absolute or reloc
146. adixfor numeric constants can be made different from the default radix specified with the directives radix or list r Also allowable default radices are limited to hexadecimal decimal and octal Constants can be optionally preceded by a plus or minus sign If unsigned the value is assumed to be positive Note Intermediate values in constant expressions are treated as 32 bit unsigned integers Whenever an attempt is made to place a constant in a field for which it is too large a truncation warning will be issued 2005 Microchip Technology Inc DS33014J page 41 Assembler Linker Librarian User s Guide The following table presents the various radix specifications TABLE 3 3 RADIX SPECIFICATIONS MPASM ASSEMBLER MPLINKTM LINKER Note Type Syntax Example 1 Binary B binary digits B 00111001 2 Octal O octal digits O 777 3 Decimal D digits digits D100 100 H 9f Ox9f Hexadecimal H hex digits Oxhex digits ASCII A character character A C LIC 3 5 A binary integer is b or B followed by one or more of the binary digits 01 in single quotes An octal integer is o or O followed by one or more of the octal digits 01234567 in single quotes A decimal integer is d or D followed by one or more decimal digits 0123456789 in single quotes Or a decimal integer is followed by one or m
147. after a semicolon as acomment All characters following the semicolon are ignored through the end of the line String constants containing a semicolon are allowed and are not confused with comments 1 7 2 Include File inc An assembler include or header file is any file containing valid assembly code Usually the file contains device specific register and bit assignments This file may be included in the code so that it may be reused by many programs As an example to add the standard header file for the PIC18F452 device to your assembly code use include p18f452 inc Standard header files are located in C Program Files Microchip MPASM Suite 1 7 3 Listing File Ist An MPASM assembler listing file provides a mapping of source code to object code It also provides a list of symbol values memory usage information and the number of errors warnings and messages generated This file may be viewed in MPLAB IDE by 1 Selecting File gt Open to launch the Open dialog 2 Selecting List files Ist from the Files of type drop down list 3 Locating the desired list file 4 Clicking on the list file name 5 Clicking Open Both the MPASM assembler and the MPLINK linker can generate listing files For information on the MPLINK linker listing file see 9 7 7 Listing File Ist To prevent assembler list file generation use the 1 option or use with MPLINK linker the linker list file overwrites the assembler list file
148. age of program memory no code will be generated For PIC18 devices this command will do nothing as these devices do not use paging 2005 Microchip Technology Inc DS33014J page 103 Assembler Linker Librarian User s Guide 4 52 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation This directive saves you from having to manually code page bit changes Also since it automatically generates code the code is much more portable If you are using relocatable code and your device has more than 2k program memory or 0 5K for 12 bit instruction width devices it is recommended that you use this directive especially when code must jump between two or more code sections If you wish to indicate the start address of a RETLW table or a jump table for computed GOTOs you must use the pageselw directive 4 52 4 See Also bankisel banksel 4 52 5 Simple Example pagesel GotoDest goto GotoDest pagesel CallDest call CallDest 4 52 6 Application Example pagesel This program demonstrates the pagesel directive which generates the appropriate code to set clear PCLATH bits This allows easier use of paged memory such as found on PIC16 devices Hinclude p16f877a inc Include standard header file for the selected device RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructi
149. al or decimal So by default sit is in hex as default radix is declared as hex end 4 56 res RESERVE MEMORY 4 56 1 Syntax label res mem units 4 56 2 Description Causes the memory location pointer to be advanced from its current location by the value specified in mem units In relocatable code using MPLINK linker res can be used to reserve data storage In non relocatable code 1abe1 is assumed to be a program memory address Address locations are defined in words for PIC12 16 MCUS and bytes for PIC18 MCUs 4 56 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation The most common usage for res is for data storage in relocatable code 2005 Microchip Technology Inc DS33014J page 107 Assembler Linker Librarian User s Guide 4 56 4 See Also fill org equ cblock 4 56 5 Simple Example buffer res 64 reserve 64 address locations of storage 4 56 6 Application Example res This example shows the advantage of res directive in developing relocatable code The program calculates the perimeter of a rectangle Length and width of the rectangle will be stored in buffers addressed by 1ength and width The calculated perimeter will be stored in the double precision buffer addressed by perimeter include p18f452 inc Include standard header file for the selected device UDATA This directive allows
150. ames Assembler 41 Reserved Words Assembler 41 ROM Memory Regions Defining 184 S Sample Applications Linker 191 Scripts Linker suisses 181 Search Order Include Files 92 SECTION fo einige ea repe 183 185 SOL encode tete du ris ens 109 Set Program Origin sssssesss 100 SHAREBANK is 183 185 Simple o ise nis m Ue 49 50 Source Code nn dte ones 12 Source Code File Assembly 24 SDaC6 mn RADIO bte enn 110 Se e o la 186 STACK SIZE ius 186 Standard Linker Scripts 181 Store Strings in Program Memory 61 Subtitle 4 158 aote enia dant ele er 110 Symbol and Debug File 30 174 Symbol Constant 60 Symbols In Expressions 42 T Table Define ocn irt errore tan 70 Text Strings iunii recie oet pe eost 39 Text Substitution Label 68 i e 111 Troubleshooting 157 U e iei reete eee eren eR NS ERR Os Qeon asa redit 111 147 udala acs sete ta 112 147 udata OVE ici 114 147 Udala Shri eerte tec ft 116 147 urideflne ses etit rette nine 117 Unimplemented RAM 48 Unimplemented ROM 49 UDDOF nete idet b P e d eet ie Seabee 43 145 V Variable Declare dada eid 118 Bf sean te der E 109 Localia 94 o ii atit iR PORE 118
151. another Sa cA H A P n ae 2005 Microchip Technology Inc DS33014J page 255 Assembler Linker Librarian User s Guide Linker Script Files Linker script files are the command files of a linker They define linker options and describe available memory on the target platform Listing Directives Listing directives are those directives that control the assembler listing file format They allow the specification of titles pagination and other listing control Listing File A listing file is an ASCII text file that shows the machine code generated for each C source statement assembly instruction assembler directive or macro encountered in a source file Local Label A local label is one that is defined inside a macro with the LOCAL directive These labels are particular to a given instance of a macro s instantiation In other words the symbols and labels that are declared as local are no longer accessible after the ENDM macro is encountered Logic Probes Up to 14 logic probes can be connected to some Microchip emulators The logic probes provide external trace inputs trigger output signal 5V and a common ground Machine Code The representation of a computer program that is actually read and interpreted by the processor A program in binary machine code consists of a sequence of machin
152. art high Return high byte of section start address scnstart upper Return upper byte of section start address Operand precedence information may be found in 3 5 Arithmetic Operators and Precedence DS33014J page 144 2005 Microchip Technology Inc Relocatable Objects There are some restrictions involving these operands with relocatable symbols For example the 1ow high and upper operands must be of the form low high upper relocatable symbol constant offset where relocatable symbol is any label that defines a program or data memory address constant offset is an expression that is resolvable at assembly time to a value between 32768 and 32767 Either relocatable symbol Or constant offset may be omitted Operands of the form relocatable symbol relocatable symbol will be reduced to a constant value if both symbols are defined in the same code or data section In addition to section operands there are section pseudo instructions Pseudo Instruction Definition scnend lfsr scnend lfsr n s where nis 0 1 or 2 as with the LFSR instruction and s is a string which is taken to be the name of a section This instruction loads LFSR with the end address of the section scnstart lfsr scnstart lfsr n s where nis 0 1 or 2 as with the LFSR instruction and s is a string which is taken to be the name of a section This instruction loads LFSR with the start address of the section
153. at will always be 00 except for the end of file record which will be 01 HH A two digit hexadecimal data byte presented in low byte high byte combinations cc A two digit hexadecimal checksum that is the two s complement of the sum of all preceding bytes in the record M s i I AA DS33014J page 28 2005 Microchip Technology Inc MPASM Assembler Overview EXAMPLE 1 3 INHX8M file name hex 1000000000000000000000000000000000000000F0 0400100000000000EC 100032000000280040006800A800E800C80028016D 100042006801A9018901EA01280208026A02BF02C5 10005200E002E80228036803BF03E803C8030804B8 1000620008040804030443050306E807E807FF0839 06007200FF08FF08190A57 00000001FF 1 7 5 2 INTEL SPLIT HEX FORMAT The split 8 bit file format produces two output files hx1 and hxh The format is the same as the normal 8 bit format except that the low bytes of the data word are stored in the hx1 file and the high bytes of the data word are stored in the hxh file and the addresses are divided by two This is used to program 16 bit words into pairs of 8 bit EPROMs one file for low byte one file for high byte EXAMPLE 1 4 INHX8S file name hxl 0A0000000000000000000000000000F6 1000190000284068A8E8C82868A989EA28086ABFAA 10002900E0E82868BFE8C
154. atable For information on types of code see Section 1 6 Assembler Operation This directive is most used for conditional assembly code Note variable is not used to declare a run time variable but a variable that is used by the assembler To create a run time variable refer to the directives res equ Or cblock 4 66 4 See Also constant set 4 66 5 Simple Example variable RecLength 64 Set Default RecLength constant BufLength 512 Init BufLength DS33014J page 118 2005 Microchip Technology Inc Directives RecLength may be reset later in RecLength 128 constant MaxMem RecLength BufLength CalcMaxMem 4 66 6 Application Example variable constant This example shows the usage of the variable directive used for creating symbols which may be used in MPASM assembler expressions only The symbols created with this directive do not occupy any physical memory location of the microcontroller include p16f877a inc Include standard header file for the selected device variable perimeter 0 The symbol perimeter is initialized to 0 variable area If a symbol is declared as variable then initialization is optional i e it may or may not be initialized constant Ingth 50H The symbol lngth is initialized to 50H constant wdth 25H The symbol wdth is initialized to 25H A constant symbol always needs to be initialized perimeter 2 lngth wdth The value of a CO
155. atable Objects eeeeeeeeeeeeeeeeeeeeeeeenee nenne 149 Chapter 7 Macro Language sense 159 Chapter 8 Errors Warnings Messages and Limitations 163 2005 Microchip Technology Inc DS33014J page 19 Assembler Linker Librarian User s Guide NOTES DS33014J page 20 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 1 MPASM Assembler Overview 1 1 INTRODUCTION An overview of the MPASM assembler and its capabilities is presented Topics covered in this chapter MPASM Assembler Defined How MPASM Assembler Helps You Assembler Migration Path Assembler Compatibility Issues Assembler Operation Assembler Input Output Files 1 2 MPASM ASSEMBLER DEFINED The MPASM assembler the assembler is a command line or Windows based PC application that provides a platform for developing assembly language code for Microchip s PICmicro microcontroller MCU families There are two executable versions of the assembler The windows version mpasmwin exe Use this version with MPLAB IDE in a stand alone Windows application or on the command line This version is available with MPLAB IDE or with the regular and demo version of the MPLAB C18 C compiler This is the recommended version The command line version mpasm exe Use this version on the command line either from a command shell or directly on the
156. ates a packed 14 bit number representing two 7 bit ASCII characters Hinclude p16f877a inc Include standard header file for the selected device ORG 0x0000 The following code will be O 2005 Microchip Technology Inc DS33014J page 61 Assembler Linker Librarian User s Guide programmed in reset address 0 goto start Jump to an address labelled testare s start Write your main program here goto Go to current line loop here ORG 0x1000 Store the string starting from 1000H Ch stng da PICmicro Directive da produces four 14 bit numbers 2849 21ED 34E3 and 396F representing the ASCII equivalent of PI Cm ic and ro See below for more information Sngl ch da A 7 bit ASCII equivalents of A and a NULL charater will be packed in a 14 bit number da Oxff55 Places 3f55 in program memory No packing end Determining 14 Bit Numbers For the following statement Ch stng da PICmicro directive da produces four 14 bit numbers 2849 21ED 34E3 and 396F representing the ASCII equivalent of PI Cm ic and ro To see how the 14 bit numbers are determined look at the ASCII values of P and I which are 50h 01010000 and 49h 01001001 respectively Each is presented in 7 bit as 0 1010000 and 0 1001001 respectively The packed 14 bit number is 101000 01001001 which is stored as 00 101000 01001001 or 2849 4 15 data CREATE NUMERIC AND TEXT DATA 415 1 Syntax label data expr expr expr
157. ations Only one linked module can specify these directives They should be used prior to declaring any code sections After using these directives the current section is undefined 6 7 ACCESSING LABELS FROM OTHER MODULES Labels that are defined in one module for use in other modules must be exported using the global directive see 4 34 global Export a Label Modules that use these labels must use the extern directive see 4 32 extern Declare an Externally Defined Label to declare the existence of these labels An example of using the global and extern directives is shown below EXAMPLE 6 6 RELOCATABLE CODE DEFINING MODULE udata InputGain res 1 OutputGain res 1 global InputGain OutputGain code Filter global Filter Filter code EXAMPLE 6 7 RELOCATABLE CODE REFERENCING MODULE extern InputGain OutputGain Filter udata Reading res 1 code movlw GAIN1 movwf InputGain movlw GAIN2 movwf OutputGain DS33014J page 148 2005 Microchip Technology Inc Relocatable Objects movf Reading W call Filter 6 8 PAGING AND BANKING ISSUES In many cases RAM allocation will span multiple banks and executable code will span multiple pages In these cases it is necessary to perform proper bank and page set up to properly access the labels However since the absolute addresses of these variable and address labels may not be known at assembly time it is not always possible to place the proper code in th
158. ble hex file directly MPASM assembler routines designed for absolute address assembly will require minor modifications to compile correctly into relocatable object modules Topics covered in this chapter Header Files Program Memory Low High and Upper Operands RAM Allocation Configuration Bits and ID Locations Accessing Labels From Other Modules Paging and Banking Issues Generating the Object Module Code Example 6 2 HEADER FILES The Microchip supplied standard header files e g p18 8720 inc should be used when generating object modules These header files define the special function registers for the target processor EXAMPLE 6 1 INCLUDE HEADER FILE Hinclude p18f8720 inc See 4 41 include Include Additional Source File for more information O 2005 Microchip Technology Inc DS33014J page 143 Assembler Linker Librarian User s Guide 6 3 PROGRAM MEMORY Program memory code must be organized into a logical code section To do this the code must be preceded by a code section declaration See 4 9 code Begin an Object File Code Section to make it relocatable Absolute Code Equivalent Relocatable Code Start clrw code Address determined option by the linker Start clrw option Prog1 org 0x0100 Progl code 0x0100 Start at 0x0100 movlw 0x0A movlw Ox0A movwf varl movwf vari If more than one code section is defined in a source file each section must have a unique
159. by the xsram codepage directive at 20000h Since the memory region occupied by the SRAM is program memory not data memory the rom qualifier is required in the declaration of the char array variable sram In addition this memory region is beyond a 16 bit address range 64Kbyte and therefore requires the use of the far qualifier in order for C pointers to correctly access this region pragma romdata SRAM BASE Assigns this romdata space at 0x020000 rom far char sram Declare an array at starting address DS33014J page 208 2005 Microchip Technology Inc Sample Applications 13 6 2 MPLAB C18 Memory Map The table below shows the memory mapping for the PIC18F8722 when used with the 1Mbyte external SRAM device Notice that the first 128K bytes of the external memory region is overlapped with the 128K bytes of internal program memory space and therefore cannot be accessed using the external memory bus Without any additional external memory address decoding the first 128K bytes of the SRAM are not accessible and therefore the first addressable location of SRAM is 20000h TABLE 13 5 PROGRAM MEMORY MAP PIC18F8722 AND 1 MB SRAM Program SRAM Memory Linker Script Section Source Code Section Address Address 0x000000 0x000029 0x000000 vectors Reset Interrupts 0x00002A 0x01 FFFF 0x01 FFFF 0x020000 0x020000 OxOFFFFF OxOFFFFF 0x100000 Ox1FFFFF page On chip Memory xsram External Memory
160. c file e g bar c or MPASM assembler s CONFIG directive in a asm file e g bar asm Set configuration bits by using only one of CONFIG DECL pragma config or CONFIG directive TRIS argument is out of range OXHHHH not between OXHHHH and OXHHHH Check the device data sheet to determine acceptable hex values for the TRIS register you are using Undefined CODEPAGE memName for SECTION secName A SECTION directive with a ROM attribute refers to a memory block which has not been defined Add a CODEPAGE directive to the linker command file for the undefined memory block Undefined DATABANK SHAREBANK memName for SECTION secName A SECTION directive with a RAM attribute refers to a memory block that has not been defined Add a DATABANK or SHAREBANK directive to the linker command file for the undefined memory block Undefined DATABANK SHAREBANK memName for STACK No input object files specified At least one object module must be specified either on the command line or in the linker command file using the FILES directive Unknown section type for secName The section type for secName needs to be defined Unknown section type for secName in file filename An input object or library module is not of the proper file type or it may be corrupted Unsupported processor type in file filename A processor was specified that is not currently supported by the linker See the Readme file for a list of support
161. cated an error is generated Since absolute sections can only be allocated at a fixed address assigned and unassigned sections are performed in no particular order 12 3 2 Relocatable Allocation Once all absolute sections have been allocated the linker allocates relocatable assigned sections For relocatable assigned sections the linker checks the assigned target memory block to verify that there is space available otherwise an error is generated The allocation of relocatable assigned sections occurs in the order in which they were specified in the linker command file After all relocatable assigned sections have been allocated the linker allocates relocatable unassigned sections The linker starts with the largest relocatable unassigned section and works its way down to the smallest relocatable unassigned section For each allocation it chooses the target memory block with the smallest available space that can accommodate the section By starting with the largest section and choosing the smallest accommodating space the linker increases the chances of being able to allocate all the relocatable unassigned sections 12 3 3 Stack Allocation The stack is not a section but gets allocated along with the sections The linker command file may or may not assign the stack to a specific target memory block If the stack is assigned a target memory block it gets allocated just before the relocatable assigned sections are allocated If the stack
162. ce Interrupt handlers Data tables Building the Application To build the application see Section 13 2 How to Build the Sample Applications Then to continue development with MPLAB IDE 1 Though the configuration bits in code set the microcontroller mode to external you must tell MPLAB IDE the range of external memory you wish to use Select Configure External Memory In the dialog click Use External Memory and enter Ox1FFFFF as the Address Range End Click OK 2 Select Project gt Build Allto build the application again 2005 Microchip Technology Inc DS33014J page 197 Assembler Linker Librarian User s Guide 13 5 SAMPLE APPLICATION 3 USING A BOOT LOADER A boot loader is a special program that when programmed into the target PIC microcontroller is responsible for downloading and programming relocatable application code into the same target PIC microcontroller The relocatable application or user code is typically transferred to the boot loader through serial communications such as RS232 13 5 1 MPLAB C18 Usage There are three MPLAB C18 examples showing how to modify the MPLAB C18 linker scripts and how to use the pragma code directive in the source code for an MPLAB C18 boot loader project Example 1 shows how to configure an MPLAB C18 linker script and suggests how to use code directives for an MPLAB C18 boot loader See Section 13 5 3 MPLAB C18 Boot Loader Linker Script and Se
163. ce file macro expansion settings Reference Section 4 31 expand Expand Macro Listing DS33014J page 32 2005 Microchip Technology Inc Assembler Interfaces Option Description Processor Override any source file processor settings Extended Mode Enable PIC18F extended instruction support Extra Options Any additional command line options Reference Section 2 5 Command Line Interface Save Settings on Exit Save these settings in mplab ini They will be used the next time you run mpasmwin exe 2 4 COMMAND SHELL INTERFACE The MPASM assembler command shell interface displays a screen in Text Graphics mode It is invoked by executing mpasm exe in Windows Explorer On this screen you can fill in the name of the source file you want to assemble and other available options FIGURE 2 2 TEXT GRAPHICS MODE DISPLAY ini xi MPASM 63 66 Released lt c gt 1993 2B83 Microchip Technology Inc Byte Craft Li Source File Processor Type Error File Cross Reference File Listing File Hex Dump Type Assemble to Object File O Move Cursor Esc Quit Type the name of your source file He Fi Fi Assemble Type the name of your source file after Source File The name can include a DOS path and wild cards If you use wild cards one of or a list of all matching files is displayed for you to select from To automatically enter AS
164. ce this register is in bank 1 not default bank 0 banksel is used to ensure bank bits are correct clrf TRISB Clear TRISB Sets PORTB to outputs banksel PORTB banksel used to return to bank 0 where PORTB is located movlw 0x55 Set PORTB value movwf PORTB goto end All programs must have an end cblock DEFINE A BLOCK OF CONSTANTS 4 8 1 Syntax cblock expr label increment label increment endc 4 8 2 Description Defines a list of named sequential symbols The purpose of this directive is to assign address offsets to many labels The list of names ends when an endc directive is encountered expr indicates the starting value for the first name in the block If no expression is found the first name will receive a value one higher than the final name in the previous cblock If the first cblock in the source file has no expr assigned values start with zero If increment is specified then the next 1abe1 is assigned the value of increment higher than the previous label Multiple names may be given on a line separated by commas cblock is useful for defining constants in program and data memory for absolute code generation 4 8 3 Usage This directive is used in the following types of code absolute For information on types of code see Section 1 6 Assembler Operation Use this directive in place of or in addition to the equ directive When creating non relocatable absolute code cblock i
165. control of listing and hex file output 2005 Microchip Technology Inc DS33014J page 223 Assembler Linker Librarian User s Guide NOTES DS33014J page 224 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Part 3 MPLIB Object Librarian Chapter 15 MPLIB Librarian Overview eeeeueeeeee eere 233 Chapter 16 Librarian Interfaces sise 237 Chapter 17 e 239 2005 Microchip Technology Inc DS33014J page 225 Assembler Linker Librarian User s Guide NOTES DS33014J page 226 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 15 MPLIB Librarian Overview 15 1 INTRODUCTION An overview of the MPLIB object librarian and its capabilities is presented Topics covered in this chapter What is MPLIB Librarian How MPLIB Librarian Works How MPLIB Librarian Helps You Librarian Operation Librarian Input Output Files 15 2 WHAT IS MPLIB LIBRARIAN MPLIB object librarian the librarian combines object modules generated by the MPASM assembler or the MPLAB C18 C compiler into a single library file This file may then be inputted into the MPLINK object linker 15 3 HOW MPLIB LIBRARIAN WORKS A librarian manages the creation and modification of library files A library file is simply a collection of object modules that are stored in a single file There are several reasons for creat
166. cs 229 Linker tenet ane En eere 173 Instruction Operands ocoonccccncccoccconccconccnanacancnonananns 144 Instruction Sets iet e tt 237 T2 Bit Core uec 239 242 12 Bit 14 Bit Cores ener 242 14 Bit Gore e e etri teet 240 PIC18 Device e a aaite 243 2005 Microchip Technology Inc DS33014J page 267 Internet Address Microchip 6 Interrupt Handling PIC16 Example 77 83 101 126 131 PIC18 Example sees 83 102 L EIBBEATES iui se o To Toi e aero Es ES 182 Library File renes 12 174 229 Limitations AsSembler rta E mto tivo drca 168 Linker Processing 187 Linker Scripts oocoonoccconoccccoocccononcnnnannnconnnos 12 174 181 Linker Scripts Standard 181 MS li 93 Listing Directives 47 GITOE ii it eet ettet tene se et eie e ences ee unie 74 errorlevel ee t e ve secet err 76 IIS ORNE beet eget 93 ImessQ ett tete vd 98 hOoliSt ane rer eee tore tet Pets 100 page eene mn Ant 103 Space ini 110 SUbtle x3 veto sn UE 110 lila cre nd E Le dra 111 Listing File eR 26 47 174 ARPA rr sihi ot Sto Se cet cde ee 182 local iiic oic A eta eon c reri 94 Logical Sections 185 QA MH 43 145 M Macro Code Examples ocooococcconcccnoccnoncconcnonnnnnnnnnancnnns 155 End e oe neto eie eter 73 Exil Minn ee SANTA Ne dE ee nr 78 Expand die encre duet 80 No Expansion see
167. ct linker For more information on the assembler see the MPASM assembler documentation The C source file main c is also shown with its associated MPLAB C18 C compiler MPLAB IDE will use this information to generate an object file main o for input into the MPLINK object linker For more information on the compiler see the MPLAB C18 C compiler documentation listed in Recommended Reading In addition precompiled object files precomp o may be included in a project with no associated tool required For example MPLAB C18 requires the inclusion of a precompiled standard code module c018i o For more information on available Microchip precompiled object files see the MPLAB C18 C compiler documentation Some library files math 1ib are available with the compiler Others may be built using the librarian tool MPLIB object librarian For more information on the librarian see the MPLIB librarian documentation For more information on available Microchip libraries see the MPLAB C18 C compiler documentation The object files along with library files and a linker script file device 1kr are used to generate the project output files via the linker MPLINK object linker For more information on linker script files and using the linker see the MPLINK linker documentation The main output file generated by the MPLINK linker is the hex file prog hex used by simulators emulators debuggers and programmers For more information on linker o
168. ction 13 5 4 MPLAB C18 Boot Loader Source Code Example 2 shows the MPLAB C18 linker script configuration and suggested code directives for an MPLAB C18 application targeted for a microcontroller that is running an MPLAB C18 boot loader See Section 13 5 5 MPLAB C18 Application Linker Script and Section 13 5 6 MPLAB C18 Application Source Code Example 3 is a mixed language example using an MPLAB C168 application targeted for a microcontroller such as the PIC18F8720 with a limited boot block size running an MPASM boot loader A boot loader written in C code will typically require more program memory than a boot loader written in assembly and therefore requires a microcontroller with a larger boot block region such as the PIC18F8722 See Section 13 5 7 Mixed Language MPLAB C18 Application Linker Script Section 13 5 8 Mixed Language MPLAB C18 c018i c Modifications and Section 13 5 9 Mixed Language MPLAB C18 Application Source Code Boot loader and application code written tor MPLAB C18 must use the MPLAB C18 linker scripts to command the linker to place the compiled C source code into appropriate program memory sections Typically boot loader code is compiled and linked for a destination in the boot section of the target microcontroller s program memory The application code is compiled and linked for a destination inside the user section of program memory 13 5 2 MPLAB C18 Memory Map The firsttwo MPLAB C18 boot loader e
169. ction name in string table Unable to find symbol name in string table 2005 Microchip Technology Inc DS33014J page 221 Assembler Linker Librarian User s Guide 14 7 COFF TO COD CONVERSION ERRORS Source file filename name exceeds file format maximum of 63 characters The COD file name including the path has a 63 character limit Coff file filename must contain at least one code or romdata section In order to convert a COFF file to a COD file the COFF file must have either a code or a romdata section Could not open list file filename for writing Verify that if filename exists and that it is not a read only file 14 8 COFF TO COD CONVERTER WARNINGS Could not open source file filename This file will not be present in the list file The referenced source file could not be opened This can happen if an input object library module was built on a machine with a different directory structure If source level debugging for the file is desired rebuild the object or library on the current machine 14 9 COD FILE ERRORS All the COD file errors listed below indicate an internal error in the file s contents Please contact Microchip support if any of these errors are generated Cod file filename does not have a proper debug message table e Cod file filename does not have a proper Index Cod file filename does not have a proper line info table Cod file filename does not have a pro
170. d 15 5 LIBRARIAN OPERATION Below is a diagram of how the MPLIB librarian works with other Microchip tools mult c avg asm add asm Source files rr Oo y o MPASM MPASM MPLAB C18 Assembler Assembler Y Y Y mult o avg o add o object files Y MPLIB Librarian math lib library file The librarian combines multiple input object modules generated by the MPASM assembler or MPLAB C18 C compilers into a single output library lib file Library files are used in conjunction with the MPLINK linker to produce executable code DS33014J page 228 2005 Microchip Technology Inc MPLIB Librarian Overview 15 6 LIBRARIAN INPUT OUTPUT FILES The MPLIB librarian combines multiple object files into one library lib file Input Files Object File 0 Relocatable code produced from source files Output Files Library File lib A collection of object files grouped together for convenience 15 6 14 Object File o Object files are the relocatable code produced from source files The MPLIB librarian combines several object files into a single library file 15 6 2 Library File lib A library file may be created from object files by the MPLIB librarian or may be an existing standard library 2005 Microchip Technology Inc DS33014J page 229 Assembler Linker Librarian User s Guide NOTES DS33014J page 230 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MI
171. d Check that the file exists is in the current search path and is readable Illegal filename for FILES in cmdfile line An object or library filename must end with o or lib respectively Illegal filename for INCLUDE in cmdfile line A linker command filename must end with 1kr Illegal lt libpath gt for LIBPATH in cmdfile line The ibpath must be a semicolon delimited list of directories Enclose directory name which have embedded spaces in double quotes Illegal lt Ikrpath gt for LKRPATH in cmdfile line The krpath must be a semicolon delimited list of directories Enclose directory names which have embedded spaces in double quotes Invalid attributes for memory in cmdfile line A CODEPAGE DATABANK or SHAREBANK directive does not specify a NAME START or END attribute or another attribute is specified which is not valid 2005 Microchip Technology Inc DS33014J page 213 Assembler Linker Librarian User s Guide Invalid attributes for SECTION in cmdfile line A SECTION directive must have a NAME and either a RAM or ROM attribute Invalid attributes for STACK in cmdfile line A STACK directive does not specify a SIZE attribute or another attribute is specified which is not valid k switch requires lt pathlist gt A semicolon delimited path must be specified Enclose directory names containing embedded spaces with double quotes For example k c mylkr c program fil
172. d messages as this can make debugging of your code more difficult The most common usage for this directive is to suppress MESSAGE 302 Operand Not in bank 0 check to ensure bank bits are correct See the Simple Example for how to do this 4 29 4 See Also list error 4 29 5 Simple Example errorlevel 302 Turn off banking message known tested good code errorlevel 302 Enable banking message untested code hd 4 29 6 Application Example errorlevel This program demonstrates the errorlevel assembler directive which sets the type of messages that are printed in the listing file and error file include p16f877a inc Include standard header file for the selected device errorlevel 0 Display print messages warnings and errors messg CAUTION This program has errors display on build This message will display print for error level 0 DS33014J page 76 2005 Microchip Technology Inc Directives errorlevel 1 Display print only warnings and errors messg CAUTION This program has errors display message This message will NOT display print for error level 1 or 2 groupl udata 0x20 groupl varl res 1 Label of this directive is not at column 1 This will generate ja warning number 207 Warning 207 will display print for error level O or 1 errorlevel 207 groupl var2 res 1 errorlevel 207 group2 udata errorlevel 2 group2 varl res 1 This disables warning who
173. d to the proper size For example a 14 bit instruction would be truncated to 12 bits to be used by a PIC16F54 304 ID Locations value too large Last four hex digits used Only four hex digits are allowed for the ID locations 305 Using default destination of 1 file If no destination bit is specified the default is used Usually code that causes this message is missing the Wor F after the register name but sometimes the bug is due to typing mov instead of movwf It is best to fix any code that is causing this message The default destination could not be where you want the value stored and could cause the code to operate strangely 306 Crossing page boundary ensure page bits are set Generated code is crossing a page boundary This is a reminder message to tell you that code is being directed to a label that is on a page other than page 0 It is not an error or warning but a reminder to check your page bits Use the pagesel directive Section 4 52 pagesel Generate Page Selecting Code PIC10 12 16 MCUs before this point and remember to use another pagesel if returning to page O DS33014J page 166 2005 Microchip Technology Inc Errors Warnings Messages and Limitations The assembler can t tell what path your code will take so this message is generated for any label in a page other than 0 You can use the errorlevel command to turn this and other messages on and off but be careful as you may not s
174. data section are allocated group2 var2 res 1 automatically by the linker RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start Start PGM CODE This is the begining of the code section named PGM It is a relocatable code section since no absolute address is given along with directive CODE start banksel groupl_varl clrf groupl varl clrf groupl var2 banksel group2 varl clrf group2 varl clrf group2 var2 goto Go to current line loop here end DS33014J page 112 2005 Microchip Technology Inc Directives 4 62 udata acs BEGIN AN OBJECT FILE ACCESS UNINITIALIZED DATA SECTION PIC18 MCUs 4 62 41 Syntax 1abel udata acs RAM address 4 62 2 Description This directive declares the beginning of a section of access uninitialized data If 1abe1 is not specified the section is named udata_acs The starting address is initialized to the specified address or will be assigned at link time if no address is specified This directive is used to declare variables that are allocated in access RAM of PIC18 devices No code can be generated in this segment The res directive should be used to reserve space for data Note Two sections in the same source file are not permitted to have the same name 4 62 3 Usage This directive is used in the following
175. data table in program memory in the same code page with the interrupt handlers The data table is defined in C using the pragma romdata directive to place the table in a section called DATTBL The linker script file maps the DATTBL section to the CODE region that begins at 0x20000 Additionally configuration bits are set in C using the pragma config directive The main function in the C file is placed in the default CODE section because there is no section directive explicitly assigned For additional information you may wish to reference PIC18F8720 Device Data Sheet DS39609 MPLAB C18 C Compiler User s Guide DS51288 External Memory Interfacing Techniques for the PIC18F8XXX AN869 TABLE 13 2 PROGRAM MEMORY MAP PIC18F8720 Program Memory Linker Script Section Source Code Section Address E vectors Reset Interrupts STARTUP D IREEE page On chip Memory PROG Main Application Code 0x020000 rom External Memor INTHAND Interrupt Handler 0x1FFFFF p y DATTBL Data Table ne idlocs ID Locations COD config Configuration Bits CONFIG Configuration Settings P EE devid Device ID ee eedata EE Data 2005 Microchip Technology Inc DS33014J page 195 Assembler Linker Librarian User s Guide 13 4 44 C Source Code eeprom1 c eeproml c include p18f8720 h define DATA SIZE 0x1000 Data Table Setup pragma romdata DATTBL Put follow
176. device e g 18 452 1kr for the PIC18F452 device e Extended memory is specified e i Reserved memory for ICD resources is specified When including a standard linker script in your project itis recommended that you copy the file into your project folder This allows you to make changes to the linker script for that project if necessary without compromising the original file 2005 Microchip Technology Inc DS33014J page 181 Assembler Linker Librarian User s Guide 11 3 LINKER SCRIPT COMMAND LINE INFORMATION The MPLAB IDE Project Manager can set this information directly You probably only need to use these if you are linking from the command line LIBPATH LKRPATH FILES INCLUDE 1131 LIBPATH Library and object files which do not have a path are searched using the library object search path The following directive appends additional search directories to the 1ibrary object search path LIBPATH libpath where 1ibpathis a semicolon delimited list of directories EXAMPLE 11 1 LIBPATH EXAMPLE To append the current directory and the directory C PROJECTS INCLUDE to the library object search path the following line should be added to the linker command file LIBPATH C PROJECTS INCLUDE 11 3 2 LKRPATH Linker command files that are included using a linker script INCLUDE directive are searched for using the linker command file search path The following directive appends additional search directorie
177. dly code 0x1000 Page 2 Place Delay2 routine at program memory location 0x1000 on page 2 See Section 5 3 5 Program Memory CODE Sections and Paging for more on code This code was placed on a page other than 0 to demonstrate how a program functions across pages Delay2 movlw OxFF Set DTEMP value movwf DTEMP Ox00 shortest delay OXFF longest delay DLoop Use a simple countdown to decfsz DTEMP F Create delay goto DLoop End loop when DTEMP 0 return Use the time it takes to decrement a register DTEMP from an initial value to 0x00 as Delay 2 This method requires no timers or interrupts end End of the program i e tells the assembler no further code needs to be assembled 5 3 3 Header Files A header file is included in the program flow with the include directive include p16f877a inc Include header file Angle brackets quotes or nothing at all may used to enclose the name of the header file You may specify the complete path to the included file or let the assembler search for it For more on search order see the discussion of the include directive in Section 4 41 include Include Additional Source File A header file is extremely useful for specifying often used constants such as register and pin names This information can be typed in once and then the file can be included in any code using the processor with those registers and pins DS33014J page 128 O 2005 Microchip Technology Inc
178. drom Identify Unimplemented ROM eee 49 4 6 bankisel Generate Indirect Bank Selecting A AS I ora ee er A ne aNae 50 4 7 banksel Generate Bank Selecting Code sssssss 52 4 8 cblock Define a Block of Constants sseeR 54 4 9 code Begin an Object File Code Section occccccnnonoconcccnnnncononannnnnnnos 56 2005 Microchip Technology Inc DS33014J page iii Assembler Linker Librarian User s Guide 4 10 code pack Begin an Object File Packed Code Section APIS T8 MCUS A caco 57 4 11 config Set Processor Configuration Bits 0 00 eee eee 58 4 12 config Set Processor Configuration Bits PIC18 MCUs 59 4 13 constant Declare Symbol Constant ssssssses 60 4 14 da Store Strings in Program Memory PIC12 16 MCUS 61 4 15 data Create Numeric and Text Data sssssseee 62 4 16 db Declare Data of One Byte cocooooccccinocccccoconcccnononcncncnancncnnnnanaccnrnnnnncnno 65 4 17 de Declare EEPROM Data Byte ooooocccccoocccccnccoccccnononnccnnnnnnnnnonannnnnnnnnnnnn 67 4 18 define Define a Text Substitution Label ssssssss 68 4 19 dt Define Table PIC12 16 MCUS eese 70 4 20 dw Declare Data of One Word sse em 70 4 21 else Begin Alternative Assembly Block to if Conditional
179. ds 62 characters MPASM assembler has a 62 character limit on source file path names i e the length of the path plus the name of the file See Section 8 5 Assembler Limitations for more information 174 CONFIG directives must be listed in ascending order List config directive configuration registers in ascending order i e CONFIG CONFIGO CP OFF O0 CONFIG CONFIG1 _OSCS OFF 1 amp RCIO OSC 1 __ CONFIG _CONFIG2 BORON 2 BORV 25 2 175 IDLOCS directives must be listed in ascending order List idlocs directive ID registers in ascending order i e idlocs IDLOCO 0x1 idlocs IDLOC1 0x2 idlocs IDLOC2 0x3 176 CONFIG Directive Error An error was found in the config directive syntax 177 CONFIG directives cannot be used with CONFIG directives Do not mix config directives and config directives when assigning configuration bits in your code 178 CONFIG Directive Error An error was found in the __ config directive syntax UNKNOWN ERROR An internal application error has occurred is the value of the last defined error plus 1 Contact your Microchip Field Application Engineer FAE or Microchip support if you cannot debug this error 8 3 ASSEMBLER WARNINGS MPASM assembler warnings are listed numerically below 201 Symbol not previously defined The symbol being undefine d was not previously defined 202 Argument out of range Least significant bits used Argument d
180. e For information on types of code see Section 1 6 Assembler Operation There is no end code directive The code of a section ends automatically when another code or data section is defined or when the end of the file is reached 4 9 4 See Also extern code pack global idata udata udata acs udata ovr udata shr 4 9 5 Simple Example RESET code 0x01FF goto START 4 9 6 Application Example code This program demonstrates the code directive which declares the beginning of a section of program code include p16f877a inc Include standard header file for the selected device RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start 7 start DS33014J page 56 2005 Microchip Technology Inc Directives PGM CODE This is the begining of the code section named PGM It is a relocatable code section Since no absolute address is given along with directive CODE start clrw goto Go to current line loop here CODE This is a relocatable code nop Section since no address is Specified The section name will be by default code end 4 10 code pack BEGIN AN OBJECT FILE PACKED CODE SECTION PIC18 MCUs 4 10 1 Syntax 1abel code pack ROM address 4 10 2 Description This directive declares the beginning of a section of program code o
181. e instructions possibly interspersed with data The collection of all possible instructions for a particular processor is known as its instruction set Machine Language A set of instructions for a specific central processing unit designed to be usable by a processor without being translated Macro Macro instruction An instruction that represents a sequence of instructions in abbreviated form Macro Directives Directives that control the execution and data allocation within macro body definitions Make Project A command that rebuilds an application re compiling only those source files that have changed since the last complete compilation MCU Microcontroller Unit An abbreviation for microcontroller Also uC Message Text displayed to alert you to potential problems in language tool operation A message will not stop operation Microcontroller A highly integrated chip that contains a CPU RAM program memory I O ports and timers Microcontroller Mode One of the possible program memory configurations of PIC17 and PIC18 microcontrol lers In microcontroller mode only internal execution is allowed Thus only the on chip program memory is available in microcontroller mode DS33014J page 256 2005 Microchip Technology Inc Glossary Microprocessor Mode One ofthe possible program memory configurations of PIC17 and PIC18 microcontrol lers In microprocessor mode the on chip program memory is not used
182. e 187 Assembler Linker Librarian User s Guide 12 3 LINKER ALLOCATION ALGORITHM The linker allocates memory areas to allow maximum control over the location of code and data called sections in target memory There are four kinds of sections that the linker handles 1 Absolute Assigned 2 Absolute Unassigned 3 Relocatable Assigned 4 Relocatable Unassigned An absolute section is a section with a fixed absolute address that cannot be changed by the linker A relocatable section is a section that will be placed in memory based on the linker allocation algorithm An assigned section is a section that has been assigned a target memory block in the linker command file An unassigned section is a section that has been left unassigned in this file The linker performs allocation of absolute assigned and unassigned sections first relocatable assigned sections next and relocatable unassigned sections last The linker also handles stack allocation 12 3 1 Absolute Allocation Absolute sections may be assigned to target memory blocks in the linker command file But since the absolute section s address is fixed the linker can only verify that if there is an assigned target memory block for an absolute section the target memory block has enough space and the absolute section does not overlap other sections If no target memory block is assigned to an absolute section the linker tries to find the one for it If one can not be lo
183. e LIBRARY t List members Prints a table showing the names of the members in the LIBRARY x Extract member If MEMBER s exist in the LIBRARY then they are extracted If no MEMBER is specified all members will be extracted 16 4 COMMAND LINE EXAMPLES AND TIPS Example of Use Suppose you wanted to create a library named dsp 1ib from three object modules named t o fir o and iir o The following command line would produce the desired results mplib c dsp lib fft o fir o iir o To display the names of the object modules contained in a library file named dsp 1ib the following command line would be appropriate mplib t dsp lib Tips MPLIB librarian creates library files that may contain only a single external definition for any symbol Therefore if two object modules define the same external symbol the librarian will generate an error if both object modules are added to the same library file To minimize the code and data space which results from linking with a library file the library s member object modules should be as small as possible Creating object modules that contain only a single function can significantly reduce code space DS33014J page 232 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 17 Errors 17 1 INTRODUCTION MPLIB librarian detects the following sources of error and reports them Topics covered in this chapter Librarian Parse
184. e any length divisible by full words 16 bits The optional keyword PROTECTED indicates a region of memory that only can be used by program code that specifically requests it EXAMPLE 11 6 ROM EXAMPLE The program memory layout for a PIC16F877A microcontroller is shown below Memory Address Reset Vector 0000h 0003h Interrupt Vector 0004h User Memory Space 0005h 07FFh User Memory Space 0800h OFFFh User Memory Space 1000h 17FFh User Memory Space 1800h 1FFFh ID Locations 2000h 2003h Reserved 2004h 2005h Device ID 2006h Configuration Memory Space 2007h Reserved 2008h 20FFh EEPROM Data 2100h 21FFh Based on this map the CODEPAGE declarations are CODEPAGE NAME vectors START 0x0000 END 0x0004 PROTECTED CODEPAGE NAME page0 START 0x0005 END 0x07FF CODEPAGE NAME pagel START 0x0800 END 0x0FFF CODEPAGE NAME page2 START 0x1000 END 0x17FF CODEPAGE NAME page3 START 0x1800 END 0x1FFF CODEPAGE NAME idlocs START 0x2000 END 0x2003 PROTECTED CODEPAGE NAME config START 0x2007 END 0x2007 PROTECTED CODEPAGE NAME eedata START 0x2100 END 0x21FF PROTECTED 11 6 LOGICAL SECTION DEFINITION Logical sections are used to specify which of the defined memory regions should be used for a portion of source code To use logical sections define the section in the linker script file with the SECTION directive and then reference that nam
185. e e he ke echec ke che he ke e he ke kkk k k k get a hex byte in W convert to 2 ASCII bytes in ASCIIH ASCIIL req 2 stack levels i PRR RRR RRR KERR KERR ke e ke ke ke he ke he ke e he ke KKK ke e kkk RRR kkk e he ke kkk ke e he kk kkk kkk e KKK KKK EK Variables udata HexTemp res 1 ASCIIH res 1 ASCIIL res 1 PRR RRR RRR KERR KR he ke KKK KER he ke he ke e he ke KKK ke e he ke ke ce ke kkk ke e he k kkk ke e he k kkk k kkk e he ke KKK k k k code Hex2ASC movf HexTemp W andlw OxOF get low nibble call DecHex movwf ASCIIL swapf HexTemp F movf HexTemp W andlw OxOF get high nibble call DecHex movwf ASCIIH return PRR RRR RRR KERR KERR KKK ke ke he ke he ke e he ke ke e he ke e he ke ke ce ke ke he ke e he kkk ke e he kk kkk kkk e he ke ke e e k k k DecHex sublw 0x09 9 WREG btfss STATUS C is nibble Dec goto HexC no convert hex Dec movf HexTemp W convert DEC nibble to ASCII andlw OxOF addlw A 0 return HexC movf HexTemp W convert HEX nibble to ASCII andlw OxOF addlw A A 0x0A return H H W Jc AA lues ge og rci xr DS33014J page 138 2005 Microchip Technology Inc Assembler Examples Tips and Tricks PRR RRR RRR ck ke kc ke ke ee ke ke he ke he ke e ke ke KKK ke e he ke ke e ke ke e
186. e in the source file using that language s built in mechanism e g pragma section for MPLAB C18 The section directive defines a section by specifying its name and either the block of program memory in ROM or the block of data memory in RAM which contains the section SECTION NAME secName ROM memName RAM memName where secName is an ASCII string used to identify a section memName is a previously defined ACCESSBANK SHAREBANK DATABANK or CODEPAGE O 2005 Microchip Technology Inc DS33014J page 185 Assembler Linker Librarian User s Guide The ROM attribute must always refer to program memory previously defined using a CODEPAGE directive The RAM attribute must always refer to data memory previously defined with a ACCESSBANK DATABANK Or SHAREBANK directive EXAMPLE 11 7 LOGICAL SECTION DEFINITION To specify that a section whose name is filter coeffs be loaded into the region of program memory named constants the following line should be added to the linker command file SECTION NAME filter coeffs ROM constants EXAMPLE 11 8 LOGICAL SECTION USAGE To place MPASM source code into a section named filter coeffs use the following line prior to the desired source code filter coeffs CODE 11 7 STACK DEFINITION Only MPLAB C18 requires a software stack be set up The following statement specifies the stack size and an optional DATABANK where the stack is to be allocated STACK SIZE allocSize RAM memName
187. e instruction that was about to be executed when the interrupt occurred isr code 0x08 Interrupt Service Routine Servint banksel OPTION REG Select Option Reg Bank 1 bsf OPTION REG TOCS Stop TimerO banksel INTCON Select INTCON Bank 0 bcf INTCON TOIF Clear overflow flag bcf DFLAG DFLO Clear flag bit retfie Return from interrupt When the program code begins to execute again the cleared flag bit DFLO now causes the delay loop TLOOP to end thus ending Delay 1 routine 2005 Microchip Technology Inc DS33014J page 131 Assembler Linker Librarian User s Guide 5 4 EXAMPLE OF CALCULATIONS WITH VARIABLES AND CONSTANTS Directives highlighted in this example are define undefine set constant variable Items covered in this example are Program Functional Description Commented Code Listing Using Watch Windows 5 4 1 Program Functional Description This program performs several calculations using defined constants and variables The application is written as relocatable code i e you must use both the assembler and linker to generate the executable The standard header file for the processor selected is included using include Sections of code are created using the code statement 5 4 2 Commented Code Listing PRR RRR RRR KERR kc e ke AAA MPASM Assembler Control Directives Example Program 2 Perform calculations PRR RRR kkk kk kkk kkk kkk k he ke he ke
188. e k ke k e he ke e k kkk k include p16f877a inc Include header file Hdefine Tdistancel 50 Define the symbol Tdistancel Hdefine Tdistance2 25 Define the symbol Tdistance2 undefine Tdistance2 Remove Tdistance2 from the symbol table The define directive was used to define two substitution strings Tdistance1 to substitute for 50 and Tdistance2 to substitute for 25 Then undefine was used to remove Tdistance2 from the symbol table i e Tdistance2 can no longer be used to substitute for 25 udata 0x20 Set up distance reg distance reg res 1 at GPR 0x20 The udata and res directives are used to assign distance regto register 0x20 For more on these directives see example 1 rst code 0x00 Reset Vector pagesel Start goto Start code Start Program Start clrf distance_reg Clear register movlw Tdistancel Move value of Tdistancel _ aS SSA SS Qe AA DS33014J page 132 2005 Microchip Technology Inc Assembler Examples Tips and Tricks movwf distance reg into distance reg constant distancel 10 Declare distancel a constant symbol Declare a constant symbol distance1 with a value of 10 Once a constant is declared its value cannot be altered variable distance2 Declare distance2 a variable symbol Declare a variable symbol distance2 The variable directive does not require the symbol to be initialized when declared distance3 set 10 Define a value for the symbo
189. e source file For these situations two directives banksel 4 7 banksel Generate Bank Selecting Code and pagesel 4 52 pagesel Generate Page Selecting Code PIC10 12 16 MCUs have been added These directives instruct the linker to generate the correct bank or page selecting code for a specified label An example of how code should be converted is shown below EXAMPLE 6 8 BANKSEL AND PAGESEL Hard Coded Banking and Paging Use indirect addressing FSR and the STATUS register for banking and paging respectively include p12f509 inc Varl equ 0x10 Declare variables Var2 equ 0x30 movlw InitialValue bcf FSR 5 Data memory Varl bank 0 movwf Varl bsf FSR 5 Data memory Var2 bank 1 movwf Var2 bsf STATUS PAO Program memory page 1 call Subroutine Subroutine clrw On Page 1 retlw 0 BANKSEL for Banking and PAGESEL for Paging Use banksel and pagesel for banking and paging respectively include p12f509 inc extern Varl Var2 Declare variables code movlw InitialValue banksel Varl Select data memory Varl bank movwf Varl banksel Var2 Select data memory Var2 bank movwf Var2 pagesel Subroutine Select program memory page call Subroutine Subroutine clrw Page unknown at assembly time retlw 0 Sa c4 A ECC X A a H l 2005 Microchip Technology Inc DS33014J page 149 Assembler Linker Librarian User s Guide 6 9 GENERATING THE OBJECT MODULE Once the code co
190. eak and trace logic and to any sequential event in the Complex Trigger dialog PC Personal Computer or Program Counter PC Host Any IBM or compatible personal computer running a supported Windows operating system PlCmicro MCUs PICmicro microcontrollers MCUs refers to all Microchip microcontroller families PICSTART Plus A developmental device programmer from Microchip Programs 8 14 28 and 40 pin PlCmicro microcontrollers Must be used with MPLAB IDE Software Pod Emulator The external emulator box that contains emulation memory trace memory event and cycle timers and trace breakpoint logic Power on Reset Emulation A software randomization process that writes random values in data RAM areas to simulate uninitialized values in RAM upon initial power application PRO MATE Il A device programmer from Microchip Programs most PlCmicro microcontrollers as well as most memory and Keeloq devices Can be used with MPLAB IDE or stand alone Profile For MPLAB SIM simulator a summary listing of executed stimulus by register Program Counter The location that contains the address of the instruction that is currently executing Program Memory The memory area in a device where instructions are stored Also the memory in the emulator or simulator containing the downloaded target application firmware Project A set of source files and instructions to build the object and executable code for an application Proto
191. ect creation and setup Once the Project Wizard has completed the Project window should contain the project tree The workspace name is Example mocw the project name is Example mcp and all the project files are listed under their respective file type For more on workspaces and projects see MPLAB IDE documentation FIGURE 3 EXAMPLE PROJECT TREE CEN cn Example mcp E Source Files Example asm Example2 asm Header Files Object Files Library Files E Linker Scripts 16f84a lkr Other Files Set Build Options Select Project gt Build Options Project to open the Build Options dialog 1 Click on the MPASM Assembler tab For Categories General check that the Default Radix is set to Hexadecimal For Categories Output check that the Diagnostics level includes all errors warnings and messages Then check the checkbox for Generate cross reference file 2 Click on the MPLINK Linker tab For Categories All Options check that the Hex File Format is set to INHX32 Then check the checkbox for Generate map file 3 Click on the MPASM C17 C18 Suite tab For Categories All Options check that the Build normal target invoke MPLINK is selected 4 Click OK on the bottom of the dialog to accept the build options and close the dialog 5 Select Project gt Save Project to save the current configuration of the Example project 2005 Microchip Technology Inc DS33
192. ective is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation This directive saves you from having to manually code page bit changes Also since it automatically generates code the code is much more portable If you are using relocatable code and your device has more than 2k program memory or 0 5K for 12 bit instruction width devices it is recommended that you use this directive especially when code must jump between two or more code sections You must use this directive instead of pagese1 if you wish to indicate the start address of a RETLW table or a jump table for computed GOTOs Only then will all the 5 top most bits of the PC will be loaded with the appropriate value when an 8 bit offset is added to the PC The 256 word boundaries will still have to be considered as discussed in Application Note AN586 Macros for Page and Bank Switching 4 53 4 See Also bankisel banksel 4 53 5 Simple Example pageselw CommandTableStart Get the byte read and use it to movlw CommandTableStart index into our jump table If addwf Comm RxTxByte w we crossed a 256 byte boundary btfsc STATUS C then increment PCLATH Then load the incf PCLATH f program counter with computed goto movwf PCL CommandTableStart goto GetVersion 0x00 Get Version goto GetRTSample 0x01 Get Real Time sample goto Configure 0x02 stub goto Go 0x03 stub goto ReadBuffer 0x04 Read Buffe
193. ecursively The maximum number of nested macro calls is 16 Please refer to Chapter 7 Macro Language for more information 4 44 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation 4 44 4 See Also ENDM EXITM LOCAL 4 44 5 Simple Example Define macro Read Read macro device buffer count movlw device movwf ram 20 movlw buffer buffer address movwf ram 21 movlw count byte count call sys 21 Subroutine call endm Use macro Read Read 0x0 0x55 0x05 4 44 6 Application Example macro endm This code demonstrates the utility of macro directive which is used to define a macro Hinclude p16f877a inc Include standard header file for the selected device result equ 0x20 Assign value 20H to label result ORG 0x0000 The following code will be placed in reset address O0 goto start Jump to an address whose label is p starti add MACRO numi num2 add is a macro The values of numl and num2 must be passed to this macro DS33014J page 96 2005 Microchip Technology Inc Directives moviw numi Load W register with a literal value assigned to the label numl movwf result Load W register to an address location assigned to the label result movlw num2 Load W register with a literal value assigned to the label num2 addwf result Add W register with the me
194. ed devices 2005 Microchip Technology Inc DS33014J page 219 Assembler Linker Librarian User s Guide Unsupported relocation type A relocation type was specified that is not currently supported by the linker 14 4 LINKER WARNINGS MPLINK linker warnings are listed alphabetically below Fill pattern for memory nemName doesn t divide evenly into unused section locations Last value was truncated If a fill pattern is specified for a ROM section but the free space in that section isn t evenly divisible by the fill pattern size this warning will be issued to warn of incomplete patterns a command line option ignored with x x prevents the generation of a hex file Therefore specifying the format of hex output file with a is irrelevant n command line option ignored with w Aw prevents the generation of a cod file and a Ist file Therefore specifying the number of lines per listing page with n is irrelevant 14 5 LIBRARY FILE ERRORS MPLINK linker library file processing errors are listed alphabetically below Could not build member memberName in library file filename The file is not a valid library file or it is corrupted Could not open library file filename for reading Verify that filename exists and can be read Could not open library file filename for writing Verify that if filename exists it is not read only Could not write archive magic string in library file filename
195. ed from the Project gt Build Options dialog When using MPLINK linker in a batch file or directly from the command line the linker is invoked with the following syntax mplink cmdfiles objfiles libfiles options cmdfileis the name of a linker command file All linker command files must have the extension 1kr objfileisthe name of an assembler or compiler generated object file All object files must have the extension o libfileisthe name of a librarian created library file All library files must have the extension 1ib 2005 Microchip Technology Inc DS33014J page 179 Assembler Linker Librarian User s Guide optionis one of the linker command line options described below Option Description a hexformat Specify format of hex output file 1 78 Display help screen k pathlist Add directories to linker script search path 1 pathlist Add directories to library search path m filename Create map file filename n length Specify number of lines per listing page o filename Specify output file filename Default is a out q Quiet mode w Suppress mp2cod exe Using this option will prevent the generation of a cod file and a 1st file x Suppress mp2hex exe Using this option will prevent the generation of a hex file There is no required order for the command line arguments however changing the order can affect the operation of the linker Specifically additions
196. ed is other than 1200 2400 4800 9600 or 19200 Hz RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start Start PGM CODE This is the begining of the code section named PGM It is a relocatable code section since no absolute address is given along with directive CODE start goto Go to current line loop here end 2005 Microchip Technology Inc DS33014J page 75 Assembler Linker Librarian User s Guide 4 29 errorlevel SET MESSAGE LEVEL 4 29 1 Syntax errorlevel 0 1 2 msgnum msgnum 4 29 2 Description Sets the types of messages that are printed in the listing file and error file Setting Affect 0 Messages warnings and errors printed 1 Warnings and errors printed 2 Errors printed msgnum Inhibits printing of message msgnum msgnum Enables printing of message msgnum 4 29 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation Errors cannot be disabled Warnings may be disabled using setting 2 Messages may be disabled using settings 1 or 2 Also messages may be disabled individually However the setting of 0 1 or 2 overrides individual message disabling or enabling Be careful about disabling warnings an
197. ed when building the MPLAB C18 boot loader source code files The linker will use this configuration to link the compiled source code into the boot program memory region starting at 002Ah The vector locations will be specified in the boot loader source code using the appropriate pragma code directives Id 18 8722 1kr v 1 2 2004 09 13 22 07 05 curtiss Exp File 18 8722 1kr Sample linker script for the PIC18F8722 processor Modified 2005 02 02 for MPLAB C18 boot loader examples LIBPATH FILES c018i o FILES clib lib FILES p18f8722 1ib CODEPAGE NAME vectors START 0x0 END 0x29 PROTECTED CODEPAGE NAME boot START 0x2A END 0x7FF CODEPAGE NAME idlocs START 0x200000 END 0x200007 PROTECTED CODEPAGE NAME config START 0x300000 END 0x30000D PROTECTED CODEPAGE NAME devid START 0x3FFFFE END 0x3FFFFF PROTECTED CODEPAGE NAME eedata START 0xF00000 END 0xF003FF PROTECTED 13 5 4 MPLAB C18 Boot Loader Source Code The MPLAB C18 boot loader code can be composed of one or more aggregate relocatable C source files that are compiled and linked together during build time In this example the source code file uses the pragma code directive to instruct the linker to place the interrupt vectors at memory locations 0008h and 0018h A main function must be included as this is called from the MPLAB C18 startup code that is added during link process include lt p18cxxx h gt
198. em either name each section with its own name or move the code and data declarations such that each section is contiguous This error will also be generated if two sections of different types are given the same name 155 All overlaid sections of the same name must have the same starting address If multiple udata ovr sections with the same name are declared they must all have the same starting address 156 Operand must be an address label When generating object files only address labels in code or data sections may be declared global Variables declared by the set or equ directives may not be exported 2005 Microchip Technology Inc DS33014J page 161 Assembler Linker Librarian User s Guide 157 ORG at odd address For PIC18 devices you cannot place org at an odd address only even Consult your device data sheet 158 Cannot use RES directive with odd number of bytes For PIC18 devices you cannot use res to specify an odd number of bytes only even Consult your device data sheet 159 Cannot use FILL directive with odd number of bytes For PIC18 devices you cannot use 111 to fill with data an odd number of bytes only even Consult your device data sheet 160 CODE PACK directive not available for this part substituting CODE The code pack directive can only be used with byte addressable ROM 161 Non negative value required for this context Some contexts require non negative values 162 Expected a section name
199. emory you can Read Write on the target board that does not need refreshing frequently Status Bar The Status Bar is located on the bottom of the MPLAB IDE window and indicates such current information as cursor position development mode and device and active tool bar Step Into This command is the same as Single Step Step Into as opposed to Step Over follows a CALL instruction into a subroutine Step Over Step Over allows you to step over subroutines This command executes the code in the subroutine and then stops execution at the return address to the subroutine When stepping over a CALL instruction the next breakpoint will be set at the instruction after the CALL If for some reason the subroutine gets into an endless loop or does not return properly the next breakpoint will never be reached Select Halt to regain control of program execution Step Out Step Out allows you to step out of a subroutine which you are currently stepping through This command executes the rest of the code in the subroutine and then stops execution at the return address to the subroutine Stimulus Input to the simulator i e data generated to exercise the response of simulation to external signals Often the data is put into the form of a list of actions in a text file Stimulus may be asynchronous synchronous pin clocked and register Stopwatch A counter for measuring execution cycles 2005 Microchip Technology Inc DS33014J page
200. ences between relocatable and absolute code For more on these directives see Section 4 9 code Begin an Object File Code Section e Section 4 50 org Set Program Origin If no code directive is used code generation will begin at address zero For this example code is used to specify code at 0x00 Reset address 0x04 interrupt address 0x08 Interrupt Service Routine and 0x1000 Delay 2 address It does not explicitly set the program start address but allows the linker to place the code appropriately Since the linker places addressed code first and then attempts to place the relocatable code based on size the likely program memory usage is shown below 2005 Microchip Technology Inc DS33014J page 129 Assembler Linker Librarian User s Guide FIGURE 5 2 PIC16F877A PROGRAM MEMORY MAP rst 0x0000 intrpt 0x0004 Page0 lt m isr 0x0008 code Start 0x0010 S 0x0800 Page 1 lt See decdly Delay2 0x1000 Page 2 lt 4 0x1800 Page3 V OxlFFF Since the actual location of the main code code section is unknown pagesel directives must be used to ensure that program branches to other sections are correct rst code 0x00 Reset Vector pagesel Start goto Start code Start Program pagesel Delay2 Select Delay2 Page call Delay2 Wait pagesel Loop Select Loop Page goto Loop Repeat For more on this directive see Section 4 52 pagesel Gene
201. ended Reading The Microchip Web Site Development Systems Customer Change Notification Service Customer Support DOCUMENT LAYOUT This document describes how to use the MPASMTM assembler the MPLINKTM object linker and the MPLIB object librarian to develop code for PICmicro microcontroller MCU applications All of these tools can work within the MPLAB Integrated Development Environment IDE For a detailed discussion about basic MPLAB IDE functions refer to MPLAB IDE documentation PICmicro Language Tools Overview provides on overview of how to use all of the tools in this manual together under the MPLAB IDE This is how most developers will use these tools 2005 Microchip Technology Inc DS33014J page 1 Assembler Linker Librarian User s Guide MPASM Assembler Chapter 1 MPASM Assembler Overview describes what the MPASM assembler is what it does and how it works with other tools Chapter 2 Assembler Interfaces reviews how to use the MPASM assembler with MPLAB IDE and describes how to use the assembler on the command line in a command shell interface or in a Windows shell interface Chapter 3 Expression Syntax and Operation provides guidelines for using complex expressions in MPASM assembler source files Chapter 4 Directives lists each MPASM assembler directive alphabetically and describes the directive in detail with examples Chapter 5 Assembler Examples Tips and Tricks provid
202. ere please see Chapter 4 Directives Note Although MPASM assembler is often used with MPLINK object linker MPASM assembler directives are not supported in MPLINK linker scripts See MPLINK object linker documentation for more information on linker options to control listing and hex file output Topics covered are Example of Displaying Count on Ports Example of Port B Toggle and Delay Routines Example of Calculations with Variables and Constants Example of a 32 Bit Delay Routine Example of SPITM Emulated in Firmware Example of Hexadecimal to ASCII Conversion Other Sources of Examples Tips and Tricks 2005 Microchip Technology Inc DS33014J page 123 Assembler Linker Librarian User s Guide 5 2 EXAMPLE OF DISPLAYING COUNT ON PORTS Directives highlighted in this example are include end 5 2 1 Program Functional Description This simple program continually increases the count on PORTA and PORTB This count may be displayed in software in the SFR or watch window of MPLAB IDE or in hardware on connected LEDs or a scope The count may be slowed down using a delay routine see other examples Once the count has increased to OxFF it will roll over to 0x00 and begin again The application is written as absolute code i e you use only the assembler to generate the executable not the assembler and linker The standard header file for the processor selected is included using include The port out
203. es e g ifdef while Arguments may be used anywhere within the body of the macro except as part of normal expression The exitm directive provides an alternate method for terminating a macro expansion During a macro expansion this directive causes expansion of the current macro to stop and all code between the exitm and the endm directives for this macro to be ignored If macros are nested exitm causes code generation to return to the previous level of macro expansion 7 5 MACRO INVOCATION Once the macro has been defined it can be invoked at any point within the source module by using a macro call as described below macro name arg arg where macro name is the name of a previously defined macro and arguments are supplied as required The macro call itself will not occupy any locations in memory However the macro expansion will begin at the current memory location Commas may be used to reserve an argument position In this case the argument will be an empty string The argument list is terminated by white space or a semicolon DS33014J page 154 2005 Microchip Technology Inc Macro Language EXAMPLE 7 1 The following macro define table macro local a 0 while a 3 entrytv a dw a 1 endw endm When invoked would generate entry0 entryl entry2 entry3 dw dw dw dw ooo 7 6 MACRO CODE EXAMPLES The following are examples of macros Literal to RAM Co
204. es examples of how to use the MPASM assembler directives together in applications Chapter 6 Relocatable Objects describes how to use the MPASM assembler in conjunction with MPLINK object linker Chapter 7 Macro Language describes how to use the MPASM assembler s built in macro processor Chapter 8 Errors Warnings Messages and Limitations contains a descriptive list of the errors warnings and messages generated by the MPASM assembler as well as tool limitations MPLINK Object Linker Chapter 9 MPLINK Linker Overview describes what the MPLINK object linker is what it does and how it works with other tools Chapter 10 Linker Interfaces reviews how to use the MPLINK linker with MPLAB IDE and describes how to use the linker on the command line Chapter 11 Linker Scripts discusses how to generate and use linker scripts to control linker operation Chapter 12 Linker Processing describes how the linker processes files Chapter 13 Sample Applications provides examples of how to use the linker to create applications Sample Application 1 explains how to find and use template files and how to modify the linker script file Sample Application 2 explains how to place program code in different memory regions how to place data tables in ROM memory and how to set configuration bits in C Sample Application 3 explains how to partition memory for a boot loader and how to compile code that
205. es microchip mpasm suite lkr switch requires lt pathlist gt A semicolon delimited path must be specified Enclose directory names containing embedded spaces with double quotes For example 1 c mylib c program files microchip mpasm suite m switch requires lt filename gt A map filename must be specified For example m main map Multiple inclusion of library file filename A library file has been included multiple times either on the command line or with a FILES directive in a linker command file Remove the multiple references Multiple inclusion of linker command file cmdfile A linker command file can only be included once Remove multiple INCLUDE directives to the referenced linker command file Multiple inclusion of object file filename An object file has been included multiple times either on the command line or with a FILES directive in a linker command file Remove the multiple references n switch requires lt length gt The number of source lines per listing file page must be specified A length of zero will suppress pagination of the listing file o switch requires lt filename gt A COFF output filename must be specified For example o main out Unknown switch cmdline token An unrecognized command line switch was supplied Refer to the Usage documentation for the list of supported switches Unrecognized input in cmdfile line All statements in a linker command fi
206. essor superseded by command line Verify processor symbol The processor was specified on the command line as well as in the source file The command line has precedence If you are using MPLAB IDE with the assembly set the device to match the source file from Configure gt Select Device 216 Radix superseded by command line The radix was specified on the command line as well as in the source file The command line has precedence 217 Hex file format specified on command line The hex file format was specified on the command line as well as in the source file The command line has precedence DS33014J page 164 2005 Microchip Technology Inc Errors Warnings Messages and Limitations 218 Expected DEC OCT HEX Will use HEX Bad radix specification 219 Invalid RAM location specified Ifthe maxramand badramdirectives are used this warning flags use of any RAM locations declared as invalid by these directives Note that the provided header files include maxramand _ badram for each processor 220 Address exceeds maximum range for this processor A ROM location was specified that exceeds the processor s memory size 221 Invalid message number The message number specified for displaying or hiding is not a valid message number 222 Error messages cannot be disabled Error messages cannot be disabled with the errorlevel command 223 Redefining processor The selected processor is being reselected by the 1i
207. estination select bit d 0 store result in WREG d 1 store result in file register f default i Table pointer control i 2 0 do not change i 1 increment after instruction execution S Destination select bit S 0 store result in file register f and WREG S 1 store result in file register f default t Table byte select t 0 perform operation on lower byte t 1 perform operation on upper byte ES Bit values as opposed to Hex value Named Registers BSR Bank Select Register Used to select the current RAM bank OPTION OPTION Register PCL Program Counter Low Byte PCH Program Counter High Byte PCLATH Program Counter High Byte Latch PCLATU Program Counter Upper Byte Latch PRODH Product of Multiply High Byte PRODL Product of Multiply Low Byte TBLATH Table Latch TBLAT High Byte TBLATL Table Latch TBLAT Low Byte TBLPTR 16 bit Table Pointer TBLPTRH TBLPTRL Points to a Program Memory location WREG Working register accumulator Named Bits C DC Z OV N ALU Status bits Carry Digit Carry Zero Overflow Negative TO Time out bit PD Power down bit GIE Global Interrupt Enable bit s Named Device Features PC Program Counter TOS Top of Stack WDT Watchdog Timer Misc Descriptors Contents gt Assigned to lt gt Register bit field EEE a N DS33014J page 238 2005 Microchip Technology Inc Instruction Sets
208. expressions Should there be an odd number of expressions the last byte will be zero unless in a PIC18 code pack section 4 16 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation When generating a linkable object file this directive can also be used to declare initialized data values Refer to the idata directive for more information For PIC18 devices use code pack with db since it is desired to not have bytes padded with zeroes See the description of code pack for more information 4 16 4 See Also data de dt dw idata code pack 4 16 5 Simple Examples Example1 PIC16 Devices db OxOf t OxOf e OxOf s OxOf t n ASCII 0x0F74 OxOF65 0x0F73 0x0F74 0x0a00 Example 2 PIC18 Devices db bh MEN Verso beh ot Nn ASCII 0x6574 0x7473 0x000a 4 16 6 PIC16 Application Example db This example shows the usefulness of directive db in storing one or more bytes or characters in program memory include p16f877a inc Include standard header file for the selected device ORG 0x0000 The following code will be programmed in reset address 0 goto start Jump to an address labelled start start Write your main program here goto Go to current line loop here ORG 0x1000 Store the string starting from 1000H Ch stng db 0 M 0 C 0 U 2005 Microchip Technology Inc DS33014J page
209. extended microcontroller mode on chip program memory as well as external mem ory is available Execution automatically switches to external if the program memory address is greater than the internal memory space of the PIC17 or PIC18 device External Label A label that has external linkage External Linkage A function or variable has external linkage if it can be referenced from outside the module in which it is defined nr 2005 Microchip Technology Inc DS33014J page 253 Assembler Linker Librarian User s Guide External Symbol A symbol for an identifier which has external linkage This may be a reference or a definition External Symbol Resolution A process performed by the linker in which external symbol definitions from all input modules are collected in an attempt to resolve all external symbol references Any external symbol references which do not have a corresponding definition cause a linker error to be reported External Input Line An external input signal logic probe line TRIGIN for setting an event based upon external signals External RAM Off chip Read Write memory File Registers On chip data memory including General Purpose Registers GPRs and Special Function Registers SFRs Filter Determine by selection what data is included excluded in a trace display or data file Flash A type of EEPROM where data is written or erased in blocks instead of bytes FNOP Forced No Operation A forced N
210. extended mode see the MPLAB C18 C Compiler User s Guide DS51288 and your device data sheet Instruction opcode is shown in hex by making certain assumptions either listed in the key or as a footnote For more information on the opcode bit values for each instruction as well as the number of cycles per instruction Status bits affected and complete instruction details see the relevant device data sheet TABLE A 13 PIC18 EXTENDED INSTRUCTIONS Hex Mnemonic Description Function E8fk ADDFSR k Add literal to FSR FSR f k gt FSR f E8Ck ADDULNK k Add literal to FSR2 and return FSR2 k 2 FSR2 TOS 2 PC 0014 CALLW Call subroutine using WREG PC 2 gt TOS W gt PCL PCLATH gt PCH PCLATU gt PCU EB O z MOVSF z f Move z source to 1st word FSR2 z gt f Ffff f destination 2nd word EB 1 z MOVSS z z Move Z source to 1st word FSR2 z gt FSR2 z FXZZ z destination 2nd word EAkk PUSHL k Store literal at FSR2 k gt FSR2 decrement FSR2 FSR2 1 FSR2 E9fk SUBFSR f k Subtract literal from FSR FSR f k FSR f E9Ck SUBULNK k Subtract literal from FSR2 and return FSR2 k gt FSR2 TOS 2 PC DS33014J page 248 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Appendix B Useful Tables B 1 INTRODUCTION Some useful tables are included for reference here The tables are AS
211. field A 7 PIC18 DEVICE INSTRUCTION SET Microchip s new high performance 8 bit microcontroller family uses a 16 bit wide instruction set This instruction set consists of 76 instructions each a single 16 bit wide word 2 bytes Most instructions operate on a file register f and the working register WREG accumulator The result can be directed either to the file register or the WREG register or to both in the case of some instructions A few instructions operate solely on a file register BSF for example The instruction set is grouped into the following categories byte oriented file register operations bit oriented file register operations control operations literal operations and memory operations Additionally extended mode instructions are shown in Section A 8 PIC18 Device Extended Instruction Set Instruction opcode is show in hex by making certain assumptions either listed in the key or as a footnote For more information on the opcode bit values for each instruction as well as the number of cycles per instruction Status bits affected and complete instruction details see the relevant device data sheet TABLE A 8 PIC18 BYTE ORIENTED REGISTER OPERATIONS Hex Mnemonic Description Function 27 ADDWF f d a ADD WREG tof WREG f gt dest 23f ADDWFC d a ADD WREG and Carry bit to f WREG f C gt dest 17 ANDWF f d a AND WREG with f WREG AND f gt dest 6Bf CLRF f a Clear f 0f DS33014J page 2
212. file for the selected device GLOBAL delay The variable delay declared GLOBAL in this module is included in an EXTERN directive in the module main asm 2005 Microchip Technology Inc DS33014J page 81 Assembler Linker Librarian User s Guide EXTERN delay value The variable delay value declared EXTERN in this module is declared GLOBAL in the module main asm PGM CODE delay decfsz delay value 1 goto delay return end 4 33 fill SPECIFY PROGRAM MEMORY FILL VALUE 4 33 1 Syntax label fill expr count 4 33 2 Description Generates count occurrences of the program word or byte PIC18 devices expr If bounded by parentheses expr can be an assembler instruction 4 33 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is often used to force known data into unused program memory This helps ensure that if code ever branches to an unused area at run time a fail safe condition occurs For example it is not uncommon to see this used with the watchdog timer WDT on a PIC16 device Unused program memory would be filled with goto or branch instructions to prevent execution of the clrwdt instruction in code which would cause the device to reset See the device data sheet for more information on the WDT 4 33 4 See Also data dw org 4 33 5 Simple Examples Example 1 PIC10 12
213. file has the following format The symbols are listed in the Label column sorted by name The Type column defines the type of symbol A list of Label Types is provided at the end of the file The File Name column lists the names of the files that use the symbol The Source File References column lists the line number of the corresponding file in the File Name column where the symbol is defined referenced An asterisk means a definition To prevent cross reference file generation use the x option 1 7 7 Symbol and Debug File cod A COD file is used by MPLAB IDE to debug absolute assembly code For absolute code generation the MPASM assembler produces a cod file for debugging For relocatable code generation the MPASM assembler and the MPLINK linker are used together and the linker produces both a coa and a coff file for debugging Note The COD file name including the path has a 62 character limit The COFF file does not have this limitation To suppress COD file generation when using the linker either use the w option on the command line select Suppress COD file generation on the MPLINK Linker tab of the Build Options dialog Project gt Build Options gt Project in MPLAB IDE 1 7 8 Object File 0 The assembler creates a relocatable object file from source code This object file does not yet have addresses resolved and must be linked before it can be used as an executable
214. fo Coff file filename could not write optional file header Coff file filename could not write raw data Coff file filename could not write reloc Coff file filename could not write section header Coff file filename could not write string Coff file filename could not write string table length Coff file filename could not write symbol Coff file filename cScnHdr size cScnNum size Coff file filename does not appear to be a valid COFF file Coff file filename has relocation entries but an empty symbol table Coff file filename missing optional file header Coff file filename section xx has an invalid s offset Coff file filename section secName line xx has an invalid fcnndx Coff file filename section secName line xx has an invalid srcndx Coff file filename section secName reloc xx has an invalid r_symndx Coff file filename symbol xx has an invalid n offset Coff file filename symbol xx has an invalid n scnum Coff file filename symbol xx has an invalid index Could not find section name secName in string table Could not find symbol name symName in string table Could not open Coff file filename for reading Could not open Coff file filename for writing Could not read archive magic string in library file filename Unable to find aux file name in string table Unable to find se
215. from assembling i e itis a warning not an error 8 4 ASSEMBLER MESSAGES MPASM assembler messages are listed numerically below 301 MESSAGE User definable message invoked with the messg directive see Section 4 47 messg Create User Defined Message 302 Register in operand not in bank 0 Ensure that bank bits are correct This is a commonly seen reminder message to tell you that a variable that is being accessed in not in bank 0 This message was added to remind you to check your code particularly code in banks other than 0 Review the section on banksel Section 4 7 banksel Generate Bank Selecting Code and bankisel Section 4 6 bankisel Generate Indirect Bank Selecting Code PIC12 16 MCUs and ensure that your code uses bank bits whenever changing from ANY bank to ANY other bank including bank 0 Since the assembler or linker can t tell which path your code will take you will always get this message for any variable not in bank 0 You can use the errorlevel command to turn this and other messages on and off but be careful as you may not spot a banking problem with this message turned off For more about errorlevel see Section 4 29 errorlevel Set Message Level A similar message is 306 for paging 303 Program word too large Truncated to core size The program word instruction width is too large for the selected device s core program memory size Therefore the word has been truncate
216. g either MPASM assembler s CONFIG directive or MPLAB C18 s pragma config directive Multiple map files declared filename1 filename2 The m lt mapfile gt switch was specified more than once Multiple output files declared filename filename2 The o outfile switch was specified more than once Multiple STACK definitions A STACK directive occurs more than once in the linker command file or included linker command files Remove the multiple STACK directives No input object files specified No input object or library file was specified to the linker Enter files to link Overlapping definitions of SHAREBANK memName A SHAREBANK directive specifies a range of addresses that overlap a previous definition Overlaps are not permitted DS33014J page 216 2005 Microchip Technology Inc Errors Warnings and Common Problems PCL TOSH TOSU TOSL cannot be used as the destination of a MOVFF or MOVSF instruction The MOVFF instruction has unpredictable results when its destination is the PCL TOSH TOSU or TOSL registers MPLINK will not allow the destination of a MOVFF instruction to be replaced with any of these addresses Processor types do not agree across all input files Each object module and library file specifies a processor type or a processor family All input modules processor types or families must match Section absolute access overlay share types for secName do not match across i
217. gram memory To create a four cycle delay add a label to an existing RETURN instruction in the code In this example the label Rt rn was added to the RETURN of subroutine that already existed somewhere in the code When executing CALL Rtrn the MCU delays two instruction cycles to execute the CALL and two more to execute the RETURN Instead of using four NOP instructions to create a four cycle delay the same result was achieved by adding a single CALL instruction 5 9 2 TIP 2 Optimizing Destinations Destination bit determines w or F for result Look at data movement and restructure Example B A MOVF A W MOVF B W ADDWF B W ADDWF A F MOVWF A 3 instructions 2 instructions Careful use of the destination bits in instructions can save program memory Here register A and register B are summed and the result is put into the A register A destination option is available for logic and arithmetic operations In the first example the result of the ADDWF instruction is placed in the working register A MOvWF instruction is used to move the result from the working register to register A In the second example the ADDWF instruction uses the destination bit to place the result into the A register saving an instruction 5 9 3 TIP 3 Conditional Bit Set Clear To move single bit of data from REGA to REGB Precondition REGB bit Test REGA bit and fix REGB if necessary BTFSS REGA 2 BCF REGB 5 BCF REGB 5 BTFSC REGA 2 BTFSC R
218. gt gt f lt b gt Assuming b 0 and default bit value for a Assuming default bit value for s TABLE A 10 PIC18 CONTROL OPERATIONS Hex Mnemonic Description Function E2n BC n Branch if Carry if C 1 PC 2 2 n PC else PC 2 PC E6n BN n Branch if Negative fN 1 PC 2 2 n PC else PC 2 PC E3n BNC n Branch if Not Carry fC 0 PC 2 2 n PC else PC 2 PC E7n BNN n Branch if Not Negative if N 0 PC 2 2 n PC else PC 2 PC E5n BNOV n Branch if Not Overflow if OV 0 PC 2 2 n PC else PC 2 gt PC Eln BNZ n Branch if Not Zero fZ 0 PC 2 2 n PC else PC 2 gt PC E4n BOV n Branch if Overflow fOV 1 PC 2 2 n PC else PC 2 gt PC D O n BRA n Branch Unconditionally PC 2 2 n gt PC EOn BZ n Branch if Zero if Z 1 PC 2 2 n PC else PC 2 gt PC ECkk CALL n s Call Subroutine 1st word PC 4 TOS n gt PC lt 20 1 gt Fkkk 2nd word ifs 21 WREG WREGs STATUS gt STATUSs BSR gt BSRs 0004 CLRWDT Clear Watchdog Timer 0 gt WDT 0 gt WDT postscaler 1o TO 1 PD 0007 DAW Decimal Adjust WREG if WREG lt 3 0 gt gt 9 or DC 1 WREG lt 3 0 gt 6 WREG lt 3 0 gt else WREG lt 3 0 gt gt WREG lt 3 0 gt if WREG 7 4 gt 9 or C 1 WREG lt 7 4 gt 6 gt WREG lt 7 4 gt else WREG lt 7 4 gt gt WREG lt 7 4 gt EFkk GOTO n Go to address 1st word n PC lt 20 1 gt Fkkk 2nd word 0000 NOP N
219. haracter Set i ssa nuce a 249 B 3 Hexadecimal to Decimal Conversion eeem 250 GIOS SONY RN TTE TRITT I T 251 o qmd 265 Worldwide Sales and Service 11 11 1leeee eee eeeeeee eene n nennen nnn n nanus nana nn 270 DS33014J page viii 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Preface NOTICE TO CUSTOMERS All documentation becomes dated and this manual is no exception Microchip tools and documentation are constantly evolving to meet customer needs so some actual dialogs and or tool descriptions may differ from those in this document Please refer to our web site www microchip com to obtain the latest documentation available Documents are identified with a DS number This number is located on the bottom of each page in front of the page number The numbering convention for the DS number is DSXXXXXA where XXXXX is the document number and A is the revision level of the document For the most up to date information on development tools see the MPLAB IDE on line help Select the Help menu and then Topics to open a list of available on line help files INTRODUCTION This chapter contains general information that will be useful to know before using Assembler Linker Librarian User s Guide Items discussed include Document Layout Conventions Used Recomm
220. he instruction encoding cannot reference addresses that are not word aligned symbol symName out of range of relative branch instruction A relative branch instruction had symName as its target but a 2 s complement encoding of the offset to symName wouldn t fit in the limited number of instruction bits used for the target of a branch instruction DS33014J page 218 2005 Microchip Technology Inc Errors Warnings and Common Problems The CONFIG DECL macro can only be specified in one module Found in foo o previously found in bar o This error is issued when MPLAB C18 s CONFIG DECL macro is specified in two separate c files e g foo c and bar c Set configuration bits by using the _CONFIG_DECL macro in only one c file The CONFIG DECL macro found in foo o cannot be used with MPASM s _ CONFIG directive found in bar o This error is issued when MPLAB C18 s CONFIG DECL macro is used in a c file e g oo c and MPASM assembler s _ CONFIG directive is used ina asm file e g bar asm Set configuration bits using either the CONFIG DECL macro from MPLAB C18 or the CONFIG directive in MPASM assembler The CONFIG DECL macro found in foo o cannot be used with either MPLAB C18 s Zpragma config directive or MPASM s CONFIG directive found in bar o This error is issued when MPLAB C18 s CONFIG DECL macro is used in a c file e g foo c with either MPLAB C18 s pragma config directive in a second
221. he drop down list Under Code Model click Large code mode gt 64K For the command line use the m1 option when compiling The linker script file for this sample application is a modification of the standard linker file for the device 13 6 6 MPASM Assembler Usage In an MPASM application s source file using a simple define or equ directive provides an easy way to define the SRAM starting address which can be used to set up the table pointers prior to a table read or table write operation define SRAM BASE ADDRS 0x20000 Base addrs for external memory device define SRAM END ADDRS OxlFFFFF End addrs not required Accessing the external program memory through table reads and table writes requires the table pointer register be set up with the appropriate address as shown by the following example DS33014J page 210 2005 Microchip Technology Inc Sample Applications movlw upper SRAM BASE ADDRS movwf TBLPTRU movlw high SRAM BASE ADDRS movwf TBLPTRH movlw low SRAM BASE ADDRS movwf TBLPTRL 13 6 7 MPASM Assembler Memory Map The figure below shows the memory mapping for the PIC18F8722 when used with the 1Mbyte external SRAM device Notice that the first 128K bytes of the external memory region is overlapped with the 128K bytes of internal program memory space and therefore cannot be accessed using the external memory bus Without any additional external memory address decoding the first
222. he top of each page The first column contains the base address in memory where the code will be placed The second column is reserved for the machine instruction This is the code that will be executed by the PICmicro MCU The third column displays disassembly code The fourth column lists the associated source code line The fifth column lists the file associated for the source code line Note Due to page width restrictions some comments have been shortened indi cated by Also associated file names have been replaced by numbers i e 1 and 2 See the end of the listing of the actual file paths and names COFF to COD File Converter Copyright c 2004 Microchip Technology Inc Listing File Generated Tue Nov 02 14 33 23 2004 Addres 000000 000002 00002c 00002e 000030 000032 000034 S Value ef16 000 0e0a 6 80 9780 ef16 000 Disassembly Source File include p18f452 inc 1 LIST 2 P18F452 INC Standard Header File 2 LIST 2 udata 1 Dest res 1 1 1 RST code 0x0 1 GOTO Ox2c goto Start 1 1 PGM code 1 MOVLW Oxa Start movlw Ox0A 1 MOVWF 0x80 0x1 movwf Dest 1 BCF 0x80 0x3 0x1 bcf Dest 3 1 GOTO Ox2c goto Start 1 end 1 where D Projects32 PIC18F452 SourceReloc asm C Program Files Microchip MPASM Suite p18f452 inc SR 2005 Microchip Technology Inc DS33014J page 175 Assembler Linker Librarian User s Guide 9 7 8 Map File map The map file ge
223. he trace buffer captures the information that is on the bus at one instance Therefore one trace buffer entry will contain execution information for three instructions The number of cap tured cycles from one piece of information to another for a single instruction execution is referred to as the skew DS33014J page 260 2005 Microchip Technology Inc Glossary Skid When a hardware breakpoint is used to halt the processor one or more additional instructions may be executed before the processor halts The number of extra instructions executed after the intended breakpoint is referred to as the skid Source Code The form in which a computer program is written by the programmer Source code is written in some formal programming language which can be translated into or machine code or executed by an interpreter Source File An ASCII text file containing source code Special Function Registers The portion of data memory RAM dedicated to registers that control I O processor functions I O status timers or other modes or peripherals Stack Hardware Locations in PICmicro microcontroller where the return address is stored when a function call is made Stack Software Memory used by an application for storing return addresses function parameters and local variables This memory is typically managed by the compiler when developing code in a high level language Static RAM or SRAM Static Random Access Memory Program m
224. ical support requests online discussion groups Microchip consultant program member listing Business of Microchip Product selector and ordering guides latest Microchip press releases listing of seminars and events listings of Microchip sales offices distributors and factory representatives DEVELOPMENT SYSTEMS CUSTOMER CHANGE NOTIFICATION SERVICE Microchip s customer notification service helps keep customers current on Microchip products Subscribers will receive e mail notification whenever there are changes updates revisions or errata related to a specified product family or development tool of interest To register access the Microchip web site at www microchip com click on Customer Change Notification and follow the registration instructions The Development Systems product group categories are Compilers The latest information on Microchip C compilers and other language tools These include the MPLAB C18 and MPLAB C30 C compilers MPASM and MPLAB ASM30 assemblers MPLINK and MPLAB LINK30 object linkers and MPLIB and MPLAB LIB30 object librarians Emulators The latest information on Microchip in circuit emulators This includes the MPLAB ICE 2000 and MPLAB ICE 4000 In Circuit Debuggers The latest information on the Microchip in circuit debugger MPLAB ICD 2 MPLAB IDE The latest information on Microchip MPLAB IDE the Windows9 Integrated Development Environment for development systems tools This li
225. ices The operation of these PICmicro MCU language tools with MPLAB IDE is discussed here Topics covered in this chapter MPLAB IDE and Tools Installation MPLAB IDE Setup MPLAB IDE Projects Project Setup Project Example MPLAB IDE AND TOOLS INSTALLATION In order to use the PICmicro MCU language tools with MPLAB IDE you must first install MPLAB IDE The latest version of this free software is available at our website http www microchip com or from any sales office back cover When you install MPLAB IDE you will be installing the MPASM assembler the MPLINK object linker and the MPLIB object librarian as well By default the language tools will be installed in the directory C Program Files Microchip MPASM Suite The executables for each tool will be in this directory MPASM Assembler mpasmwin exe MPLINK Object Linker mplink exe MPLIB Object Librarian mplib exe All device include header files are also in this directory For more on these files see MPASM assembler documentation All device linker script files are in the LKR subdirectory For more on these files see MPLINK object linker documentation Code examples and template files are also included in subdirectories for your use Template files are provided for absolute code Code and relocatable code Object development 2005 Microchip Technology Inc DS33014J page 9 Assembler Linker Librarian User s Guide MPLAB IDE SETUP
226. icrochip Technology Inc Assembler Interfaces 2 5 COMMAND LINE INTERFACE MPASM assembler can be invoked through the command line interface command prompt as follows mpasmwin option1 optionN filename Or mpasm option1 optionN filename where option refers to one of the command line options filename is the file being assembled For example if test asm exists in the current directory it can be assembled with following command mpasmwin e 1 test asm If the source filename is omitted the appropriate shell interface is invoked i e mpasmwin a Windows interface is displayed which includes a Help button mpasm an interactive text interface is displayed same as mpasm Option Default Description N A Display the assembler help screen mpasm exe only ahex format INHX32 Generate absolute cod and hex output directly from assembler where hex format is one of INHX8M INHX8S INHX32 See 1 7 5 Hex File Formats hex hxl hxh for more information c On Enable Disable case sensitivity If enabled the assembler will distinguish between uppercase and lowercase letters dlabel value N A Define a text string substitution i e assign value to label el path On Enable Disable Set Path for error file e Enable e Enable e Disable e path Enable specify path See Section 1 7 4 Error File err for more information h N A Display the a
227. id not fit in the allocated space For example literals must be 8 bits 203 Found opcode in column 1 An opcode was found in column one which is reserved for labels 2005 Microchip Technology Inc DS33014J page 163 Assembler Linker Librarian User s Guide 204 Found pseudo op in column 1 A pseudo op was found in column one which is reserved for labels 205 Found directive in column 1 A directive was found in column one which is reserved for labels 206 Found call to macro in column 1 A macro call was found in column one which is reserved for labels 207 Found label after column 1 A label was found after column one which is often due to a misspelled opcode 208 Label truncated at 32 characters Maximum label length is 32 characters 209 Missing quote A text string or character was missing a quote For example DATA a 210 Extra An extra comma was found at the end of the line 211 Extraneous arguments on the line Extra arguments were found on the line 212 Expected ENDIF Expected an endif statement i e an if statement was used without an endi f 213 The EXTERN directive should only be used when making a o file The extern directive only has meaning if an object file is being created This warning has been superseded by Error 149 214 Unmatched An unmatched parenthesis was found The warning is used if the parenthesis is not used for indicating order of evaluation 215 Proc
228. ied in the sample application Select either the Microchip MPASM Toolsuite or the Microchip C18 Toolsuite as the active toolsuite Make sure the executable paths are correct Name the project and place it in its own folder Add the sample files to your project e g sourcel c source2 asm and script lkr If they are not already in the project folder check the checkbox next to each file to copy it into the folder 2005 Microchip Technology Inc DS33014J page 191 Assembler Linker Librarian User s Guide 2 Once the project is created select Project Build Options Project to open the Build Options for Project dialog For MPLAB C18 sample applications click the General tab and enter c mcc18 lib under Library Path Click the MPLINK Linker tab and then click the Generate map file checkbox to select it 3 Select Project gt Build All to build the application 4 Ifthe application fails to build check that the environment variables discussed in the next section were set correctly during tool installation 13 2 2 Using the Command Line To build an application on the command line 1 The listed Environment Variables need to be set as specified To set these vari ables go to the Command prompt and type SET to view and set the variables In Windows OS go to Start Settings Control Panel System Advanced tab Environment Variables button View and edit variables here PATH Make sure the following
229. ifier symbols have their final addresses assigned the linker must patch all references to these symbols using the relocation entries In the example above the updated symbol might now be at location 0x125 Symbol index gt name varl value 0x125 section data class extern If the code section above were relocated to begin at address 0x50 the updated relocation entries would now begin at location 0x51 Reloc index gt address 0x0051 symbol varl type bank Reloc index gt address 0x0052 symbol varl type offset The linker will step through the relocation entries and patch their corresponding sections The final assembly equivalent output for the above example would be 0x0050 MOVLW OxFF 0x0051 MOVLR 0x1 Patched with varl s bank 0x0052 MOVWF 0x25 Patched with varl s offset 2005 Microchip Technology Inc DS33014J page 189 Assembler Linker Librarian User s Guide 12 5 INITIALIZED DATA MPLINK linker performs special processing for input sections with initialized data Initialized data sections contain initial values initializers for the variables and constants defined within them Because the variables and constants within an initialized data section reside in RAM their data must be stored in nonvolatile program memory ROM For each initialized data section the linker creates a section in program memory The data is moved by initializing code supplied with MPLAB C18 and MPASM assembler to the proper RAM location
230. iled each time a change is made in your code compilation time may be reduced 9 5 LINKER PLATFORMS SUPPORTED MPLINK linker is distributed as a Windows 32 console application suitable for Windows 95 98 and Windows NT 2000 XP platforms 9 6 LINKER OPERATION Below is a diagram of how the MPLINK linker works with other Microchip tools main c prog asm source files Y Y MPLAB C18 MPASM assembler Y Y main o prog o object files AER TTE library files NM 18c452 1kr linker script files pus t M prog cof prog hex prog map output files prog cod prog lst The MPLINK linker combines multiple input object modules generated by the MPASM assembler or MPLAB C18 C compiler into a single output executable hex file A linker script tells the linker how to combine these modules DS33014J page 172 2005 Microchip Technology Inc MPLINK Linker Overview The linker is executed after assembling or compiling relocatable object modules with the MPASM assembler and or MPLAB C18 C compiler The actual addresses of data and the location of functions will be assigned when the MPLINK linker is executed This means that you may instruct the linker via a linker script to place code and data somewhere within named regions of memory or if not specified to place into any available memory The linker script must also tell the MPLINK linker about the ROM and RAM memory regions available in the target PICmicro MCU device Then
231. illegal digit in a number Valid digits are 0 1 for binary 0 7 for octal 0 9 for decimal and 0 9 a f and A F for hexadecimal 108 Illegal character An illegal character in a label Valid characters for labels are alphabetic a f A F numeric 0 9 the underscore _ and the question mark Labels may not begin with a numeric 109 Unmatched An open parenthesis did not have a matching close parenthesis For example DATA 1 2 110 Unmatched An close parenthesis did not have a matching open parenthesis For example DATA 142 111 Missing symbol An equ or set directive did not have a symbol to which to assign the value 112 Missing operator An arithmetic operator was missing from an expression For example DATA 1 2 113 Symbol not previously defined A symbol was referenced that has not yet been defined Check the spelling and location of the declaration of any symbols used in your code Only addresses may be used as forward references Constants and variables must be declared before they are used This sometimes happens when include files are used in your project Since the text from an include file is inserted at the location of the include statement and you may have labels used before that point you can get this error Also the error may occur due to a typing error spelling mistake or case change in your label MyLabel is not the same as Mylabel unless case sensitivity is turned off it is on by default
232. ils are handled by the include files inc or linker script files 1kr 4 4 4 See Also maxram 4 4 5 Simple Example include p16c622 inc __maxram OxOBF badram 0x07 0x09 OxOD OxE badram 0x87 0x89 0x8D Ox8F Ox9E movwf 0x07 Generates invalid RAM warning movwf 0x87 Generates invalid RAM warning and truncation message 4 5 badrom IDENTIFY UNIMPLEMENTED ROM Note badromis preceded by two underline characters 4 5 1 Syntax badrom expr exprl expr expr 4 5 2 Description The maxromand badron directives together flag accesses to unimplemented registers badrom defines the locations of invalid ROM addresses This directive is designed for use with the maxrom directive maxrom directive must precede any badrom directive Each expr must be less than or equal to the value specified by maxrom Once the maxrom directive is used strict ROM address checking is enabled using the ROM map specified by badrom To specify a range of invalid locations use the syntax minloc maxloc Specifically a warning will be raised in the following circumstances the target of a GOTO or CALL instruction is evaluated by the assembler to a constant and falls in a bad ROM region the target of an LGOTO or LCALL pseudo op is evaluated by the assembler to a constant and falls in a bad ROM region e a hex file is being generated and part of an instruction falls in a bad ROM region 20
233. ined not in the boot loader but in the application source code DS33014J page 206 2005 Microchip Technology Inc Sample Applications kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk kkkkkk kkkkkkkk 18Fboot_r asm kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk LIST P 18F8722 include P18cxxx inc Declare labels used here but defined outside this module extern RVReset RVIntH RVIntL kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Vectors code 0x0000 VReset bra Boot Start IntH code 0x0008 VIntH bra RVIntH Re map Interrupt vector IntL code 0x0018 VIntL bra RVIntL Re map Interrupt vector s kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Boot code 0x002A Define explicit Bootloader location Boot Start Determine if bootloader should execute or branch to user s code bra RVReset Branch to user s application code Else Bootloader execution starts here kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk END main r asm This is a sample version of a main source code file that uses the GLOBAL directive to make the relocatable reset and interrupt vector labels available to the boot loader kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk main r asm kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk LIS
234. ing library files Libraries make linking easier Since library files can contain many object files the name of a library file can be used instead of the names of many separate object files when linking Libraries help keep code small Since a linker only uses the required object files contained in a library not all object files which are contained in the library necessarily wind up in the linker s output module Libraries make projects more maintainable If a library is included in a project the addition or removal of calls to that library will not require a change to the link process Libraries help to convey the purpose of a group of object modules Since libraries can group together several related object modules the purpose of a library file is usually more understandable than the purpose of its individual object modules For example the purpose of a file named math 1ibis more apparent than the purpose of power o ceiling o and floor o 2005 Microchip Technology Inc DS33014J page 227 Assembler Linker Librarian User s Guide 15 4 HOW MPLIB LIBRARIAN HELPS YOU The MPLIB librarian can help you in the following ways The librarian makes linking easier because single libraries can be included instead of many smaller files The librarian helps keep code maintainable by grouping related modules together The librarian commands allow libraries to be created and modules to be added listed replaced deleted or extracte
235. ing romdata into section DATTBL unsigned rom data DATA SIZE Hpragma romdata Set back to default romdata section Configuration Bits Setup The pragma config directive specifies the processor specific configuration settings i e configuration bits to be used by the application For more on this directive see the MPLAB C18 C Compiler User s Guide DS51288 Hpragma config OSCS ON OSC LP Enable OSC switching and LP pragma config PWRT ON Enable POR pragma config BOR ON BORV 42 Enable BOR at 4 2v pragma config WDT OFF Disable WDT pragma config MODE EM Use Extended MCU mode Main application code for default CODE section void main void while 1 end while end main 13 4 2 Assembler Source Code eeprom2 asm eeprom2 asm list p 18f8720 include p18f8720 inc INTHAND code place interrupt handling code in here end DS33014J page 196 2005 Microchip Technology Inc Sample Applications Id File 13 4 3 Linker Script eeprom Ikr 18 8720 1kr v 1 1 2003 12 16 14 53 08 GrosbaJ Exp 18 8720 1kr Sample linker script for the PIC18F8720 processor Modified for MPLINK Linker Sample Application 1 LIBPATH FILES c018i o FILES clib lib FILES p18f8720 1ib CODEPAGE CODEPAGE CODEPAGE CODEPAGE CODEPAGE CODEPAGE CODEPAGE ACCESSBANK NAM Za AM ua AM AM uz A AM z A
236. ing used to identify an area in RAM addris a decimal e g 30 or hexadecimal e g OXFF number specifying an address The optional keyword PROTECTED indicates a region of memory that only can be used when specifically identified in the source code The linker will not use the protected area 2005 Microchip Technology Inc DS33014J page 183 Assembler Linker Librarian User s Guide Special Func DATABANK NAM DATABANK NAM DATABANK NAM DATABANK NAMI General Purp DATABANK NAM DATABANK NAM DATABANK NAM DATABANK NAM SHAREBANK SHAREBANK SHAREBANK SHAREBANK NAM NAMI NAMI NAMI EXAMPLE 11 5 RAM EXAMPLE Based on the RAM memory layout shown in PIC16F877A Register File Map the DATABANK and SHAREBANK entries in the linker script file would appear as shown in the examples below the map PIC16F877A Register File Map Address Bank 0 Bank 1 Bank 2 Bank 3 00h INDFO INDFO INDFO INDFO 01h TMRO OPTION REG TMRO OPTION REG 02h PCL PCL PCL PCL 03h STATUS STATUS STATUS STATUS 04h FSR FSR FSR FSR 05h PORTA TRISA OFh TMR1H EEADRH 10h T1CON x iFh ADCONO ADCON1 General Purpose General Purpose 20h RAM Banked RAM Banked General Purpose General Purpose RAM Banked RAM Banked 6Fh 70h General Purpose RAM Unbanked 7Fh RAM Memory Declarations for PIC16F877A Banked Memory
237. initialized to the specified address or will be assigned at link time if no address is specified No code can be placed by the user in this segment The linker will generate a look up table entry for each byte specified in an idata section You must then link or include the appropriate initialization code Examples of initialization code that may be used and modified as needed may be found with MPLINK linker sample application examples The res db and dw directives may be used to reserve space for variables res will generate an initial value of zero db will initialize successive bytes of RAM dw will initialize successive bytes of RAM one word at a time in low byte high byte order 4 36 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation DS33014J page 86 2005 Microchip Technology Inc Directives Use this directive to initialize your variables or use a udata directive and then initialize your variables with values in code It is recommended that you always initialize your variables Relying on RAM initialization can cause problems especially when using an emulator as behavioral differences between the emulator and the actual part may occur 4 36 4 See Also extern global udata udata acs udata ovr udata shr 4 36 5 Simple Example idata acs LimitL dw 0 LimitH dw D 300 Gain dw D 5 Flags db O String db Hi there
238. ion for any processor For PIC18 devices reserve memory word bytes are packed If an odd number of bytes is specified a O will be added unless in a code pack section See the description for code pack for more infomation For all other PICmicro devices reserve memory words with 8 bit data Each expr must evaluate to an 8 bit value The upper bits of the program word are zeroes Each character in a string is stored in a separate word 4 17 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is designed mainly for initializing data in the EE data memory region of PICmicro devices with EE data Flash For PIC18 devices make sure to specify the start of data memory at OxF00000 For other PICmicro devices make sure to specify the start of data memory at 0x2100 Always check your device programming specification for the correct address 4 17 4 See Also data db dt dw code pack 4 17 5 Simple Example Initialize EEPROM data on a PIC16 device org 0x2100 de My Program v1 0 0 2005 Microchip Technology Inc DS33014J page 67 Assembler Linker Librarian User s Guide 4 18 define 4 17 6 PIC16 Application Example de Hinclude p16f877a inc Include standard header file for the selected device org 0x2100 The absolue address 2100h is mapped to the 0000 location of EE data memory
239. iption Force immediate return from macro expansion during assembly The effect is the same as if an endm directive had been encountered 4 30 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation Use this directive to prematurely end a macro usually for a specific condition This is similar to the C language command break 4 30 4 See Also endm macro 4 30 5 Simple Example test macro filereg if filereg check for valid file exitm else error bad file assignment endif endm 4 30 6 Application Example exitm This program demonstrates the exitm assembler directive which causes an immediate exit from a macro It is used in the example to exit from the macro when certain conditions are met include p16f877a inc Include standard header file for the selected device result equ 0x20 Assign value 20H to label result RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST DS33014J page 78 2005 Microchip Technology Inc Directives pagesel start goto start add MACRO numl num2 if numl gt 0xff exitm else if num2 gt 0xff exitm else movlw numi movwf result movlw num2 addwf result endif endif endm org 0010 start add 100 256 end Jumps to the location labelled
240. ired ifdef AlternateASM MyPort equ PORTC Use Port C if AlternateASM defined MyTris equ TRISC TRISC must be used to set data direction for PORTC else MyPort equ PORTB Use Port B if AlternateASM not defined MyTris equ TRISB TRISB must be used to set data direction for PORTB endif banksel MyTris clrf MyTris Set port to all outputs banksel MyPort Return to bank used for port movlw 55h Move arbitrary value to W reg movwf MyPort Load port selected with 55h end DS33014J page 90 2005 Microchip Technology Inc Directives 4 39 7 Application Example 2 ifdef This program uses the control directive define along with the ifdef else and endi f directives to selectively assemble code for use with either an emulator or an actual part The control directive define is used to create a flag to indicate how to assemble the code for the emulator or for the actual device include p18f452 inc Hdefine EMULATED Comment out with if actual part INIT Hifdef EMULATED If emulator used add lines of movlw 0xb0 initialization code to work around movwf Oxf9c table read limitation Hendif 4 40 ifndef EXECUTE IF SYMBOL HAS NOT BEEN DEFINED 4 40 1 Syntax Preferred ifndef label Supported Hifndef label 4 40 2 Description If 1abe1 has not been previously defined or has been undefined by issuing an undefine directive then the code following the directive will be assembled
241. is always 0x0 according to the programming specification include p18f452 inc Include standard header file for the selected device idlocs _IDLOCO 0x1 IDLOC register 0 will be programmed to 1 idlocs _IDLOC1 0x2 IDLOC register 1 will be programmed to 2 idlocs IDLOC2 0x3 IDLOC register 2 will be programmed to 3 idlocs IDLOC3 0x4 IDLOC register 3 will be programmed to 4 idlocs _IDLOC4 0x5 IDLOC register 4 will be programmed to 5 idlocs _IDLOC5 0x6 IDLOC register 5 will be programmed to 6 idlocs IDLOC6 0x7 IDLOC register 6 will be programmed to 7 idlocs IDLOC7 0x8 IDLOC register 7 will be programmed to 8 4 38 if BEGIN CONDITIONALLY ASSEMBLED CODE BLOCK 4 38 1 Syntax Preferred if expr Supported dif expr if expr 4 38 2 Description Begin execution of a conditional assembly block If expr evaluates to true the code immediately following the i will assemble Otherwise subsequent code is skipped until an e1se directive or an endif directive is encountered An expression that evaluates to zero is considered logically FALSE An expression that evaluates to any other value is considered logically TRUE The if and while directives operate on the logical value of an expression A relational TRUE expression is guaranteed to return a nonzero value FALSE a value of zero if s may be nested up to 16 deep 4 38 3 Usage This directive i
242. is is the principal difference between symbols declared as constant and those declared as variable or created by the set directive Otherwise constants and variables may be used interchangeably in absolute code expressions 4 13 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation Although equ or cblock is more generally used to create constants the constant directive also works 4 13 4 See Also set variable equ cblock 4 13 5 Examples See the examples under variable 4 14 da STORE STRINGS IN PROGRAM MEMORY PIC12 16 MCUs 4 14 1 Syntax label da expr expr2 exprn 4 14 2 Description da Data ASCII Generates a packed 14 bit number representing two 7 bit ASCII characters 4 143 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is useful for storing strings in memory for PIC16 MCU devices 4 14 4 Simple Examples da abcdef will put 30E2 31E4 32E6 into program memory da 12345678 0 will put 1882 19B4 1AB6 1BB8 0000 into program memory da OxFFFF will put 0x3FFF into program memory 4 14 5 Application Example da This example shows the usefulness of directive da in storing a character string in the program memory of 14 bit architecture devices This directive gener
243. is unassigned then it gets allocated after the relocatable assigned sections and before the other relocatable unassigned sections are allocated DS33014J page 188 2005 Microchip Technology Inc Linker Processing 12 4 RELOCATION EXAMPLE The following example illustrates how the linker relocates sections Suppose the following source code fragment occurred in a file File ref c char varl Line 1 void setVarl void Line 2 varl OxFF Line 3 Suppose this compiles into the following assembly instructions Note This example deliberately ignores any code generated by MPLAB C18 to handle the function s entry and exit 0x0000 MOVLW OxFF 0x0001 MOVLR Need to patch with varl s bank 0x0002 MOVWF Need to patch with varl s offset When the compiler processes source line 1 it creates a symbol table entry for the identifier var1 which has the following information Symbol index gt name varl value 0 section data class extern When the compiler processes source line 3 it generates two relocation entries in the code section for the identifier symbol var1 since its final address is unknown until link time The relocation entries have the following information Reloc index gt address 0x0001 symbol varl type bank Reloc index gt address 0x0002 symbol varl type offset Once the linker has placed every section into target memory the final addresses are known Once all ident
244. l should be specified No operations can be performed on 1abe1 This label must have been previously defined The linker will generate the appropriate bank selecting code For 12 bit instruction width PIC10F some PIC12 PIC16 devices the appropriate bit set clear instructions on the FSR will be generated For 14 bit instruction width most PIC12 PIC16 devices bit set clear instructions on the STATUS register will be generated For PIC18 devices a movlb will be generated If the device contains only one bank of RAM no instructions will be generated 4 7 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive may be used with all PlCmicro devices This directive is not needed for variables in access RAM PIC18 devices 4 7 4 See Also bankisel pagesel 4 7 5 Simple Example banksel Varli Select the correct bank for Vari movwf Varl Write to Varl DS33014J page 52 O 2005 Microchip Technology Inc Directives 4 7 6 Application Example banksel This program demonstrates the bankse1 directive This directive generates the appropriate code to set clear the RPO and RP1 bits of the STATUS register include p16f877a inc Include standard header file for the selected device groupl udata 0x20 groupl data stored at locations starting at 0x20 bank 0 groupl varl res 1 groupl varl located at 0x2
245. l 5 a 103 pageselw u tee REG RE eR et AR DE 105 udataz subo eed 111 Udala ACS oues EE RL 112 Udala OVI ert e ip 114 ddala Shr ssi euet 116 Object Files Precompiled 12 Object Module Generating 150 Operators Arithmatic 42 OR logical nene eee eden 43 epe 100 P Dag x xit ord det ee Cie aie Dc e tae Soo 103 Page EJect oi s eth he ees 103 Page Selection 103 Page Selection WREG 105 pagesel eat wee atari einen 103 149 AA Mn semaines 105 Paglrig cinta ene 129 149 PAT Asian e pee eut e 192 Processing Linker 187 processor sete e RU 106 Processor Set 93 106 125 Program Memory sse 144 Projects eire t ee eto 11 PROTECTED xiu bee 183 2005 Microchip Technology Inc DS33014J page 268 R RAGIN dats oe ano MR RR PRA ERIS 41 coq E CE 106 Radix Seb aea k area Eiss 93 106 107 125 RAM Allocation oooooocccccncccccccnccononcccnnnonanaccncncnnnnncnos 147 RAM Memory Regions Defining 183 Reading Recommended 5 Register Assignments 129 relocatable iuris ote tab pia hae ents 30 Relocatable Code Generating 23 Relocatable Objects 143 CO et 107 Reserved Section N
246. l distance3 Define symbol distance3 as 10 distance2 15 Give distance2 an initial value distance2 distancel distance2 Add distancel to distance2 Variable assignments increments and decrements must be placed on separate lines distance3 set 15 Change value of distance3 distance2 distance2 distance3 Add distance3 to distance2 movlw distance2 Move value of distance2 movwf distance reg into distance reg goto Start Loop back to Start end 5 4 3 Using Watch Windows Once the program begins the value of Tdistance1 is placed into distance reg This can be observed in a watch window in MPLAB IDE where the value of distance reg Will become 50 The symbol Tdistance1 will not be found in the watch window symbol list as symbols defined using the define directive are not available for viewing in MPLAB IDE because they are not RAM variables The final lines of the example program write the final value of distance2 to distance reg If you had a watch window open to see distance reg loaded with the value of 50 you will see it change to 3A Remember that the radix is hexadecimal so hex addition was used to determine the distance2 value Sa cA C C C 4 A A a rcc H M amp 2005 Microchip Technology Inc DS33014J page 133 Assembler Linker Librarian User s Guide 5 5 EXAMPLE OF A 32 BIT DELAY ROUTINE Directives highlighted in this example are macro endm banksel 5 5 1 Program Functional
247. label data text string text string 4 15 2 Description Initialize one or more words of program memory with data The data may be in the form of constants relocatable or external labels or expressions of any of the above The data may also consist of ASCII character strings text string enclosed in single quotes for one character or double quotes for strings Single character items are placed into the low byte of the word while strings are packed two to a word If an odd number of characters are given in a string the final byte is zero On all families except the PIC18 device family the first character is in the Most Significant Byte of the word On the PIC18 device family the first character is in the Least Significant Byte of the word A PP J ee DS33014J page 62 2005 Microchip Technology Inc Directives 4 15 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation When generating a linkable object file this directive can also be used to declare initialized data values Refer to the idata directive for more information db and other data directives are more commonly used than data 4 15 4 See Also db de dt dw idata 4 15 5 Simple
248. label must be specified on the line 4 34 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation When your project uses more than one file you will be generating linkable object code When this happens you may use the global and extern directives global is used to make a label visible to other files extern must be used in the file that uses the label to make it visible in that file 4 34 4 See Also extern idata udata udata acs udata ovr udata shr 4 34 5 Simple Example global Varl Var2 global AddThree udata Varl res 1 Var2 res 1 code AddThree addlw 3 return DS33014J page 84 O 2005 Microchip Technology Inc Directives 4 34 6 Application Example extern global See this example under extern 4 35 idata BEGIN AN OBJECT FILE INITIALIZED DATA SECTION 4 35 1 Syntax label idata RAM address 4 35 2 Description This directive declares the beginning of a section of initialized data If 1abe1 is not specified the section is named idata The starting address is initialized to the specified address or will be assigned at link time if no address is specified No code can be placed by the user in this segment The linker will generate a look up table entry for each byte specified in an idata section You must then link or include the appropriate initialization code Examples of initialization code that may be u
249. lates for your own application How to Build the Sample Applications Sample Application 1 Modifying the Linker Script How to find and use template files How to modify the linker script file Sample Application 2 Placing Code and Setting CONFIG Bits How to place program code in different memory regions How to place data tables in ROM memory How to set configuration bits in C Sample Application 3 Using a Boot Loader How to partition memory for a boot loader How to compile code that will be loaded into external RAM and executed Sample Application 4 Configuring External Memory How to create a new linker script memory section How to declare external memory through pragma code directive How to access external memories using C pointers 13 2 HOW TO BUILD THE SAMPLE APPLICATIONS To build the sample applications you will need the MPASM assembler the MPLINK linker and for some sample applications the MPLAB C18 C compiler installed on your PC The assembler and linker are automatically installed with MPLAB IDE or may be acquired separately on the Microchip website or the MPLAB C18 CD ROM A free demo student version of the MPLAB C18 C compiler may be obtained on the Microchip website The full MPLAB C18 C compiler must be purchased separately 13 21 Using MPLAB IDE To build an application with MPLAB IDE 1 Use the Project Wizard under the Project menu to create a project Select the device specif
250. le must begin with a directive keyword or the comment Delimiter LL A a A AA s n AAA DS33014J page 214 2005 Microchip Technology Inc Errors Warnings and Common Problems 14 3 LINKER ERRORS MPLINK linker errors are listed alphabetically below Absolute code section secName must start at a word aligned address Program code sections will only be allocated at word aligned addresses MPLINK will give this error message if an absolute code section address is specified that is not word aligned Configuration settings have been specified for address 0x300001 in more than one object module Found in foo o previously found in bar o This error is issued when MPLAB C18 s pragma config directive has been used in two separate c files e g foo c and bar c with settings specified from the same configuration byte Set configuration bits for a given byte in a single c file Conflicting types for symbol symName Symbol symName is defined in different locations as different types Could not find definition of symbol symName in file filename A symbol symName is used without being defined in file filename Could not find file filename An input object or library file was specified which does not exist or cannot be found in the linker path Could not open map file filename for writing Verify that if filename exists it is not a read only file Could not re
251. list of configuration bit setting definitions This list sets the PIC18 processor s configuration bits represented by setting to a value described by value Refer to individual PIC18 microcontroller data sheets for a description of the configuration bits Available settings and values maybe found in both the standard processor include inc files and the PIC18 Configuration Settings Addendum DS51537 Multiple settings may be defined on a single line separated by commas Settings for a single configuration byte may also be defined on separate lines Before this directive is used a PIC18 MCU must be declared through the command line the 1ist directive the processor directive or Configure Select Device in MPLAB IDE 2005 Microchip Technology Inc DS33014J page 59 Assembler Linker Librarian User s Guide Another directive that may be used to set configuration bits for PIC18 MCU devices is the config directive but this is not recommended for new code Note Donotmix config and config directives in the same code 4 12 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is placed in source code so that when the code is compiled assembled into a hex file the configuration values are preset to desired values in your application This is useful when giving your files to a third party p
252. ll be created The error map file contains only section information no symbol information is provided The error map file lists all sections that were successfully allocated when the error occurred This file in conjunction with the error message should provide enough context to determine why a section could not be allocated 2005 Microchip Technology Inc DS33014J page 177 Assembler Linker Librarian User s Guide NOTES DS33014J page 178 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 10 Linker Interfaces INTRODUCTION MPLINK object linker usage is discussed When MPLAB IDE or MPLAB C18 is installed the MPLINK linker mplink exe is also installed Topics covered in this chapter MPLAB IDE Interface Command Line Interface Command Line Example 10 2 MPLAB IDE INTERFACE The MPLINK linker is commonly used with the MPASM assembler in an MPLAB IDE project to generate relocatable code For more information on this use see PlCmicro Language Tools and MPLAB IDE The linker may also be used in MPLAB IDE with the MPLAB C18 C compiler For more information on Microchip compilers see the MPLAB C18 C compiler documentation listed in Recommended Reading 10 3 COMMAND LINE INTERFACE MPLINK linker can be used in MPLAB IDE or directly from a command line When used in MPLAB IDE all of MPLINK linker s options are available through the MPLINK Linker tab access
253. low byte of address movlw low CTR_Table high Return high byte of address movlw high CTR Table upper Return upper byte of address movlw upper CTR Table Multiply a b zc Divide a b c Modulus entry_len tot_len 16 Add tot len entry len 8 1 Subtract entry len tot 1 8 Left shift flags flags 1 gt gt Right shift flags flags gt gt 1 gt Greater or equal if entry idx gt num entries gt Greater than if entry idx gt num entries lt Less than if entry idx lt num entries lt Less or equal if entry idx lt num entries Equal to if entry idx num entries Not equal to if entry idx num entries amp Bitwise AND flags flags amp ERROR BIT i Bitwise exclusive OR flags flags ERROR BIT Bitwise inclusive OR flags flags ERROR_BIT amp amp Logical AND if len 512 amp amp b c Logical OR if len 512 b c Set equal to entry_index 0 Add to set equal entry index Subtract set equal entry index 1 Multiply set equal entry index entry length Divide set equal entry total entry length Modulus set equal entry index 8 lt lt Left shift set equal flags lt lt 3 gt gt Right shift set equal flags gt gt 3 amp AND set equal flags amp ERROR FLAG Inclusive OR set equal flags ERROR FLAG Exclusive OR set equal flags ERROR_FLAG Increment 2 i Decrement Es Note 1 This p
254. lues for constants in your program Note A processor specific include file exists with predefined SFR names It is recommended that you use this file instead of defining the variables yourself See include for how to include a file in your program This directive is also useful with the ifdef and ifndef directives which look for the presence of an item in the symbol table 4 18 4 See Also undefine include ifdef ifndef 4 18 5 Simple Example define length 20 define control 0x19 7 define position X Y Z Y 2 Z X test label dw position 1 length 512 bsf control set bit 7 in 19 4 18 6 Application Example define undefine This example shows the usage of define and undefine directives A symbol name previously defined with the define directive is removed from the symbol table if tundef ine directive is used The same symbol may be redefined again include p16f877a inc Include standard header file for the selected device area set 0 The label area is assigned the value 0 define lngth 50H Label lngth is assigned the value 50H Hdefine wdth 25H Label wdth is assigned the value 25H area set lngth wdth Reassignment of label area So area will be reassigned a value equal to 50H 25H undefine Ilngth Undefine label lngth undefine wdth Undefine label wdth define lngth 0 Define label lngth to 0 end By using the above directives 1ngth will be
255. me source file are not permitted to have the same name 4 64 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation This directive is similar to udata except that it is only used on parts with memory accessible from multiple banks udata shr sections are used with SHAREBANK locations in the linker script where as udata sections are used with DATABANK locations in the linker script See the data sheet for the PIC16F873A for a specific example 4 64 4 See Also extern global idata udata udata acs udata ovr 4 64 5 Simple Example Temps udata_shr Tempi res 1 Temp2 res 1 Temp3 res 1 4 64 6 Application Example udata shr This program demonstrates the udata shr directive This directive declares the beginning of a section of shared uninitialized data This directive is used to declare variables that are allocated in RAM that is shared across all RAM banks i e unbanked RAM include p16f877a inc Include standard header file for the selected device shared data udata shr Declares the beginning of a data section named shared data var res 1 which is shared by all banks var is the location which can be accessed irrespective of banksel bits bankO var udata 0X20 Declares beginning of a data varo res 1 section named bank0_var which is in bank0 var0 is allocated the address 0x20 DS33014J page 116
256. mmand Shell Interface ee 33 AbSsOollte ont eta tere o eate 188 Common Problems Relocatable eseeseeeeeneeneneen 188 E ne m ar ue 223 Stack i o io T 188 Conditional Assembly Directives 46 AND logical ees teetenteeseeseessensenneenensenees 43 GlSOr as e EE eed fae EE e dl a e A 71 Arithmatic Operators eseseeeenenene 42 Bde c cce he D d oe 72 ASCII Character Set 249 O Te es Net 73 AUTOEXEC BAT ES 37 f EE 72 B Tun 88 badra cusco a Line dde 48 hg EE 90 badroM idas 49 nee NIE Orat Ofte ay ML tig RUD eee SA Bank Selecting di ninia e eite 52 E a I X zc d 0 1 p A Configuration Bis 56 59 148 NN NOR 50 eli aii 60 EXT PS NN OM UR 52 149 c eee NURSES RNC DE 156 Bit Assignments eeen 129 Blank Listing Lines 110 Block Of E M ns SAT A 54 72 Declare A evel A ath der 60 Dot adds s e dor nr seriestesec ns 74 O 2005 Microchip Technology Inc DS33014J page 265 Control Directives 46 Documentation POSTING Gat iso cathe nine tt hannis idee 68 Conventions 4 e A nt as 92 Layoul ue teu iube Be 1 amp undefine oooconccnncccnccccconononnccnnnnonononononanarononnns 117 PM EET 70 Constant ssh entame re Lu ue 60 QW sic nat eere RE 39 70 lo 71 E ciet M 74 OR 100 EEPROM Data Byte see 67 POCOS nce certet sent 106 Eight by Eight Multiply ne 155 adix ins 106 C5 LY aR EA A EAA E E 71 COL mel A OEE TS 1
257. mory location addressed by result and load the result back to result endm end of add MACRO ORG 0x0010 Main program starts at 10H start The label start is assigned an address 10H add 100 90 Call add MACRO with decimal numbers 100 and 90 assigned to numl1 and num2 labels respactively 100 and 90 will be added and the result will be in result end 4 45 maxram DEFINE MAXIMUM RAM LOCATION Note maxram is preceded by two underline characters 4 45 1 Syntax __maxram expr 4 45 2 Description The maxramand badran directives together flag accesses to unimplemented registers maxram defines the absolute maximum valid RAM address and initializes the map of valid RAM addresses to all addresses valid at and below expr expr must be greater than or equal to the maximum page 0 RAM address and less than 1000H This directive is designed for use with the badram directive Once the maxram directive is used strict RAM address checking is enabled using the RAM map specified by badram maxram can be used more than once in a source file Each use redefines the maximum valid RAM address and resets the RAM map to all locations 4 45 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation 2005 Microchip Technology Inc DS33014J page 97 Assembler Linker Librarian User s
258. n configured for Extended Microcontroller mode external program memory space from locations 20000h through 1FFFFFh becomes externally addressable through the EMB created from the I O pins The use of a linker script file can be extended to other external memory mapped devices such as programmable l O peripherals real time clocks or any device that has multiple configuration or control registers that can be accessed through an 8 or 16 bit data bus 13 6 1 MPLAB C18 Usage The MPLAB C168 linker script file for the PIC18F8722 is modified to instruct the linker that a new memory region is available by adding a CODEPAGE definition as shown below The use of the PROTECTED modifier prevents the linker from assigning any relocatable code to this region The name xsram is arbitrary and can be any desired name What is important are the START and END addresses which should match the physical memory address range of the external memory being used CODEPAGE NAME xsram START 0x020000 END 0x01FFFFF PROTECTED In addition to the new CODEPAGE a new logical SECTION is created and assigned to the program memory region specified in the associated CODEPAGE definition SECTION NAME SRAM BASE ROM xsram In the MPLAB C18 application s source code file the pragma romdata directive instructs the linker to allocate the SRAM s starting address to the memory region specified by the SRAM BASE logical section definition The physical address is provided
259. nclude INCLUDE ADDITIONAL SOURCE FILE 4 41 1 Syntax Preferred include include file include include file include include file Supported include include file include include file include include file gt 4 4 2 Description The specified file is read in as source code The effect is the same as if the entire text of the included file were inserted into the file at the location of the include statement Upon end of file source code assembly will resume from the original source file Up to 5 levels of nesting are permitted Up to 255 include files are allowed If include file contains any spaces it must be enclosed in quotes or angle brackets If a fully qualified path is specified only that path will be searched Otherwise the search order is current working directory source file directory MPASM assembler executable directory 4 4 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation You should use the include directive once to include that standard header file for your selected processor This file contains defined register bit and other names for a specific processor so there is no need for you to define all of these in your code DS33014J page 92 2005 Microchip Technology Inc Directives 4 41 4 See Also Hdefine undefine 4 41 5 Simple Example include p18f452 inc s
260. nerated by MPLINK linker can be viewed by selecting File gt Open in MPLAB IDE and choosing the file you specified in the MPLINK linker options It provides information on the absolute location of source code symbols in the final output It also provides information on memory use indicating used unused memory This window is automatically reloaded after each rebuild The map file contains four tables The first table Section Info displays information about each section The information includes the name of the section its type beginning address whether the section resides in program or data memory and its size in bytes There are four types of sections code initialized data idata uninitialized data udata initialized ROM data romdata The following table is an example of the section table in a map file Section Info Section Type Address Location Size Bytes Reset code 0x000000 program 0x000002 cinit romdata 0x000021 program 0x000004 code code 0x000023 program 0x000026 udata udata 0x000020 data 0x000005 The second table Program Memory Usage lists program memory addresses that were used and provides a total usage statistic For example Program Memory Usage Start End 0x000000 0x000005 0x00002a 0x00002b 0x0000bc 0x001174 0x001176 0x002895 10209 out of 32786 program addresses used program memory utilization is 31 The third table in the map file Symbols Sorted by Name provides information about
261. nes p 110 e subtitle Specify Program Subtitle p 110 e title Specify Program Title p 111 4 2 5 Macro Directives Macro directives control the execution and data allocation within macro body definitions endm End a Macro Definition p 73 exitm Exit from a Macro p 78 expand Expand Macro Listing se p 80 e local Declare Local Macro Variable p 94 macro Declare Macro Definition p 96 e noexpand Turn off Macro Expansion p 100 4 2 6 Object File Directives Object file directives are used only when creating an object file e access ovr Begin an Object File Overlay Section in Access RAM PICI8 MEUS etre ia e eret aere A nate p 56 bankisel Generate Indirect Bank Selecting Code PIC12 16 MCUS p 50 e banksel Generate Bank Selecting Code p 52 e code Begin an Object File Code Section p 56 code pack Begin an Object File Packed Code e Section PIC18 MCUS iii p 65 e extern Declare an Externally Defined Label ssss p 80 global Export a Label p nun epar eese p 84 e idata Begin an Object File Initialized Data Section p 85 idata acs Begin an Object File Initialized Data Section e in Access RAM PIC18 MCUS nennen nennen p 94 e pagesel Generate Page Selecting Code PIC10 12 16 MCUs p 103 pageselw Generate Page Selecting Code Using
262. nnnnocccccconncccnnonnncnnnnnannccnnnnnnn conca nn nnnnnnnnes 139 5 9 TIPS And Treks i ea nd set an mate 139 Chapter 6 Relocatable Objects 61 LA 140 10 UICN suae ctos enean ls a Mean ct UE 143 6 2 Header Files Re 143 6 3 Program M mMOn see idee et ere nee era NEATE KSE 144 6 4 Low High and Upper Operands ccccoonoccccconocccccononccnnncnnncnononannccnnnnnnncnnnnnnnos 144 9 5 RAMA lO CARON nes ate todas Ron SE Se nent den 147 6 6 Configuration Bits and ID Locations 0ooocccconncccc nonaccccnonancnonanncnnnnnarccnnnnnnno 148 6 7 Accessing Labels From Other Modules sese 148 6 8 Paging and Banking Issues ss reete ete tue re Ende n 149 6 9 Generating the Object Module occconocccnnnocccccnnancccnonanancnonnoncnnnnnnnrnnnnnannnos 150 6 10 Gode Example diei elita eb cope tte tutem 150 2005 Microchip Technology Inc DS33014J page v Assembler Linker Librarian User s Guide Chapter 7 Macro Language o M INTOAUCTION mE TTL UTEM 153 72 Macro SMA V dd 159 7 3 Macro Directives Defined cccoonncccccoonnonnconoconccnonconononnnonononononrnnnononnnnnnnnnos 154 7 4 Macro Definition iii 154 7 5 Macro INVOCA di 154 7 6 Macro Gode Examplas sace cud atenta Re Tn pur bala eau e is 155 Chapter 8 Errors Warnings Messages and Limitations 8 4 Introducti r titer te ect Eric tes Fai Lada hn E 157 8 2 Assembler ErTOIS dee nce ete ctt e eet eon ete E td 157 8 3 Assembler Warnings ss 163 8 4 Assembler Message
263. nput Output Files sains Y nre He DEF A ERR Ix He ei e ER EEG 229 Chapter 16 Librarian Interfaces 161 o i gere 0161110 RR COT TTD DITE 231 16 2 MPEABJIDE Interface cui ea 231 16 3 Command Line Options cst annales 232 16 4 Command Line Examples and Tips ooooocccccccnonicoonnnncccnonanononcnnnnnnnnnannnnnnnos 232 Chapter 17 Errors LAA ANTOPUCTION EET 233 17 2 Librarian Parse Errors oooocccccocncnnncococononnoncononnononnonnononnrnnnnnnrononnnnnonenoninonos 233 17 3 Library File Errors e rete Reit eec ues eR Certe aban 233 TE A GOFF File Errors e oo ete ee eie entere ot fee 233 2005 Microchip Technology Inc DS33014J page vii Assembler Linker Librarian User s Guide Part 4 Appendices Appendix A Instruction Sets AGA IntrodUctlOI oorr roe ie i E ree va eoe or Tela 237 A 2 Key to 12 14 Bit Instruction Width Instruction Sets ssss 237 A 3 12 Bit Instruction Width Instruction Set sseseem 239 A 4 14 Bit Instruction Width Instruction Set sseem 240 A 5 12 Bit 14 Bit Instruction Width Pseudo Instructions 242 A 6 Key to PIC18 Device Instruction Set nes 243 A 7 PIC18 Device Instruction Set ses 244 A 8 PIC18 Device Extended Instruction Set seseee 248 Appendix B Useful Tables B1 Tritroductlon isset cease pe EE A PU P VA DC EET Ee agp rese a dias 249 B 2 ASGIE C
264. nput files A section with the name secName occurs in more than one input file However in some files itis marked as either an absolute access overlay or shared section and in some it is not Change the section s type in the source files and rebuild the object modules Section secName can not fit the absolute section Section secName start 0xHHHH length 0xHHHH A section which has not been assigned to a memory in the linker command file can not be allocated Use the m lt mapfile gt switch to generate an error map file The error map will show the sections which were allocated prior to the error More memory must be made available by adding a CODEPAGE SHAREBANK or DATABANK directive or by removing the PROTECTED attribute or the number of input sections must be reduced Section romName can not have a RAM memory attribute specified in the linker command file Use only the ROM attribute when defining the section in the linker command file Section secName can not fit the section Section secName length 0xHHHH A section which has not been assigned to a memory in the linker command file can not be allocated Use the m lt mapfile gt switch to generate an error map file The error map will show the sections which were allocated prior to the error More memory must be made available by adding a CODEPAGE SHAREBANK or DATABANK directive or by removing the PROTECTED attribute or the number of input sections must be red
265. ns 65 CDIOCle 2 te perite teet ees 55 denon nata id e ela te led Ma 67 COM gt ER a a T EREE 56 125 OR A ce A a O 70 constantius oia 119 132 nn AE E AE 70 0 Fa EX 61 OO darse soc 72 dia it 63 64 ile 82 65 66 OS c A de Eur 107 da ET DU e ee 68 Data Section else oot atti diede 89 Access Uninitialized esses 112 o RT 124 A Rb ER 85 Tao ed od EEE ELE 55 Initialized Access 86 endif AA EEE EA 89 Overlayed Uninitialized 114 AMM ais 96 134 Shared Uninitialized 116 o MR 120 Uninitialized eee 111 Cp 109 125 Data Initialized 190 EOP E 75 DATABANK rire etie dido 183 185 role lisa ia 76 pc 65 CXITM rer nee e error de ave EX eee e vv 78 A svedudiadeevewsWevas E 67 GXIOITI iicet means at recae de aan a 81 Decrement xia nacen ea diet 43 fI sies eoi rr dese Pav nidad 83 ein 68 global 52i onde pee Ren 81 136 138 Delete a Substitution Label 117 O a iie An sees anie Ld 85 Directives Assembler 45 CMM IEEE EROS 89 Directives Linker ado ene 182 j e MER Em 90 91 NS tesco hes intero este Der ole DA ot 107 136 A EP 95 MACO FERRER RER een 96 134 2005 Microchip Technology Inc DS33014J page 266 diio
266. nversion Constant Compare 7 6 1 MACRO CODE GENERATION 0 Literal to RAM Conversion This code converts any literal of 32 bits to 4 separate RAM data values In this example the literal 0x12345678 is put in the desired 8 bit registers as 0x12 0x34 0x56 and 0x78 Any literal can be unpacked this way using this macro include p16F877A inc udata 0x20 OutO res al LSB Outl res il d Out2 res 1 H Out3 res 1 MSB Unpack32 MACRO Var Address BANKSEL Address movlw Address movwf FSR movlw Var amp H FF movwf INDF movlw Var gt gt D 08 H FF incf FSR F movwf INDF movlw Var gt gt D 16 amp H FF incf FSR F movwf INDF movlw Var gt gt D 24 H FF incf FSR F movwf INDF ENDM ORG 0 Start Unpack32 0x12345678 0ut0 goto END Var 32 bit literal to be unpacked Address specifies the LSB start Use FSR and INDF for indirect access to desired address Mask to get LSB Put in first location Mask to get next byte of literal Point to next byte Write data to next byte Mask to get next byte of literal Point to next byte Write data to next byte Mask to get last byte of literal Point to last byte Write data to last byte End of the Macro Definition TEST CODE for Unpack32 MACRO Put Unpack Macro here Do nothing loop forever 2005 Microchip Technology Inc DS33014J page 155 Assembler Linker Librarian User s Guide 7 6
267. nversion is complete the object module is generated automatically in MPLAB IDE or by requesting an object file on the command line or in the shell interface When using MPASM assembler for Windows check the checkbox labeled Object File When using the DOS command line interface specify the o option and toggle Assemble to Object File to Yes The output file will have a o extension 6 10 CODE EXAMPLE Since an eight by eight bit multiply is a useful generic routine it would be handy to break this off into a separate object file that can be linked in when required The absolute code file can be broken into two relocatable code files a calling file representing an application and a generic routine that could be incorporated in a library This code was adapted from application note AN617 Please see the Microchip website for a downloadable PDF of this application note EXAMPLE 6 9 ABSOLUTE CODE Input fixed point arguments in AARGBO and BARGBO Output product AARGxBARG in AARGBO AARGB1 Other comments truncated See AN617 PRR RRR ARRE kc he ko eec ke ke he ke he ke e he ke ke ke he ke e he ke ke ce ke ke he ke e he ke kkk k kkk kkk k kkk e he ke ke ke e k k k include p16f877a inc Use any PIC16 device you like LOOPCOUNT EQU 0x20 7 loops needed to complete routine AARGBO EQU 0x21 MSB of result out AARGB1 EQU 0x22 operand A in 8 bits BARGBO EQU 0x23 LSB of result out operand B in 8 bits TestCode clrf AA
268. o OxFF PORTB Delayl PORTB Delay2 Delay2 Loop Loop Set PortB Wait Clear PortB Select Delay2 Page Wait Select Loop Page Repeat Set all PORTB pins high and wait Delay 1 Then set all PORTB pins low and wait Delay 2 Repeat until program halted This will have the effect of flashing the pins of PORTB PRR RR RRR ck ke kc ke ke e he ke ke ke ce ke kkk ke e ke ke ke e he ke e ke ke kkk k Delay 1 Routine Timer0 delay loop PRR RR RE kkk kkk kkk e kkk kkk kk ke e he kk ke k kk k ke e ke ke e kk k Delayl movlw OxFO Set Timer0 value movwf TMRO Ox00 longest delay OXFF shortest delay clrf DFLAG bsf DFLAG DFLO Set flag bit banksel OPTION_REG Select Option Reg Bank 1 bcf OPTION REG TOCS Start Timer0 banksel DFLAG Select DFLAG Bank 0 TLoop Wait for overflow OxFF gt 0x00 btfsc DFLAG DFLO After interrupt DFLO O goto TLoop return Use Timer 0 to create Delay 1 First give the timer an initial value Then enable the timer and wait for it to overflow from OxFF to 0x00 This will generate an interrupt which will end the delay See Section 5 3 7 Interrupts for more information 2005 Microchip Technology Inc DS33014J page 127 Assembler Linker Librarian User s Guide p RRR RRR KER kk KEK KEK KEK KEK KEK KEK KKK KE KE KE KKK KK ck ke ke KKK Delay 2 Routine Decrement delay loop PRR RRR RRR kkk kk kkk kkk kkk k KEK RR ke kkk k ke e ke ke k k k k dec
269. o Operation No Operation Fxxx NOP No Operation No Operation 2 word instructions 0006 POP Pop top of return stack TOS TOS 1 gt TOS 0005 PUSH Push top of return stack TOS PC 2 TOS D 1 n RCALL n Relative Call PC 2 TOS PC 2 2 n gt PC OOFF RESET Software device reset Same as MCLR reset 0010 RETFIE S Return from interrupt TOS gt PC 1 gt GIE GIEH or PEIE GIEL and enable interrupts ifs 1 WREGs gt WREG STATUSs gt STATUS BSRs BSR PCLATU PCLATH unchngd 0012 RETURN S Return from subroutine TOS gt PC if s 1 WREGs gt WREG STATUSs gt STATUS BSRs gt BSR PCLATU PCLATH are unchanged 0003 SLEEP Enter SLEEP Mode 0 gt WDT 0 gt WDT postscaler 1 TO 0 PD DS33014J page 246 2005 Microchip Technology Inc Instruction Sets TABLE A 11 PIC18 LITERAL OPERATIONS Hex Mnemonic Description Function OFkk ADDLW kk Add literal to WREG WREG kk gt WREG OBkk ANDLW kk AND literal with WREG WREG AND kk gt WREG O9kk IORLW kk Inclusive OR literal with WREG WREG OR kk gt WREG EErk LFSR r kk Move literal 12 bit 2nd word kk FSRr FOkk to FSRr 1st word 010k MOVLB k Move literal to BSR lt 3 0 gt kk gt BSR OEkk MOVLW kk Move literal to WREG kk gt WREG ODkk MULLW kk Multiply literal with WREG WREG kk gt PRODH PRODL OCkk RETLW kk Return with literal in WREG kk gt WREG 08kk SU
270. ode Enable PIC18F extended instruction support Default Radix Macro Definitions Restore Defaults Set the default radix either Hexadecimal Decimal or Octal Add macro directive definitions Restore tab default settings Use Alternate Settings Text Box Output Category Enter options in a command line non GUI format Generate Command Line Diagnostics level Select to display errors only errors and warnings or errors warnings and messages These will be shown in the Output window Generate cross reference file Create an cross reference file A cross reference file contains a listing of all symbols used in the assembly code Hex file format for single file assemblies When assembling a single file the assembler may be used to generate a hex file Choose the format here When assembling multiple files the assembler generates object files which must be linked with the linker to generate a hex file Choose the hex file format for the linker in this case Restore Defaults Restore tab default settings Use Alternate Settings Text Box 2005 Microchip Technology Inc Enter options in a command line non GUI format DS33014J page 13 Assembler Linker Librarian User s Guide Build Options Dialog MPLINK Linker Tab Select a category and then set up linker options For additional options see Chapter 10 Linker Interfaces All Options Category Generate
271. on named same var starting at location 0x20 Declares an overlayed uninitialized data section with the same name as the one declared above Thus variables varl and var2 are allocated at the same address The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST Jumps to the location labelled start This is the begining of the code section named PGM It is a relocatable code section Since no absolute address is given along with directive CODE Any operation on varl affects var2 also since both variables are overlaid Go to current line loop here 2005 Microchip Technology Inc DS33014J page 115 Assembler Linker Librarian User s Guide 4 64 udata shr BEGIN AN OBJECT FILE SHARED UNINITIALIZED DATA SECTION PIC12 16 MCUs 4 64 1 Syntax 1abel udata shr RAM address 4 64 2 Description This directive declares the beginning of a section of shared uninitialized data If 1abe1 is not specified the section is named udata shr The starting address is initialized to the specified address or will be assigned at link time if no address is specified This directive is used to declare variables that are allocated in RAM that is shared across all RAM banks i e unbanked RAM No code can be generated in this segment The res directive should be used to reserve space for data Note Two sections in the sa
272. ons are placed in code section RST pagesel start Jumps to the location labelled goto start i start PGMO CODE 0x500 The code section named PGM1 is placed at 0x500 start pagesel pagel pgm address bits 12 amp 11 of pagel pgm are copied to PCLATH 4 amp 3 respectively goto pagel pgm PGM1 CODE 0x900 The code section named PGM1 is placed at 0x900 Label pagel pgm is located in this pagel pom code section goto Go to current line loop here end DS33014J page 104 2005 Microchip Technology Inc Directives 4 53 pageselw GENERATE PAGE SELECTING CODE USING WREG COMMANDS PIC10 12 16 MCUs 4 53 1 Syntax pageselw label 4 53 2 Description An instruction to the linker to generate page selecting code to set the page bits to the page containing the designated 1abe1 Only one 1abe1 should be specified No operations can be performed on label 1abe1 must have been previously defined The linker will generate the appropriate page selecting code For 12 bit instruction width PIC10F some PIC12 PIC16 devices the appropriate bit set clear instructions on the STATUS register will be generated For 14 bit instruction width most PIC12 PIC16 devices MOVLW and MOVWF instructions will be generated to modify the PCLATH If the device contains only one page of program memory no code will be generated For PIC18 devices this command will do nothing as these devices do not use paging 4 53 3 Usage This dir
273. ore decimal digits 0123456789 A hexadecimal integer is h or H followed by one or more hexadecimal digits 0123456789abcdefABCDEF in single quotes Or a hexadecimal integer is Ox or OX followed by one or more hexadecimal digits 0123456789abcdefABCDEF An ASCII character is a or A followed by one character see Section B 2 ASCII Character Set in single quotes Or an ASCII character is one character in single quotes ARITHMETIC OPERATORS AND PRECEDENCE Arithmetic operators may be used with directives and their variables as specified in the table below Note These operators cannot be used with program variables They are for use with directives only The operator order in the table also corresponds to its precedence where the first operator has the highest precedence and the last operator has the lowest precedence Precedence refers to the order in which operators are executed in a code statement DS33014J page 42 2005 Microchip Technology Inc Expression Syntax and Operation TABLE 3 4 ARITHMETIC OPERATORS AND PRECEDENCE Operator Example Current Return program counter goto 3 Left Parenthesis 1 d 4 Right Parenthesis Length 1 256 Item NOT logical complement if J aoss b Negation 2 s complement 1 Length Complement flags flags low Return
274. orted Hendif endif GET 4 24 2 Description This directive marks the end of a conditional assembly block endif may be used inside a regular program block or macro 4 24 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation For every if directive used there must be a corresponding endif if and endif are not instructions but used for code assembly only DS33014J page 72 2005 Microchip Technology Inc Directives 4 24 4 See Also else if 4 24 5 Examples See the examples under if 4 25 endm END A MACRO DEFINITION 4 25 1 Syntax endm 4 25 2 Description Terminates a macro definition begun with macro 4 25 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation For every macro directive used there must be a corresponding endm 4 25 4 See Also macro exitm 4 25 5 Simple Example make table macro argl arg2 dw argl 0 null terminate table name res arg2 reserve storage endm 4 25 6 Application Example macro endm See this example under macro 4 206 endw END A while LOOP 4 26 4 Syntax Preferred endw Supported endw 4 26 2 Description endw terminates a while loop As long as the condition specified by the while directive remains true the source code between
275. ource file directory and 3 MPASM assembler executable directory There is a source file line limit expanded of 200 characters File names are limited to 8 3 format mpasm exe only 8 5 2 Directive Limitations Do not use includes in macros if directive limits Maximum nesting depth 16 include directive limits Maximum nesting depth 5 Maximum number of files 255 macro directive limits Maximum nesting depth 16 while directive limits Maximum nesting depth 8 Maximum number of lines per loop 100 Maximum iterations 256 DS33014J page 168 2005 Microchip Technology Inc AN ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Part 2 MPLINK Object Linker Chapter 9 MPLINK Linker Overview eeeeeeeeeeeeeee nennen eene 177 Chapter 10 Linker Interfaces nn 185 Chapter 11 Linker Scripts arinetan ii ii 187 Chapter 12 Linker Processing st isnnnnnennns 193 Chapter 13 Sample Applications nes 197 Chapter 14 Errors Warnings and Common Problems 219 2005 Microchip Technology Inc DS33014J page 169 Assembler Linker Librarian User s Guide NOTES DS33014J page 170 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 9 MPLINK Linker Overview 9 1 INTRODUCTION An overview of the MPLINK object linker and its capabilities is presented Topics covered in
276. pace IntL code 0x0018 VIntL bra 0x0218 Re map Interrupt vector to app s code space kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk Boot code 0x002A Boot loader executable code starts here Boot Start Logic to determine if bootloader executes or branch to user s code bra 0x022A Branch to user s application code end of boot loader code section kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk END 2005 Microchip Technology Inc DS33014J page 205 Assembler Linker Librarian User s Guide 13 5 15 MPASM Assembler Application Source Code In this example the application code is composed of several relocatable source files that are assembled and linked together during build time The relocatable reset and interrupt vector locations are defined in main asm and are assigned to a specific program memory location by the CODE directive main asm This is a sample of the startup portion of a main source code file that contains the relocated reset and interrupts and is the main entry point into the application kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk main asm Kee ce ce oe ce ce ck ce KER KEKE KKK KEK cce ce ce e ce ce ck cec ck ck cec ck oce KK ck ERRE k k EAA kkk KK KK KARA A AAA LIST P 18F8722 Hinclude P18cxxx inc kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk R_vectors code 0x200
277. panded source line exceeded 200 characters The maximum length of a source line after define and macro parameter substitution is 200 characters Note that define substitution does not include comments but macro parameter substitution does 149 Directive only allowed when generating an object file Certain directives such as global and extern only have meaning when a linkable object file is generated They cannot be used when generating absolute code 150 Labels must be defined in a code or data section when making an object file When generating a linkable object file all data and code address labels must be defined inside a data or code section Symbols defined by the equ and set directives can be defined outside of a section 151 Operand contains unresolvable labels or is too complex When generating an object file operands must be of the form high low relocatable address label offsef 152 Executable code and data must be defined in an appropriate section When generating a linkable object file all executable code and data declarations must be placed within appropriate sections 153 Page or Bank bits cannot be evaluated for the operand The operand of a pagesel banksel or bankisel directive must be a relocatable address label or a constant 154 Each object file section must be contiguous Object file sections except udata ovr sections cannot be stopped and restarted within a single source file To resolve this probl
278. per local vars table Cod file filename does not have a proper long symbol table Cod file filename does not have a proper memory map table Cod file filename does not have a proper name table Cod file filename does not have a proper symbol table Cod file filename does not have a properly formed first directory Cod file filename does not have a properly formed linked directory Could not open Cod file filename for reading Could not open Cod file filename for writing Could not write blockname block in Cod file filename Could not write directory in Cod file filename 14 10 HEX FILE ERRORS Selected hex format does not support byte addresses above 64kb use INHX32 format Your code addresses more than 64 Kbytes of program memory but your selected hex format cannot support this Switch to INHX32 format DS33014J page 222 2005 Microchip Technology Inc Errors Warnings and Common Problems Could not open hex file filename for writing The hex file was never created due to other errors or an exisiting hex file is write protected 14 11 COMMON PROBLEMS Although set up listing file properties with MPASM assembler directives none of these properties is appearing in my listing file Although MPASM assembler is often used with MPLINK object linker MPASM assembler directives are not supported in MPLINK linker scripts See Section 10 3 Command Line Interface for
279. pot a paging problem with this message turned off For more about errorlevel see Section 4 29 errorlevel Set Message Level A similar message is 302 for banking 307 Setting page bits Page bits are being set with the LCALL or LGOTO pseudo op 308 Warning level superseded by command line value The warning level was specified on the command line as well as in the source file The command line has precedence 309 Macro expansion superseded by command line Macro expansion was specified on the command line as well as in the source file The command line has precedence 310 Superseding current maximum RAM and RAM map The maxram directive has been used previously 311 Operand of HIGH operator was larger than H FFFF High byte of address returned by high directive was greater than OxFFFF 312 Page or Bank selection not needed for this device No code generated If a device contains only one ROM page or RAM bank no page or bank selection is required and any pagesel banksel or bankisel directives will not generate any code 313 CBLOCK constants will start with a value of 0 If the first cblock in the source file has no starting value specified this message will be generated 314 LFSR instruction is not supported on some versions of the 18Cxx2 devices See message 315 for more information 315 Please refer to Microchip document DS80058A for more details A downloadable pdf of this document PIC18CXX2 Silicon
280. pr2 START 0x200 END 0x2FF DATABANK NAME gpr3 START 0x300 END 0x3FF DATABANK NAME gpr4 START 0x400 END 0x4FF DATABANK NAME gpr5 START 0x500 END 0x5FF DATABANK NAME gpr6 START 0x600 END 0x6FF DATABANK NAME gpr7 START 0x700 END 0x7FF DATABANK NAME gpr8 START 0x800 END 0x8FF DATABANK NAME gpr9 START 0x900 END 0X9FF 2005 Microchip Technology Inc DS33014J page 211 Assembler Linker Librarian User s Guide DATABANK NAME gpr10 START 0xA00 END 0xAFF DATABANK NAME gpr11 START 0xB00 END 0xBFF DATABANK NAME gpri2 START 0xC00 END 0xCFF DATABANK NAME gpri3 START 0xD00 END 0xDFF DATABANK NAME gpri4 START 0xE00 END 0xEFF DATABANK NAME gpr15 START 0xF00 END 0xF5F ACCESSBANK NAME accesssfr START 0xF60 END 0xFFF PROTECTED SECTION NAME CONFIG ROM config SECTION NAME VECTORS ROM vectors SECTION NAME PROG ROM page SECTION NAME SRAM ROM xsram 13 6 9 MPASM Assembler Source Code This is a simple code example showing the definition of the external memory SRAM address at 20000h and how to write a 16 bit value to two consecutive memory locations using the table pointer register and table write instruction include lt p18F8722 inc gt define SRAM BASE ADDRS 0x20000 Base addrs for external memory device define SRAM END ADDRS Ox1FFFFF End addrs not required vectors code bra main prog code main Example how to write 0x55CC to first
281. program memory region or in an EE data memory region as in case of a PlCmicro device with EE data Flash include p16f877a inc Include standard header file for the selected device org 0x0000 The following code will be placed in reset address 0 goto Main Jump to an address whose label is Main org 0x0004 The following code will be placed in interrupt address 4 goto int routine Jump to an address whose label is int routine org 0x0010 The following code section will placed starting from address 10H Main A Write your main program here goto Main Loop back to Main org 0x0100 The following code section will be placed starting from address 100H int routine i Write your interrupt service routine here retfie Return from interrupt org 0x1000 You can create a data or character table starting from any address in program memory In this case the address is 1000h ch tbl1 da PICwithFLASH 6 program memory locations starting from 1000h will Sac A O A A AA Q c c en 2005 Microchip Technology Inc DS33014J page 101 Assembler Linker Librarian User s Guide be filled with six 14 bit packed numbers each representing two 7 bit ASCII characters org 0x2100 The absolue address 2100h is mapped to the 0000 location of EE data memory in PIC16Fxxx You can create a data or character table starting from any address in EE
282. put data latches are then cleared PORTA must be set up for digital I O as on power up several pins are analog Data direction registers TRISx are cleared to set port pins to outputs A loop named Loop is entered where the value of each port is increased indefinitely until the program is halted Finally the program is finished with an end 5 2 2 Commented Code Listing Toggles Port pins with count on PIC18F8720 PortA pins on POR RA5 RA3 0 analog inputs RA6 RA4 digital inputs PortB pins on POR RB7 0 digital inputs include p18f8720 inc Include file needed to reference data sheet names clrf PORTA Clear output data latches on Ports clrf PORTB movlw OxOF Configure Port A for digital I O movwf ADCON1 clrf TRISA Set data directon of Ports as outputs clrf TRISB Loop incf PORTA F Read PORTA add 1 and save back incf PORTB F Read PORTB add 1 and save back goto Loop Do this repeatedly count end All programs must have an end directive H A ROO ee DS33014J page 124 2005 Microchip Technology Inc Assembler Examples Tips and Tricks 5 3 EXAMPLE OF PORTB TOGGLE AND DELAY ROUTINES Directives highlighted in this example are udata res equ code banksel pagesel Items covered in
283. quence of bits that tells a central processing unit to perform a particular operation and can contain data to be used in the operation Internal Linkage A function or variable has internal linkage if it can not be accessed from outside the module in which it is defined International Organization for Standardization An organization that sets standards in many businesses and technologies including computing and communications Interrupt A signal to the CPU that suspends the execution of a running application and transfers control to an Interrupt Service Routine ISR so that the event may be processed Interrupt Handler A routine that processes special code when an interrupt occurs Interrupt Request An event which causes the processor to temporarily suspend normal instruction exe cution and to start executing an interrupt handler routine Some processors have several interrupt request events allowing different priority interrupts Interrupt Service Routine User generated code that is entered when an interrupt occurs The location of the code in program memory will usually depend on the type of interrupt that has occurred IRQ See Interrupt Request ISO See International Organization for Standardization ISR See Interrupt Service Routine Librarian See Archiver Library See Archive Linker A language tool that combines object files and libraries to create executable code resolving references from one module to
284. r just sends Vout goto AreYouThroughYet 0x05 goto CommDone 0x06 goto CommDone 0x07 2005 Microchip Technology Inc DS33014J page 105 Assembler Linker Librarian User s Guide 4 4 processor SET PROCESSOR TYPE 4 54 4 Syntax processor processor type 4 54 2 Description Sets the processor type to processor type 4 54 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is not generally used as the processor is set in MPLAB IDE Configure Device If it must be set in code use processor or the list directive option p to set the processor 4 54 4 See Also list 4 54 5 Simple Example processor 16f877a Sets processor to PIC16F877A 4 55 radix SPECIFY DEFAULT RADIX 4 55 1 Syntax radix default radix 4 55 2 Description Sets the default radix for data expressions The default radix is hex Valid radix values are hex hexadecimal base 16 dec decimal base 10 Oct octal base 8 You may also specify a radix using the 1ist directive For specifying the radix of constants see Section 3 4 Numeric Constants and Radix 4 55 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation For many programs the default radix hex is used and there is no need to set
285. r ROM data where a padding byte of zero is not appended to an odd number of bytes If 1abe1 is not specified the section is named code The starting address is initialized to ROM address or will be assigned at link time if no address is specified If ROM addressis specified it must be word aligned If padded data is desired use db Note Two sections in a source file may not have the same name 4 10 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation This directive is commonly used when storing data into program memory use with db or the EEPROM data memory use with de of a PIC18 device 4 10 4 See Also extern code global idata udata udata_acs udata_ovr udata_shr 4 10 5 Simple Example 00001 LIST P 18Cxx 00002 00003 packed code_pack 0x1F0 0001F0 01 02 03 00004 DB 1 225 3 0001F3 04 05 00005 DB 4 5 00006 00007 padded code 000000 0201 0003 00008 DB 125 33 000004 0504 00009 DB 4 5 00010 00011 END 2005 Microchip Technology Inc DS33014J page 57 Assembler Linker Librarian User s Guide 4 11 config SET PROCESSOR CONFIGURATION BITS Note configis preceded by two underline characters 4 11 1 Syntax Preferred _ config expr _ config addr expr PIC18 Only Note PIC18FXXJ devices do not support this directive Use config directive no underline characters Supported fuse
286. r browse to the location of this file The default location is listed in MPLAB IDE and Tools Installation 6 Select MPLIB Object Librarian mp1ib exe Under Location a path to the executable file should be displayed If no path is displayed enter one or browse to the location of this file The default location is listed in MPLAB IDE and Tools Installation 7 Click OK DS33014J page 10 2005 Microchip Technology Inc PlCmicro Language Tools and MPLAB IDE MPLAB IDE PROJECTS A project in MPLAB IDE is a group of files needed to build an application along with their associations to various build tools Below is a generic MPLAB IDE project FIGURE 2 PROJECT RELATIONSHIPS MPLIBTM librarian prog asm MPASMTM assembler MPLAB IDE Project xir iic NN l l l i l l e l l l l l l l l l l _ l SIMULATORS EMULATORS DEBUGGERS PROGRAMMERS source files ASSEMBLER COMPILER object files LIBRARIAN amp library file LINKER amp linker script file output files 2005 Microchip Technology Inc DS33014J page 11 Assembler Linker Librarian User s Guide In this MPLAB IDE project an assembly source file prog asm is shown with its associated assembler MPASM assembler MPLAB IDE will use this information to generate the object file pxog o for input into the MPLINK obje
287. r case letters digits symbols and control characters Assembler A language tool that translates assembly language source code into machine code Assembly Language A programming language that describes binary machine code in a symbolic form Asynchronous Stimulus Data generated to simulate external inputs to a simulator device Breakpoint Hardware An event whose execution will cause a halt 2005 Microchip Technology Inc DS33014J page 251 Assembler Linker Librarian User s Guide Breakpoint Software An address where execution of the firmware will halt Usually achieved by a special break instruction Build Compile and link all the source files for an application C A general purpose programming language which features economy of expression modern control flow and data structures and a rich set of operators Calibration Memory A special function register or registers used to hold values for calibration of a PICmicro microcontroller on board RC oscillator or other device peripherals COFF Common Object File Format An object file of this format contains machine code debugging and other information Command Line Interface A means of communication between a program and its user based solely on textual input and output Compiler A program that translates a source file written in a high level language into machine code Configuration Bits Special purpose bits programmed to set PICmicro microcontrolle
288. r modes of operation A configuration bit may or may not be preprogrammed Control Directives Directives in assembly language code that cause code to be included or omitted based on the assembly time value of a specified expression Cross Reference File A file that references a table of symbols and a list of files that references the symbol If the symbol is defined the first file listed is the location of the definition The remaining files contain references to the symbol Data Directives Data directives are those that control the assembler s allocation of program or data memory and provide a way to refer to data items symbolically that is by meaningful names Data Memory On Microchip MCU and DSC devices data memory RAM is comprised of General Purpose Registers GPRs and Special Function Registers SFRs Some devices also have EEPROM data memory Device Programmer A tool used to program electrically programmable semiconductor devices such as microcontrollers Digital Signal Controller A microcontroller device with digital signal processing capability i e Microchip dsPIC devices Directives Statements in source code that provide control of the language tool s operation DS33014J page 252 2005 Microchip Technology Inc Glossary Download Download is the process of sending data from a host to another device such as an emulator programmer or target board DSC See Digital Signal Controller
289. rate Page Selecting Code PIC10 12 16 MCUs 5 3 6 Banking In this example PORTB must be configured causing a switch to data memory bank 1 to access the TRISB register This change to bank 1 and subsequent return to bank 0 is easily accomplished using the banksel directive banksel TRISB Select TRISB Bank 1 clrf TRISB Set PortB as output banksel INTCON Select INTCON Bank 0 bsf INTCON GIE Enable Global Int s bsf INTCON TOIE Enable Timer0 Int Two other routines also use banksel to access the Option register OPTION REG For more on this directive see Section 4 7 banksel Generate Bank Selecting Code DS33014J page 130 2005 Microchip Technology Inc Assembler Examples Tips and Tricks 5 3 7 Interrupts The Delay 1 routine in this program uses the Timer 0 overflow interrupt as a timing mechanism Once the interrupt occurs the program branches to the interrupt vector Here code is located to jump to a location where interrupt handling code is found intrpt code 0x04 interrupt Vector goto ServInt Jump to service interrupt The interrupt handling code also known as the Interrupt Service Routine ISR is generated by the programmer to handle the specific requirements of the peripheral interrupt and the program In this case Timer 0 is stopped and its flag bit is cleared so it may be run again Then the program defined flag bit is cleared Finally retfie takes the program back to th
290. re AARGBO is MSB END EXAMPLE 6 11 RELOCATABLE CODE LIBRARY ROUTINE Input fixed point arguments in AARGBO and BARGBO Output product AARGxBARG in AARGBO AARGB1 Other comments truncated See AN617 PRR RRR RRR KERR kc ke ke echec ke ke he ke he ke e ke ke ke ke he ke e he ke ke che ke ke e he ke e he ke ke ce he kk he ke e kkk kkk e he ke ke ke he k k k Hinclude p16f877a inc Use any PIC16 device you like GLOBAL UMULO808L AARGBO AARGB1 BARGBO UDATA LOOPCOUNT RES 1 7 loops needed to complete routine AARGBO RES 1 MSB of result out AARGB1 RES 1 Operand A in 8 bits BARGBO RES L LSB of result out operand B in 8 bits Sac D m M c M P R 2005 Microchip Technology Inc DS33014J page 151 Assembler Linker Librarian User s Guide CODE UMULO808L movlw 0x08 movwf LOOPCOUNT movf AARGBO W LOOPUMO808A rff BARGBO F btfsc STATUS C goto LUM0808NAP decfsz LOOPCOUNT F goto LOOPUMO808A clrf AARGBO retlw 0x00 LUMO808NAP bcf STATUS C goto LUMO808NA LOOPUMO808 rrf BARGBO F btfsc STATUS C addwf AARGBO F LUMO808NA rrf AARGBO F rrt AARGB1 F decfsz LOOPCOUNT F goto LOOPUMO808 retlw 0 END EEE
291. recedence is the same for the low high and upper operands which apply to sections See Section 6 4 Low High and Upper Operands for more information 2 These operators can only be used on a line by themselves they cannot be embedded within other expression evaluations 2005 Microchip Technology Inc DS33014J page 43 Assembler Linker Librarian User s Guide NOTES DS33014J page 44 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 4 Directives 4 1 INTRODUCTION Directives are assembler commands that appear in the source code but are not usually translated directly into opcodes They are used to control the assembler its input output and data allocation Many of the assembler directives have alternate names and formats These may exist to provide backward compatibility with previous assemblers from Microchip and to be compatible with individual programming practices If portable code is desired it is recommended that programs be written using the specifications contained here Although MPASM assembler is often used with MPLINK object linker MPASM assembler directives are not supported in MPLINK linker scripts See MPLINK object linker documentation for more information on linker options to control listing and hex file output Information on individual directives includes syntax description usage and related directives as well as simple and in some cases
292. rective may be useful when exploring a small range of code with many macros in it 4 31 4 See Also macro noexpand 4 32 extern DECLARE AN EXTERNALLY DEFINED LABEL 4 32 4 Syntax extern label label 4 32 2 Description This directive declares symbol names that may be used in the current module but are defined as global in a different module The extern statement must be included before the 1abe1 is used At least one label must be specified on the line If 1abe1 is defined in the current module MPASM assembler will generate a duplicate label error 4 32 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation As soon as you have more than one file in your project you may use this directive extern Will be used in a file when a label usually a variable is used by that file global will be used in another file so that the label may be seen by other files You must use both directives as specified or the label will not be visible to other files 4 32 4 See Also global idata udata udata acs udata ovr udata shr 4 32 5 Simple Example extern Function call Function DS33014J page 80 2005 Microchip Technology Inc Directives 4 32 6 Application Example extern global The program main asm along with sub asm demonstrate the global and extern directives which make it possible to use symbols in modules other than
293. reference filename Listing File A listing file sourcename 1st is created by default For more information on this file type see Section 1 7 3 Listing File Ist To turn the listing file off use the keyboard arrow keys to move to the field and press Enter to change it to No The listing filename can be changed by pressing the lt Tab gt key to move to the shaded area and typing a new name Wild cards are not allowed in the listing filename Hex Dump Type Set this value to generate the desired hex file format For more information on this format see Section 1 7 5 Hex File Formats hex hxl hxh Changing this value is accomplished by moving to the field with the keyboard arrow keys and pressing the Enter key to scroll through the available options To change the hex filename press the Tab key to move the shaded area and type in the new name Assemble to Object File Enabling this option will generate the relocatable object code that can be input to the linker and suppress generation of the hex file For more information on this file type see Section 1 7 8 Object File 0 To turn the object file on use the keyboard arrow keys to move to the field and press Enter to change it to Yes The object filename can be changed by pressing the lt Tab gt key to move to the shaded area and typing a new name Wild cards are not allowed in the object filename DS33014J page 34 2005 M
294. register 0 to 7 d Destination select bit d 0 store result in WREG d 1 store result in file register f default Fast Call Return mode select bit S 0 do not update into from shadow registers default S 1 certain registers loaded into from shadow registers Fast mode Bit values as opposed to Hex value Named Registers BSR Bank Select Register Used to select the current RAM bank FSR File Select Register PCL Program Counter Low Byte 2005 Microchip Technology Inc DS33014J page 243 Assembler Linker Librarian User s Guide Field Description PCH Program Counter High Byte PCLATH Program Counter High Byte Latch PCLATU Program Counter Upper Byte Latch PRODH Product of Multiply High Byte PRODL Product of Multiply Low Byte STATUS STATUS Register TABLAT 8 bit Table Latch TBLPTR 21 bit Table Pointer points to a Program Memory location WREG Working register accumulator Named Bits C DC Z OV N ALU Status bits Carry Digit Carry Zero Overflow Negative TO Time out bit PD Power down bit PEIE Peripheral Interrupt Enable bit GIE GIEL H Global Interrupt Enable bit s Named Device Features MCLR Master clear device reset PC Program Counter TOS Top of Stack WDT Watchdog Timer Misc Descriptors NP Contents gt Assigned to lt gt Register bit
295. rogramming house as this helps insure the device is configured correctly when programmed Place configuration bit assignments at the beginning of your code Use the configuration options setting value pairs listed in the standard include inc file or the addendum The config directive can be used multiple times in the source code but an error will be generated if the same bit is assigned a value more than once i e CONFIG CPO OFF WDT ON CONFIG CPO ON An error will be issued since CPO is assigned twice 4 12 4 See Also __config _ idlocs list processor 4 125 Simple Example Hinclude p18f452 inc Include standard header file for the selected device code protect disabled CONFIG CPO OFF Oscillator switch enabled RC oscillator with OSC2 as I O pin CONFIG OSCS ON OSC LP Brown OutReset enabled BOR Voltage is 2 5v CONFIG BOR ON BORV 25 Watch Dog Timer enable Watch Dog Timer PostScaler count 1 128 CONFIG WDT ON WDTPS 128 CCP2 pin Mux enabled CONFIG CCP2MUX ON Stack over underflow Reset enabled CONFIG STVR ON 4 13 constant DECLARE SYMBOL CONSTANT 4 13 4 Syntax constant label expr label expr DS33014J page 60 2005 Microchip Technology Inc Directives 4 13 2 Description Creates symbols for use in MPASM assembler expressions Constants may not be reset after having once been initialized and the expression must be fully resolvable at the time of the assignment Th
296. rom File BTFSC 3 1 Z DECF f d TSTF f Test File MOVF f Z A 6 KEY TO PIC18 DEVICE INSTRUCTION SET Field Description Register Files dest Destination either the WREG register or the specified register file location See f Register file address f 8 bit 0x00 to OxFF 12 bit 0x000 to OxFFF This is the source address 12 bit 0x000 to OxFFF This is the destination address 0 1 or 2 for FSR number x Don t care 0 or 1 The assembler will generate code with x 0 It is the recommended form of use for compatibility with all Microchip software tools Zz Indirect addressing offset z 7 bit offset value for indirect addressing of register files source z 7 bit offset value for indirect addressing of register files destination Literals k Literal field constant data or label k 4 bit kk 8 bit kkk 12 bit Offsets Increments Decrements n The relative address 2 s complement number for relative branch instructions or the direct address for Call Branch and Return instructions The mode of the TBLPTR register for the table read and table writes Only used with table read TBLRD and table write TBLWT instructions No Change to register Post Increment register Post Decrement register Pre Increment register Bits a RAM access bit a 0 RAM location in Access RAM BSR register is ignored a 1 RAM bank is specified by BSR register default b Bit address within an 8 bit file
297. rs to an emulator output signal that can be generated at any address or address range and is independent of the trace and breakpoint settings Any number of trigger output points can be set Uninitialized Data Data which is defined without an initial value In C int myVar defines a variable which will reside in an uninitialized data section Upload The Upload function transfers data from a tool such as an emulator or programmer to the host PC or from the target board to the emulator Warning An alert that is provided to warn you of a situation that would cause physical damage to a device software file or equipment Watch Variable A variable that you may monitor during a debugging session in a watch window DS33014J page 262 O 2005 Microchip Technology Inc Glossary Watch Window Watch windows contain a list of watch variables that are updated at each breakpoint Watchdog Timer A timer on a PICmicro microcontroller that resets the processor after a selectable length of time The WDT is enabled or disabled and set up using configuration bits WDT See Watchdog Timer Workbook For MPLAB SIM stimulator a setup for generation of SCL stimulus 2005 Microchip Technology Inc DS33014J page 263 Assembler Linker Librarian User s Guide NOTES DS33014J page 264 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Index Symbols C Hd NN t de den eae ed it 68
298. s 1 From the MPLAB IDE menu bar select Project gt Set Language Tool Locations to open a dialog to set check language tool executable location 2 Inthe dialog under Registered Tools select Microchip MPASM Toolsuite Click the to expand 3 Select Executables Click the to expand 4 Select MPASM Assembler mpasmwin exe Under Location a path to the mpasmwin exe file should be displayed If no path is displayed enter one or browse to the location of this file By default it is located at C Program Files Microchip MPASM Suite mpasmwin exe 5 Click OK 6 From the MPLAB IDE menu bar select Project Quickbuild to assemble the specified asm file using the MPASM assembler 2005 Microchip Technology Inc DS33014J page 31 Assembler Linker Librarian User s Guide 2 3 WINDOWS INTERFACE MPASM assembler for Windows provides a graphical interface for setting assembler options It is invoked by executing mpasmwin exe in Windows Explorer or from a command prompt FIGURE 2 1 MPASM ASSEMBLER WINDOWS SHELL INTERFACE EIMPASM v03 60 Microchip Technology Inc ioj xl Source File Name Browse Options MICROCHIP Radix Warning Level Hex Output Generated Files Default Default Default Error File C Hexadecimal C All Messages C INHXEM v List File Decimal C Warnings and Errors C INHX8S Cross Reference File C Octal C Errors Only C INHX32 Object File r Macro Expansion Procae
299. s occorre rada 166 8 5 Assembler Limitations ss 168 Part 2 MPLINK Object Linker Chapter 9 MPLINK Linker Overview Chapter 10 Linker Interfaces Chapter 11 Linker Scripts Chapter 12 Linker Processing 9 1 Introduction iii 171 9 2 MPLINK Linker Defined ss 171 9 3 How MPLINK Linker Works ss 171 9 4 How MPLINK Linker Helps You sssemmMMMMMRHHHIHe 172 9 5 Linker Platforms SUppOF Bed desierunt ded ab rt Ree o nad de 172 9 6 Linker Operation cal a mnt kates atit 172 9 7 Linker Input Output Files sachant pa nad eben pcc x ex Rd p oti 173 10 1 Introduction iii 179 10 2 MPLAB IDE Interface iii 179 10 3 Command Line Interface iii 179 10 4 Command Line Example issu 180 TAS INTO AUCHON RER RE Rer gott esent pae tesis 181 11 2 Standard Linker Scripts 2 AR A NA xp I osa 181 11 3 Linker Script Command Line Information seesesseeesse 182 11 4 Linker Script Caveats cdt RD atte er ete 183 11 5 Memory Region Definition orta taire 183 11 6 Logical Section Definition 5s oco ria 185 11 7S TACK DefInitiGn z eicere tc 186 12 Introducir a ri 187 12 2 Linker Processing Overview us 187 12 3 Linker Allocation Algorithme 188 12 4 Relocation Example teta etr a esa Pads inde teer au o fs 189 12 5 Initialized Data iii 190 12 6 Reserved Section Names ssssssee eene nennen nnne 190 2005 Microchip Technology Inc Table of Contents Chapter 13 Sample Applications 1331 dnttOglellOls
300. s For example CALL destinations on the PIC16C5x family must be in the lower half of the page 121 Illegal label Labels are not allowed on certain directive lines Simply put the label on its own line above the directive Also high low page and bank are not allowed as labels 122 Illegal opcode Token is not a valid opcode 123 Illegal directive Directive is not allowed for the selected processor for example the idlocs directive on devices with ID locations 124 Illegal argument An illegal directive argument for example list foobar 125 Illegal condition A bad conditional assembly For example an unmatched endi f 126 Argument out of range Opcode or directive argument out of the valid range for example TRIS 10 127 Too many arguments Too many arguments specified for a macro call 128 Missing argument s Not enough arguments for a macro call or an opcode 129 Expected Expected a certain type of argument The expected list will be provided 2005 Microchip Technology Inc DS33014J page 159 Assembler Linker Librarian User s Guide 130 Processor type previously defined A different family of processor is being selected 131 Processor type is undefined Code is being generated before the processor has been defined Note that until the processor is defined the opcode set is not known 132 Unknown processor The selected processor is not a valid processor 133 Hex file format INHX32 required An
301. s at start up The names of the initializer sections created by the linker are the same as the initialized data sections with a i appended For example if an input object module contains an initialized data section named idata_main o the linker will create a section in program memory with the name idata main o i which contains the data In addition to creating initializer sections the linker creates a section named cinit in program memory The cinit section contains a table with entries for each initialized data section Each entry is a triple which specifies where in program memory the initializer section begins where in data memory the initialized data section begins and how many bytes are in the initialized data section The boot code accesses this table and copies the data from ROM to RAM 12 6 RESERVED SECTION NAMES Both the MPASM assembler and the MPLAB C18 C compiler have reserved names for certain types of sections Please see the documentation for these tools to ensure that you do not use a reserved name for your own section The linker will be unable to generate the application if there is a section naming conflict DS33014J page 190 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 13 Sample Applications 13 1 INTRODUCTION You can learn the basics of how to use MPLINK linker from the four sample applications listed below These sample applications can be used as temp
302. s expr 4 11 2 Description Sets the processor s configuration bits Before this directive is used the processor must be declared through the command line the 1ist directive the processor directive or Configure Select Device if using MPLAB IDE Refer to individual PICmicro microcontroller data sheets for a description of the configuration bits PIC10 12 16 MCUs Sets the processor s configuration bits to the value described by expr PIC18 MCUs For the address of a valid configuration byte specified by addr sets the configuration bits to the value described by expr Note Configuration bits must be listed in ascending order Although this directive may be used to set configuration bits for PIC18 MCU devices it is recommended that you use the conf ig directive no underline characters For PIC18FXXJ devices you must use the config directive Note Donotmix config and config directives in the same code 4 113 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is placed in source code so that when the code is assembled into a hex file the configuration values are preset to desired values in your application This is useful when giving your files to a third party programming house as this helps insure the device is configured correctly when programmed Place configuration bit assignments at
303. s of a register with the working register is to use three XORWF instructions It requires no temporary registers and three instructions Here s an example W REG Instruction 10101100 01011100 XORWF REG F 10101100 11110000 XORWF REG W 01011100 11110000 XORWF REG F 01011100 10101100 Result 5 9 5 TIP 5 Bit Shifting Using Carry Bit Rotate a byte through carry without using RAM variable for loop count Easily adapted to serial interface transmit routines Carry bit is cleared except last cycle and the cycle repeats until the zero bit sets indicating the end list p 12f629 include p12f629 inc buffer equ 0x20 bsf STATUS C Set end of loop flag rif buffer F Place first bit into C bcf GPIO Dout Precondition output btfsc STATUS C Check data 0 or 1 bsf GPIO Dout bcf STATUS C Clear data in C rit buffer F Place next bit into C movf buffer F Force Z bit btfss STATUS Z Exit goto Send Loop 2005 Microchip Technology Inc DS33014J page 141 Assembler Linker Librarian User s Guide NOTES DS33014J page 142 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 6 Relocatable Objects 6 1 INTRODUCTION MPASM assembler used with MPLINK object linker has the ability to generate and link precompiled object modules Writing source code that will be assembled to an object module is slightly different from writing code used to generate an executa
304. s often used to define variable address location names Do not use cblock or equ to define variable location names for relocatable code 4 8 4 See Also endc equ DS33014J page 54 2005 Microchip Technology Inc Directives 4 8 5 Simple Example cblock 0x20 name 1 will be assigned 20 name 1 name 2 name 2 21 and so on name 3 name 4 name 4 is assigned 23 endc cblock 0x30 TwoByteVar 0 TwoByteHigh TwoByteLow TwoByteVar 0x30 TwoByteHigh 0x30 TwoByteLow 0x31 Queue QUEUE SIZE QueueHead QueueTail Double1 2 Double2 2 endc 4 8 6 Application Example cblock endc This example shows the usage of CBLOCK and ENDC directives for defining constants or variables in data memory space The same directives can be used for program memory space also The program calculates the perimeter of a rectangle Length and width of the rectangle will be stored in buffers addressed by 1ength 22H and width 23H The calculated perimeter will be stored in the double precision buffer addressed by perimeter i e 20H and 21H include p16f877a inc Include standard header file for the selected device CBLOCK 0x20 Define a block of variables starting at 20H in data memory perimeter 2 The label perimeter is 2 bytes wide Address 20H and 21H is assigned to the label perimeter length Address 22H is assigned to the label length width Address 23H is assigned to the label width ENDC This direc
305. s power is off NOP No Operation An instruction that has no effect when executed except to advance the program counter Object Code The machine code generated by an assembler or compiler Object File A file containing machine code and possibly debug information It may be immediately executable or it may be relocatable requiring linking with other object files e g libraries to produce a complete executable program Object File Directives Directives that are used only when creating an object file Off Chip Memory Off chip memory refers to the memory selection option for the PIC17 or PIC18 device where memory may reside on the target board or where all program memory may be supplied by the Emulator Opcodes Operational Codes See Mnemonics Operators Symbols like the plus sign and the minus sign that are used when forming well defined expressions Each operator has an assigned precedence that is used to determine order of evaluation OTP One Time Programmable EPROM devices that are not in windowed packages Since EPROM needs ultraviolet light to erase its memory only windowed devices are erasable DS33014J page 258 2005 Microchip Technology Inc Glossary Pass Counter A counter that decrements each time an event such as the execution of an instruction at a particular address occurs When the pass count value reaches zero the event is satisfied You can assign the Pass Counter to br
306. s to the linker command file search path LKRPATH lkrpath where 1krpathis a semicolon delimited list of directories EXAMPLE 11 2 LKRPATH EXAMPLE To append the current directory s parent and the directory C PROJECTS SCRIPTS to the linker command file search path the following line should be added to the linker command file LKRPATH C PROJECTS SCRIPTS 11 33 FILES The following directive specifies object or library files for linking FILES objfile libfile objfile libfile where objfile libfileis either an object or library file Note More than one object or library file can be specified in a single FILES directive EXAMPLE 11 3 FILES EXAMPLE To specify that the object module main o be linked with the library file math 1ib the following line should be added to the linker command file FILES main o math lib A A As AAA AA DS33014J page 182 O 2005 Microchip Technology Inc Linker Scripts 11 3 4 INCLUDE The following directive includes an additional linker command file INCLUDE cmdfile where cmdfile is the name of the linker command file to include EXAMPLE 11 4 INCLUDE EXAMPLE To include the linker command file named mylink lkr the following line should be added to the linker command file INCLUDE mylink lkr 11 4 LINKER SCRIPT CAVEATS Some linker script caveats You may need to modify the linker script files included with MPLINK linker before using
307. s used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive is not an instruction but used to control how code is assembled not how it behaves at run time Use this directive for conditional assembly or to check for a condition such as to generate an error message 4 38 4 See Also else endif DS33014J page 88 2005 Microchip Technology Inc Directives 4 38 5 Simple Example if version 100 check current version movlw 0x0a movwf io 1 else movlw 0x0la movwf io 2 endif 4 38 6 Application Example if else endif This program demonstrates the utility of 1 e1se and endif assembly directives include p16f877a inc Include standard header file for the selected device variable cfab variable used to define required configuration of PORTA amp PORTB cfab set 1 Set config to decimal 1 RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start 2PUSUart PGM CODE This is the begining of the code section named PGM It is a relocatable code section since no absolute address is given along with directive CODE start banksel TRISA if cfab 0x0 If config 0x0 is true clrw assemble the mnemonics up to movwf TRISA the directive else Set up PORTA
308. se number is 207 label of this directive is also not at column 1 but no warning is displayed printed This enables warning whose number is 207 Display print only errors label of this directive is not at column 1 This will generate a warning number 207 Warning 207 will NOT display print for error level 2 errorlevel 1 group2 var2 res 1 RST CODE 0x0 pagesel start goto start INTRT CODE 0x4 pagesel goto service int service int Display print warnings and errors label of this directive is not at column 1 This will generate a warning number 207 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST Jumps to the location labelled start The code section named INTRT is placed at 0x4 The next two instructions are placed in code section INTRT Label service int is not defined Hence this generates error 113 2005 Microchip Technology Inc DS33014J page 77 Assembler Linker Librarian User s Guide Error 113 will always display print regardless of error level PGM CODE This is the begining of the code section named PGM It is a relocatable code section since no absolute address is given along with directive CODE start movwf groupl varl goto Go to current line loop here end 4 30 exitm EXIT FROM A MACRO 4 30 4 Syntax exitm 4 30 2 Descr
309. sed and modified as needed may be found with MPLINK linker sample application examples Note This directive is not available for 12 bit instruction width PIC10 some PIC12 PIC16 devices The res db and dw directives may be used to reserve space for variables res will generate an initial value of zero db will initialize successive bytes of RAM dw will initialize successive bytes of RAM one word at a time in low byte high byte order 4 35 3 Usage This directive is used in the following types of code relocatable For information on types of code see Section 1 6 Assembler Operation Use this directive to initialize your variables or use a udata directive and then initialize your variables with values in code It is recommended that you always initialize your variables Relying on RAM initialization can cause problems especially when using an emulator as behavioral differences between the emulator and the actual part may occur 4 35 4 See Also extern global udata udata acs udata ovr udata shr 4 35 5 Simple Example idata LimitL dw 0 LimitH dw D 300 Gain dw D 5 Flags db 0 String db Hi there 4 35 6 Application Example idata This directive reserves RAM locations for variables and directs the linker to generate a lookup table that may be used to initialize the variables specified in this section The Starting Address of the lookup table can be obtained from the Map map file If you don t specify a value
310. sed for variables that can be declared at the same address as other variables in the same module or in other linked modules A typical use of this section is for temporary variables See 4 63 udata ovr Begin an Object File Overlaid Uninitialized Data Section udata shr Uninitialized shared data This data section is used for variables that will be placed in RAM of PIC12 16 devices that is unbanked or shared across all banks See 4 64 udata shr Begin an Object File Shared Uninitialized Data Section PIC12 16 MCUs idata Initialized data The linker will generate a lookup table that can be used to initialize the variables in this section to the specified values When linked with MPLAB C17 or C18 code these locations will be initialized during execution of the startup code The locations reserved by this section can be accessed only by the labels defined in this section or by indirect accesses See 4 35 idata Begin an Object File Initialized Data Section The following example shows how a data declaration might be created EXAMPLE 6 4 RAM ALLOCATION Absolute Code Use cblock to define variable register locations see 4 8 cblock Define a Block of Constants Variable values will need to be specified in code cblock 0x20 HistoryVector Must be initialized to 0 InputGain OutputGain Control loop gains Templ Temp2 Temp3 Used for internal calculations endc Equivalent Relocatable Code Use data declara
311. sed to separate pieces of a source line White space should be used to make your code easier for people to read Unless within character constants any white space means the same as exactly one space DS33014J page 24 2005 Microchip Technology Inc MPASM Assembler Overview EXAMPLE 1 1 ABSOLUTE MPASM ASSEMBLER SOURCE CODE SHOWS MULTIPLE OPERANDS Mnemonics Directives Labels Macros Operands Comments y y y y list p 18f452 Hinclude p18f452 inc Dest equ 0x0B Define constant org 0x0000 Reset vector goto Start org 0x0020 Begin program Start moviw Ox0A movwf Dest bcf Dest 3 This line uses 2 operands goto Start end 1 7 1 1 LABELS A label is used to represent a line or group of code or a constant value It is needed for branching instructions Example 1 1 Labels should start in column 1 They may be followed by a colon space tab or the end of line Labels must begin with an alpha character or an under bar and may contain alphanumeric characters the under bar and the question mark Labels must not begin with two leading underscores e g config begin with a leading underscore and number e g 2NDLOOP be an assembler reserved word see Section 3 3 Reserved Words and Section Names Labels may be up to 32 characters long By default they are case sensitive but case sensitivity may be overridden by a command line option c If a colon is used when defining a label it is treated as
312. solve section reference symName in file filename The symbol symName is an external reference No input module defines this symbol If the symbol is defined in a library module ensure that the library module is included on the command line or in the linker command file using the FILES directive Could not resolve symbol symName in file filename The symbol symName is an external reference No input module defines this symbol If the symbol is defined in a library module ensure that the library module is included on the command line or in the linker command file using the FILES directive Duplicate definition of memory nemName All CODEPAGE and DATABANK directives must have unique NAME attributes Duplicate definitions of SECTION secName Each SECTION directive must have unique NAME attributes Remove duplicate definitions File filename section secName performs a call to symbol symName which is not in the lower half of a page For 12 bit devices the program counter PC bit 8 is cleared in the CALL instruction or any modify PCL instruction Therefore all subroutine calls or computed jumps are limited to the first 256 locations of any program memory page 512 words long 2005 Microchip Technology Inc DS33014J page 215 Assembler Linker Librarian User s Guide Inconsistent length definitions of SHAREBANK memName All SHAREBANK definitions which have the same NAME attribute m
313. sor Modified 2005 02 02 for MPLAB C18 application code examples LIBPATH FILES c018i o FILES clib lib FILES p18f8722 1ib CODEPAGE NAME vectors START 0x0 END 0x29 PROTECTED CODEPAGE NAME boot START 0x2A END 0x7FF PROTECTED CODEPAGE NAME rm vectors START 0x800 END 0x829 PROTECTED CODEPAGE NAME user code START 0x82A END 0x1FFFF CODEPAGE NAME idlocs START 0x200000 END 0x200007 PROTECTED CODEPAGE NAME config START 0x300000 END 0x30000D PROTECTED CODEPAGE NAME devid START 0x3FFFFE END 0x3FFFFF PROTECTED CODEPAGE NAME eedata START 0xF00000 END 0xF003FF PROTECTED DS33014J page 200 O 2005 Microchip Technology Inc Sample Applications 13 5 6 MPLAB C18 Application Source Code The MPLAB C18 application code can be composed of one or more aggregate relocatable C source files that are compiled and linked together during build time In the code snippet shown below the source code file uses the pragma code directive to instruct the linker to place the relocated reset and interrupt vectors at the appropriate memory locations main function must be included as this is called from the MPLAB C18 startup code that is added during the link process The linker automatically includes this MPLAB C18 initialization code provided in file co18i c and must be accessed by the application code through an in line assembly goto instruction shown below include lt p18cxxx h gt
314. sor Iv Case Sensitive Default Default y m C On Tab Size g 4 c of Extended Mode Extra Options X Exit Iv Save Settings on Exit Help Select a source file by typing in the name or using the Browse button Set the various options as described below Default options are read from the source file Then click Assemble to assemble the source file Note When MPASM assembler for Windows is invoked through MPLAB IDE this options screen is not available Use the MPASM Assembler tab of the Build Options dialog in MPLAB IDE Project gt Build Options gt Project to set options Option Description Radix Override any source file radix settings Reference Section 4 42 list Listing Options Section 4 55 radix Specify Default Radix Section 3 4 Numeric Constants and Radix Warning Level Override any source file message level settings Reference Section 4 47 messg Create User Defined Message Hex Output Override any source file hex file format settings Reference Section 1 7 5 Hex File Formats hex hxl hxh Generated Files Enable disable various output files Reference Section 1 7 Assembler Input Output Files Case Sensitivity Enable disable case sensitivity If enabled the assembler will distinguish between uppercase and lowercase letters Tab Size Set the list file tab size Reference Section 1 7 3 Listing File Ist Macro Expansion Override any sour
315. specified it will be given the value of the expr If no org is specified code generation will begin at address zero For PIC18 devices only even numbered expr values are allowed When generating an object file the org directive is interpreted as introducing an absolute CODE section with an internally generated name For example L1 org 0x200 is interpreted as Scnname CODE 0x200 L1 where scnname is generated by the assembler and will be distinct from every name previously generated in this context 4 50 3 Usage This directive is used in the following types of code absolute For information on types of code see Section 1 6 Assembler Operation DS33014J page 100 2005 Microchip Technology Inc Directives org is commonly used in single file assembly programs whenever code needs to be placed at a particular location Commonly used values are 0x0 reset 0x4 PIC16 device interrupt vector 0x8 PIC18 device high priority interrupt vector and 0x18 PIC18 device low priority interrupt vector 4 50 4 See Also fill res end 4 50 5 Simple Example int 1 org 0x20 Vector 20 code goes here int 2 org int 1 0x10 Vector 30 code goes here 4 50 6 PIC16 Application Example org This example shows the usage of the org directive Code generation begins at an address specified by org address The origin of a data table also can be specified by this directive A data table may be placed either in a
316. ssembler Overview LA TATOO UCTON ioter et rne Ei x Cor rodeo race ater a Er RARE TT 21 1 2 MPASM Assembler Defined sise 21 1 3 How MPASM Assembler Helps You sese 21 1 4 Assembler Migration Path 22 1 5 Assembler Compatibility Issues ooooocccccccconicooocnnncconanannonnncnnnnnononannnonnnos 22 1 6 Assemibler Operations iii disce pnt pd o SE dx Rod ta Ra ERR RI RE Roa e piv ada else ees 22 1 7 Assembler Input Output Files oooooocococcncccnonoooooncnnccnnnanonarcncnnnnnnnnnnnnnnnnnos 24 Chapter 2 Assembler Interfaces QA Introduction carere ere Ei aeo e Fal EL pa ar ED Ec C d 31 2 MPLABJDE Interface d eot daa teo ER date b t ut oe 31 2 3 Windows Interface sise 32 2 4 Command Shell Interface reiini anniina anaa aaa aTa a aA A a 33 2 5 Command Line Interface inserer 35 2 6 Troubleshooting oso rre Redes pb 37 Chapter 3 Expression Syntax and Operation dl IntrodlctiOnusss ett t e is 39 3 2 TOXU SI ecco ito o aat st ete tk 39 3 3 Reserved Words and Section Names LL 41 3 4 Numeric Constants and Radix sisi 41 3 5 Arithmetic Operators and Precedence sse 42 Chapter 4 Directives AL IntrodetlOn dope peer e icine tease t Pr E 45 Ae DIRGCUVES DY TO en ne tin eee nt ne 45 4 8 access ovr Begin an Object File Overlay Section in Access RAM TPIG18 MCUS eee rtr eere menta Pci tera ee rne origin 48 4 4 badram Identify Unimplemented RAM seeeeeeeeese 48 4 5 ba
317. ssembler help screen mpasm exe only 1 path On Enable Disable Set Path for list file 1 Enable 1 Enable 1 Disable 1 path Enable specify path See Section 1 7 3 Listing File Ist for more information m On Enable Disable macro expansion See Section 4 31 expand Expand Macro Listing for more information 2005 Microchip Technology Inc DS33014J page 35 Assembler Linker Librarian User s Guide Option Default Description o path Off Enable Disable Set Path for object file o Enable o Enable o Disable o path Enable specify path See Section 1 7 8 Object File 0 for more information pprocessor type None Set the processor type where processor type is a PlCmicro MCU device e g PIC18F452 al 1 Off Enable Disable quiet mode suppress screen output rradix Hex Defines default radix where radix is one of HEX DEC OCT See Section 4 42 list Listing Options or Section 4 55 radix Specify Default Radix for more information t 8 Set the size of tabs in the list file See Section 1 7 3 Listing File Ist for more information wvalue 0 Set message level where value is one of 0 1 2 0 all messages 1 errors and warnings 2 errors only See Section 4 47 messg Create User Defined Message for more information X path Off Enable Disable Set Path for cross reference file x Enable x Enable
318. ssg CREATE USER DEFINED MESSAGE 4 47 4 Syntax messg message text 4 47 2 Description Causes an informational message to be printed in the listing file The message text can be up to 80 characters Issuing a messg directive does not set any error return codes DS33014J page 98 2005 Microchip Technology Inc Directives 4 47 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation This directive may be used to generate any desired message It can be useful with conditional assembly to verify in the assembled program which code was built 4 47 4 See Also error 4 47 5 Simple Example mssg macro macro messg mssg macro 001 invoked without argument endm 4 47 6 Application Example messg This program demonstrates the messg assembler directive which sets a message to be printed in the listing file and error file Hinclude p16f877a inc Include standard header file for the selected device variable baudrate variable used to define required baud rate baudrate set D 5600 Enter the required value of baud rate here if baudrate D 1200 amp amp baudrate D 2400 amp amp baudrate D 4800 amp amp baudrate D 9600 amp amp baudrate D 19200 error Selected baud rate is not supported messg only baud rates 1200 2400 4800 9600 19200 Hz amp amp are supported endif
319. sss toe terr a te Dentaire 191 13 2 How to Build the Sample Applications ccoooooooccccncccnnonononnncnnnnnnnnnnnnnnnos 191 13 3 Sample Application 1 Modifying the Linker Script 193 13 4 Sample Application 2 Placing Code and Setting CONFIG Bits 195 13 5 Sample Application 3 Using a Boot Loader sssessesessess 198 13 6 Sample Application 4 Configuring External Memory 208 Chapter 14 Errors Warnings and Common Problems 14 MIntroductionusc imt teri ter E PO p pectet a Po E ita 213 14 2 Linker Parse Errors uci ts P Ts 213 14 3 Linker Errors iii 215 144 Linker Warnings oca pori eigenen rota diee Sev Debs ic Pee a 220 14 5 Library File EIOS tte 220 14 6 GOFE Eile EHOrS 2 o o eS 221 14 7 COFF To COD Conversion Errors essem 222 14 8 COFF To COD Converter Warnings eem 222 14 9 COD File Errors 4 t tette a 222 T4 TO Hex Elle EIOS usara E Ee be eee teh EXE ine oon d Coa Peta ntc ens 222 14 11 Common Problems sise 223 Part 3 MPLIB Object Librarian Chapter 15 MPLIB Librarian Overview introducidas 227 15 2 What is MPLIB Librarian iii 227 15 3 How MPLIB Librarian Works occccooonccnccccoccnccccnoononnononconocnonccnnnnnnncnononcnonos 227 15 4 How MPLIB Librarian Helps YOU reo ptite deberent 228 15 5 Libranan OBESA O to sence OR Ru teen ag ce vein ie ions 228 15 6 Librarian I
320. st is focused on the MPLAB IDE MPLAB IDE Project Manager MPLAB Editor and MPLAB SIM simulator as well as general editing and debugging features Programmers The latest information on Microchip programmers These include the MPLAB PM3 and PRO MATE II device programmers and the PICSTART Plus and PICkitTM 1 development programmers DS33014J page 6 2005 Microchip Technology Inc Preface CUSTOMER SUPPORT Users of Microchip products can receive assistance through several channels Distributor or Representative Local Sales Office Field Application Engineer FAE Technical Support Customers should contact their distributor representative or field application engineer FAE for support Local sales offices are also available to help customers A listing of sales offices and locations is included in the back of this document Technical support is available through the web site at http support microchip com ___ A SOS e M Z amw T adt 2005 Microchip Technology Inc DS33014J page 7 Assembler Linker Librarian User s Guide NOTES DS33014J page 8 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE PICmicro Language Tools and MPLAB IDE INTRODUCTION The MPASM assembler the MPLINK object linker and the MPLIB object librarian are typically used together under MPLAB IDE to provide GUI development of application code for PICmicro MCU dev
321. st or processor directive 224 Use of this instruction is not recommended The instruction is being obsoleted and is not recommended for current use However it is still supported for legacy reasons 225 Invalid label in operand Operand was not a valid address For example if the user tried to issue a CALL to a MACRO name 226 Destination address must be word aligned The destination address is not aligned with the start of a program memory word For this device use even bytes to specify address 227 Substituting RETLW 0 for RETURN pseudo op Using retlw 0 instead of return to resume program execution 228 Invalid ROM location specified The data memory location specified is not valid for the operation specified or is non existant 229 extended mode is not in effect overriden by command line A command line option has disabled extended mode operation 230 CONFIG has been deprecated for PIC18 devices Use directive CONFIG Although you may still use the config directive for PIC18 MCU devices it is strongly recommended that you use the con ig directive no leading underscores instead For PIC18FXXJ MCUS you must user the config directive 2005 Microchip Technology Inc DS33014J page 165 Assembler Linker Librarian User s Guide UNKNOWN WARNING An internal application error has occurred is the value of the last defined warning plus 1 However it is not severe enough to keep your code
322. t 0x14 area set length width length set length 1 4 57 6 Application Example set equ This example shows the usage of the set directive used for creating symbols which may be used in MPASM assembler expressions only The symbols created with this directive do not occupy any physical memory location on the microcontroller include p16f877a inc Include standard header file for the selected device 2005 Microchip Technology Inc DS33014J page 109 Assembler Linker Librarian User s Guide perimeter set 0 The label perimeter is assigned value 0 area set 0 The label area is assigned value 0 The value assigned by the set directive may be reassigned later lngth equ 50H The label lngth is assigned the value 50H wdth equ 25H The label wdth is assigned the value 25H The value assigned by the equ directive may not be reassigned later perimeter set 2 lngth wdth Both perimeter and area set Ingth wdth area values are reassigned end 4 58 space INSERT BLANK LISTING LINES 4 58 1 Syntax Preferred space expr Supported spac expr 4 58 2 Description and Usage Insert expr number of blank lines into the listing file This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation 4 58 3 See Also list 4 58 4 Simple Example space 3 Inserts three blank lines
323. tandard include file include c Program Files mydefs inc user defines 4 42 list LISTING OPTIONS 4 42 41 Syntax list list option list option 4 42 2 Description Occurring on a line by itself the 1ist directive has the effect of turning listing output on if it had been previously turned off Otherwise one of a list of options can be supplied to control the assembly process or format the listing file 4 42 3 Usage This directive is used in the following types of code absolute or relocatable For information on types of code see Section 1 6 Assembler Operation Options that may be used with the 1ist directive are specified below Option Default Description b nnn 8 Set tab spaces c nnn 132 Set column width f format INHX8M Set the hex file output format can be INHX32 INHX8M or INHX8S Note Hex file format is set in MPLAB IDE Build Options dialog free FIXED Use free format parser Provided for backward compatibility fixed FIXED Use fixed format parser mm ON OFF On Print memory map in list file n nnn 60 Set lines per page p type None Set processor type for example PIC16F54 See also processor Note Processor type is set in MPLAB IDE Configure Device pe type None Set processor type and enable extended instruction set for example LIST pe PIC18F4620 Only valid with processors which support the extended instruction set and the generic processor PIC18XX
324. tandby Mode 0 gt WDT stop oscillator oor TRIS r Tristate port r WREG gt I O control reg r Fkk XORLW kk Exclusive OR literal and W kk XOR WREG gt WREG A 4 14 BIT INSTRUCTION WIDTH INSTRUCTION SET Microchip s midrange 8 bit microcontroller family uses a 14 bit wide instruction set This instruction set consists of 36 instructions each a single 14 bit wide word Most instructions operate on a file register f and the working register WREG accumulator The result can be directed either to the file register or the WREG register or to both in the case of some instructions A few instructions operate solely on a file register BSF for example The instruction set is grouped into the following categories byte oriented file register operations bit oriented file register operations and core literal and control operations Additionally instructions that apply to both 12 bit and 14 bit devices are shown in Section A 5 12 Bit 14 Bit Instruction Width Pseudo Instructions Instruction opcode is show in hex by making certain assumptions either listed in the key or as a footnote For more information on the opcode bit values for each instruction as well as the number of cycles per instruction Status bits affected and complete instruction details see the relevant device data sheet TABLE A 4 14 BIT BYTE ORIENTED FILE REGISTER OPERATIONS Hex Mnemonic Description Function 07df ADDWF
325. tarts at address 0x04 and has a length of 0x018 13 3 3 Finding the Error In the source code template find the code section named INT VECTOR INT VECTOR CODE 0x004 interrupt vector location This code statement defines an absolute start address at location 0x04 which is the interrupt vector on the PIC16F877A The source code the INT VECTOR section continues until the next CODE statement Counting the number of instructions you should see that the length of the INT VECTOR section is indeed 0x018 bytes This confirms that this is the code causing the linker error In the linker script template find the region named vectors CODEPAGE NAME vectors START 0x0000 END 0x0004 PROTECTED In this statement a section has been defined with a start address of 0x0 and an end address of 0x04 This section has been defined with these addresses in order to give the PROTECTED attribute to both the reset vector location 0x0 and to the reset location 0x04 i e the linker will not automatically place code in the reset section As you can now see the code section INT VECTOR cannot fit into linker region vectors and this is causing the error TABLE 13 1 PROGRAM MEMORY MAP PIC16F877A Program Memory Linker Script Section Source Code Section Address 0x0000 RESET VECTOR Reset vector 0x0003 vectors Reset interrupt vectors 0x0004 0x0005 INT VECTOR Interrupt vector 0x001C page0 ROM code space page 0
326. tension from assembler for cross reference files Symbol and Debug File cod Output extension for the symbol and debug file For absolute code this file will be generated by the assembler For relocatable code this file and a coff file will be generated by the MPLINK linker See MPLINK linker documentation for more details Object File 0 Output extension from assembler for object files 1 7 1 Source Code asm Assembly is a programming language you may use to develop the source code for your application The source code file may be created using any ASCII text file editor Note Several example source code files are included free with MPLAB IDE Your source code should conform to the following basic guidelines Each line of the source file may contain up to four types of information Labels Mnemonics Directives and Macros Operands Comments The order and position of these are important For ease of debugging it is recommended that labels start in column one and mnemonics start in column two or beyond Operands follow the mnemonic Comments may follow the operands mnemonics or labels and can start in any column The maximum column width is 255 characters White space or a colon must separate the label and the mnemonic and white space must separate the mnemonic and the operand s Multiple operands must be separated by commas White space is one or more spaces or tabs White space is u
327. the beginning of your code Use the configuration options names in the standard include inc file These names can be bitwise ANDed together using amp to declare multiple configuration bits 4 11 4 See Also config _ idlocs list processor DS33014J page 58 2005 Microchip Technology Inc Directives 4 11 5 Simple Examples Example 1 PIC16 Devices include p16f877a inc include file with config bit definitions _ config HS OSC amp WDT OFF amp LVP OFF Set oscillator to HS watchdog time off low voltage prog off Example 2 PIC17X Devices include p17c42 inc include file with config bit definitions _ config OxFFFF default configuration bits Example 3 PIC18 Devices include p18c452 inc Include standard header file for the selected device code protect disabled CONFIG _CONFIGO CP OFF O0 Oscillator switch disabled RC oscillator with OSC2 as I O pin CONFIG _CONFIG1 OSCS OFF 1 amp RCIO OSC 1 Brown OutReset enabled BOR Voltage is 2 5v __ CONFIG _CONFIG2 BOR ON 2 amp BORV 25 2 Watch Dog Timer enable Watch Dog Timer PostScaler count 1 128 CONFIG _CONFIG3 WDT ON 3 amp WDTPS 128 3 CCP2 pin Mux enabled _ CONFIG _CONFIG5 _CCP2MX ON 5 Stack over underflow Reset enabled CONFIG _CONFIG6 _STVR ON 6 4 12 config SET PROCESSOR CONFIGURATION BITS PIC18 MCUs 4 12 4 Syntax config setting value setting value 4 12 2 Description Defines a
328. the radix However if you need to change the radix in your program you should exercise care as all numeric values following the radix declaration will use that radix value See the radix example for more on the implications of changing the radix Use the radix directive or the 1ist directive option x to change the radix in your code 4 55 4 See Also list 4 55 5 Simple Example radix dec DS33014J page 106 2005 Microchip Technology Inc Directives 4 55 6 Application Example radix This example shows the usage of the radix directive for data presentation If not declared then the default radix is in hex adecimal list r dec Set the radix as decimal include p16f877a inc Include standard header file for the selected device movlw 50H 50 is in hex movlw 0x50 Another way of declaring 50 hex movlw 500 50 is in octal moviw 50 50 is not declared as hex or octal or decimal So by default it is in decimal as default radix is declared as decimal radix oct Use radix to declare default radix as octal movlw 50H 50 is in hex movlw 0x50 Another way of declaring 50 hex movlw 50 50 is in decimal moviw 50 50 is not declared as hex or octal or decimal So by default it is in octal as default radix is declared as octal radix hex Now default radix is in hex movlw 50 50 is declared in decimal movlw 500 50 is declared in octal moviw 50 50 is not declared as hex or oct
329. this chapter MPLINK Linker Defined How MPLINK Linker Works How MPLINK Linker Helps You Linker Platforms Supported Linker Operation Linker Input Output Files 9 2 MPLINK LINKER DEFINED MPLINK object linker the linker combines object modules generated by the MPASM assembler or the MPLAB C18 C compiler into a single executable hex file The linker also accepts libraries of object files as input as generated by the MPLIB object librarian The linking process is controlled by a linker script file which is also input into MPLINK linker For more information on MPASM assembler see Chapter 1 MPASM Assembler Overview For more information on MPLAB C18 see C compiler documentation listed in Recommended Reading 9 3 HOW MPLINK LINKER WORKS MPLINK linker performs many functions Locates Code and Data The linker takes as input relocatable object files Using the linker script it decides where the code will be placed in program memory and where variables will be placed in RAM Resolves Addresses External references in a source file generate relocation entries in the object file After the linker locates code and data it uses this relocation information to update all external references with the actual addresses Generates an Executable Produces a hex file that can be programmed into a PICmicro MCU or loaded into an emulator or simulator to be executed Configures Stack Size and Location Allows MPLAB C18 to set aside RA
330. this example are Program Functional Description Commented Code Listing Header Files Register and Bit Assignments Program Memory CODE Sections and Paging Banking Interrupts 5 3 1 Program Functional Description This program continually alternates the output on the PORTB pins from 1 s to 0 s Two delay routines using interrupts provide the timing for the alternating output If LEDs were attached to PORTB they would flash 1 on 0 off The type of PlCmicro MCU is set in MPLAB IDE so does not need to be set in code However if you wish to specify the MCU as well as radix in code you may do so using the processor and radix directives or list command i e list p 16f877a r hex The application is written as relocatable code i e you must use both the assembler and linker to generate the executable See PICmicro Language Tools and MPLAB IDE for information on how to set up a project using assembler files and a linker script The standard header file for the processor selected is included using include Registers are assigned using the udata res and equ directives Sections of code are created using the code statement Data memory banking and program memory paging is accomplished as needed using banksel and pagesel directives Finally the program is finished with an end 5 3 2 Commented Code Listing PRR RRR RRR RRR e kkk kkk kkk k he ke e k ke ke k he ke e ke ke ke e k MPASM Assembler Control Directives
331. thod is very useful for creating reusable modules 0000000 main hex PN main asm MPASMTM assembler o o o o o o o o o AUX o o o o o o o o 00000000 more asm more o Related modules can be grouped and stored together in a library using Microchip s MPLIB librarian Required libraries can be specified at link time and only the routines that are needed will be included in the final executable MPASMTM MPLIBTM unit1 asm assembler librarian PN unit2 asm MPASM MPLIB units lib assembler librarian IS unit3 asm MPASM MPLIB assembler librarian unit3 0 Refer to Chapter 6 Relocatable Objects for more information on the differences between absolute and relocatable object assembly 2005 Microchip Technology Inc DS33014J page 23 Assembler Linker Librarian User s Guide 1 7 ASSEMBLER INPUT OUTPUT FILES These are the default file extensions used by the assembler and the associated utility functions TABLE 1 1 INPUT FILES Source Code asm Default source file extension input to assembler Include File inc Include header file TABLE 1 2 OUTPUT FILES Listing File Ist Default output extension for listing files generated by assembler Error File err Output extension from assembler for error files Hex File Formats hex hxl hxh Output extension from assembler for hex files Cross Reference File xrf Output ex
332. tions listed here are grouped either by instruction width or device number Se Devices Supported 12 Bit PIC10F2XX PIC12C5XX PIC12CE5XX PIC16X5X PIC16C505 14 Bit PIC12C67X PIC12CE67X PIC12F629 675 PIC16X 16 Bit PIC18X Topics covered are Key to 12 14 Bit Instruction Width Instruction Sets 12 Bit Instruction Width Instruction Set 14 Bit Instruction Width Instruction Set 12 Bit 14 Bit Instruction Width Pseudo Instructions Key to PIC18 Device Instruction Set PIC18 Device Instruction Set PIC18 Device Extended Instruction Set A 2 KEY TO 12 14 BIT INSTRUCTION WIDTH INSTRUCTION SETS Field Description Register Files dest Destination either the WREG register or the specified register file location See Register file address 5 bit 7 bit or 8 bit p Peripheral register file address 5 bit r Port for TRIS x Don t care 0 or 1 The assembler will generate code with x 0 It is the recommended form of use for compatibility with all Microchip software tools Literals k Literal field constant data or label k 4 bit kk 8 bit kkk 12 bit 2005 Microchip Technology Inc DS33014J page 237 Assembler Linker Librarian User s Guide Field Description Bits b Bit address within an 8 bit file register 0 to 7 d D
333. tions to define register locations and initialize idata HistoryVector db 0 Initialized to 0 udata InputGain res 1 Control loop gains OutputGain res 1 udata_ovr Templ res 1 Used for internal calculations Temp2 res 1 Temp3 res 1 nc 2005 Microchip Technology Inc DS33014J page 147 Assembler Linker Librarian User s Guide If necessary the location of the section may be fixed in memory by supplying the optional address parameter If more than one of each section type is specified each section must have a unique name If a name is not provided the default section names are idata udata udata acs udata shr and udata ovr When defining initialized data in an idata section the directives db dw and data can be used db will define successive bytes of data memory dw and data will define successive words of data memory in low byte high byte order The following example shows how data will be initialized EXAMPLE 6 5 RELOCATABLE CODE LISTING 00001 IDATA 0000 01 02 03 00002 Bytes DB 1 2 3 0003 34 12 78 56 00003 Words DW 0x1234 0x5678 0007 41 42 43 00 00004 String DB ABC O 6 6 CONFIGURATION BITS AND ID LOCATIONS Configuration bits and ID locations can still be defined in a relocatable object using the following directives e Section 4 11 con ig Set Processor Configuration Bits Section 4 12 config Set Processor Configuration Bits PIC18 MCUs e Section 4 37 idlocs Set Processor ID Loc
334. tive must be supplied to terminate the CBLOCK list clrf perimeter 1 Clear perimeter high byte at address 21H movf length w Move the data present in the register addressed by length tO hw addwf width w Add data in w with data in the register addressed by width STATUS register carry bit C may be affected movwf perimeter Move w to the perimeter low byte at address 20H Carry bit is unaffected rlf perimeter 1 Increment register 21H if carry was generated Also clear carry if bit was set rlf perimeter Multiply register 20H by 2 Carry bit may be affected rlf perimeter 1 Again increment register 21H if carry was generated goto Go to current line loop here end Sa c C Se U m RM 2005 Microchip Technology Inc DS33014J page 55 Assembler Linker Librarian User s Guide 4 9 code BEGIN AN OBJECT FILE CODE SECTION 4 9 1 Syntax 1abel code ROM address 4 9 2 Description This directive declares the beginning of a section of program code If label is not specified the section is named code The starting address is initialized to the specified address or will be assigned at link time if no address is specified Note Two sections in a source file may not have the same name 4 9 3 Usage This directive is used in the following types of code relocatabl
335. type System A term referring to a user s target application or target board PWM Signals Pulse Width Modulation Signals Certain PICmicro MCU devices have a PWM peripheral Qualifier An address or an address range used by the Pass Counter or as an event before another operation in a complex trigger Radix The number base hex or decimal used in specifying an address 2005 Microchip Technology Inc DS33014J page 259 Assembler Linker Librarian User s Guide RAM Random Access Memory Data Memory Memory in which information can be accessed in any order Raw Data The binary representation of code or data associated with a section Real Time When released from the halt state in the emulator or MPLAB ICD mode the processor runs in real time mode and behaves exactly as the normal chip would behave In real time mode the real time trace buffer of MPLAB ICE is enabled and constantly cap tures all selected cycles and all break logic is enabled In the emulator or MPLAB ICD the processor executes in real time until a valid breakpoint causes a halt or until the user halts the emulator In the simulator real time simply means execution of the microcontroller instructions as fast as they can be simulated by the host CPU Recursion The concept that a function or macro having been defined can call itself Great care should be taken when writing recursive macros it is easy to get caught in an infinite loop where there
336. types of code see Section 1 6 Assembler Operation This directive may be used with 14 bit instruction width PICmicro devices This excludes 12 bit instruction width devices and PIC18 devices 4 6 4 See Also banksel pagesel 4 6 5 Simple Example movlw Varl movwf FSR Load the address of Varli info FSR bankisel Varl Select the correct bank for Varl movwf INDF Indirectly write to Varl DS33014J page 50 2005 Microchip Technology Inc Directives 4 6 6 Application Example bankisel This program demonstrates the bankisel directive This directive generates the appropriate code to set clear the IRP bit of the STATUS register for an indirect access include p16f877a inc groupl udata 0x20 groupl varl res 1 groupl var2 res 1 group2 udata 0x120 group2 varl res 1 group2 var2 res 1 RST CODE 0x0 pagesel start goto start PGM CODE start movlw 0x20 movwf FSR bankisel groupl varl clrf INDF incf FSR F clrf INDF movwf FSR bankisel group2 varl clrf INDF incf FSR F clrf INDF goto end Include stan for the sele groupl data Starting at groupl vari groupl var2 group2 data starting at group2 varl group2 var2 The code sec is placed at location 0x0 instructions code section Jumps to the start dard header file cted device stored at locations 0x20 IRP bit 0 located at 0x20 located at 0x21 stored at locations 0x120 IRP bit 1 located at 0x120
337. uced Section secName contains code and can not have a RAM memory attribute specified in the linker command file Use only the ROM attribute when defining the section in the linker command file Section secName contains initialized data and can not have a ROM memory attribute specified in the linker command file Use only the RAM attribute when defining the section in the linker command file Section secName contains initialized rom data and can not have a RAM memory attribute specified in the linker command file Use only the ROM attribute when defining the section in the linker command file 2005 Microchip Technology Inc DS33014J page 217 Assembler Linker Librarian User s Guide Section secName contains uninitialized data and can not have a ROM memory attribute specified in the linker command file Use only the RAM attribute when defining the section in the linker command file Section secName has a memory nemName which can not fit the absolute section Section secName start 0xHHHH length 0xHHHH The memory which was assigned to the section in the linker command file either does not have space to fit the section or the section will overlap another section Use the m lt mapfile gt switch to generate an error map file The error map will show the sections which were allocated prior to the error Section secName has a memory memName which can not fit the section Section secName length 0
338. ult 40960 768 128 15 41871 Decimal DS33014J page 250 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Glossary Absolute Section A section with a fixed absolute address that cannot be changed by the linker Access Memory PIC18 Only Special registers on PIC18 devices that allow access regardless of the setting of the Bank Select Register BSR Address Value that identifies a location in memory Alphabetic Character Alphabetic characters are those characters that are letters of the arabic alphabet a b Z A B Z Alphanumeric Alphanumeric characters are comprised of alphabetic characters and decimal digits 0 1 9 ANSI American National Standards Institute is an organization responsible for formulating and approving standards in the United States Application A set of software and hardware that may be controlled by a PICmicro microcontroller Archive A collection of relocatable object modules It is created by assembling multiple source files to object files and then using the archiver to combine the object files into one library file A library can be linked with object modules and other libraries to create executable code Archiver A tool that creates and manipulates libraries ASCII American Standard Code for Information Interchange is a character set encoding that uses 7 binary digits to represent each character It includes upper and lowe
339. umber file line description For example Error 113 C PROG ASM 7 Symbol not previously defined start The error file may contain any number of MPASM assembler errors warnings and messages For more on these see Chapter 8 Errors Warnings Messages and Limitations To prevent error file generation use the e option 1 7 5 Hex File Formats hex hxl hxh The MPASM assembler and MPLINK linker are capable of producing ASCII text hex files in different formats Format Name Format Type File Extension Use Intel Hex Format INHX8M hex 8 bit core device programmers Intel Split Hex Format INHX8S hxl hxh odd even programmers Intel Hex 32 Format INHX32 hex 16 bit core device programmers This file format is useful for transferring PlCmicro MCU series code to Microchip programmers and third party PICmicro MCU programmers 1 7 5 1 INTEL HEX FORMAT This format produces one 8 bit hex file with a low byte high byte combination Since each address can only contain 8 bits in this format all addresses are doubled Each data record begins with a 9 character prefix and ends with a 2 character checksum Each record has the following format BBAAAATTHHHH HHHCC where BB A two digit hexadecimal byte count representing the number of data bytes that will appear on the line AAAA A four digit hexadecimal address representing the starting address of the data record TT A two digit record type th
340. ust be of equal length Internal Coff output file is corrupt The linker cannot write to the COFF file Memory memName overlaps memory memName All CODEPAGE blocks must specify unique memory ranges which do not overlap Similarly DATABANK and SHAREBANK blocks may not overlap Mixing extended and non extended mode modules not allowed The linker cannot link a mixture of extended mode modules and non extended mode modules Extended and non extended memory modes apply to PIC18 devices When using MPASM to create object file modules extended memory mode is enabled disabled on the command line using the y option In MPLAB IDE select Project gt Build Options MPASM Assembly tab and check uncheck the option Extended Mode When using MPLAB C18 to create object file modules extended memory mode is enabled disabled on the command line using the extended option In MPLAB IDE select Project gt Build Options MPLAB C18 tab and check uncheck the option Extended Mode When using linker scripts those with the suffix e apply to extended mode use MPASM s _ CONFIG directive found in bar o cannot be used with either MPLAB C18 s pragma config directive or MPASM s CONFIG directive found in foo o This error message is issued when MPASM assemblers CONFIG directive is specified in a asm file e g bar asm and MPLAB C18 s pragma config directive is specified in a c file e g oo c Set configuration bits usin
341. utput files see the MPLINK linker documentation For more on projects and related workspaces see MPLAB IDE documentation DS33014J page 12 O 2005 Microchip Technology Inc PlCmicro Language Tools and MPLAB IDE PROJECT SETUP To set up an MPLAB IDE project for the first time it is advisable to use the built in Project Wizard Project Project Wizard In this wizard you will be able to select a language toolsuite that uses MPASM assembler e g the Microchip MPASM Toolsuite For more on the wizard and MPLAB IDE projects see MPLAB IDE documentation Once you have a project set up you may then set up properties of the tools in MPLAB IDE 1 From the MPLAB IDE menu bar select Project Build Options gt Projectto open a dialog to set check project build options Note MPASM assembler does not recognize include path information specified in MPLAB IDE 2 Click on the Tool tab to modify tool settings Build Options Dialog MPASM Assembler tab Build Options Dialog MPLINK Linker tab Build Options Dialog MPASM C17 C18 Suite tab Build Options Dialog MPASM Assembler Tab Select a category and then set up assembler options For additional options see Chapter 2 Assembler Interfaces General Category Generate Command Line Disable case sensitivity The assembler will not distinguish between uppercase and lowercase letters Note Disabling case sensitivity will make all labels uppercase Extended m
342. w 101 ERROR User error invoked with the error directive 102 Out of memory Not enough memory for macros define s or internal processing 103 Symbol table full No more memory available for the symbol table 104 Temp file creation error Could not create a temporary file Check the available disk space 105 Cannot open file Could not open a file If it is a source file the file may not exist If it is an output file the old version may be write protected To check for write protect right click on the file named by MPLAB IDE in Windows Choose Properties and see if read only is checked If it is it cannot be modified by MPLAB IDE and will generate this error message This often happens when you save your project to a CD R or similar write once media as a backup and then copy the data to your computer Copying to a CD marks all files as read only they cannot be changed on a CD R and when you copy the files the attributes move with them making them 2005 Microchip Technology Inc DS33014J page 157 Assembler Linker Librarian User s Guide all read only on your hard drive A good way to prevent this is to archive all of the files in one file such as a ZIP and then restore them from CD The archive will preserve the original file attributes 106 String substitution too complex A string substitution was attempted that was too complex Check for nesting of define s 107 Illegal digit An
343. w the project output files by opening the files in MPLAB IDE 1 Select File gt Open In the Open dialog find the project directory 2 Under Files of type select All files to see all project files 3 Select Example xrf Click Open to view the assembler cross reference file for Example asm in an MPLAB IDE editor window For more on this file see Section 1 7 6 Cross Reference File xrf 4 Repeat steps 1 and 2 Select Example map Click Open to view the linker map file in an MPLAB IDE editor window For more on this file see Section 9 7 8 Map File map 5 Repeat steps 1 and 2 Select Example Ist Click Open to view the linker listing file in an MPLAB IDE editor window When MPASM assembler is used with MPLINK linker the listing file is generated by the linker For more on this file see Section 9 7 7 Listing File Ist 6 Repeat steps 1 and 2 Notice that there is only one hex file Example hex This is the primary output file used by various debug tools You do not view this file for debugging use instead View Program Memory or View gt Disassembly Listing DS33014J page 16 O 2005 Microchip Technology Inc PlCmicro Language Tools and MPLAB IDE Further Development Usually your application code will not build without errors Therefore you will need a debug tool to help you develop your code Using the output files previously discussed several debug tools exist that work with MPL
344. where allocSizeis the size in bytes of the stack and memName is the name of a memory previously declared using a ACCESSBANK DATABANK Or SHAREBANK statement EXAMPLE 11 9 STACK EXAMPLE To set the stack size to be 0x20 in the RAM area previously defined by gpro the following line should be added to the linker command file STACK SIZE 0x20 RAM gprO0 DS33014J page 186 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 12 Linker Processing INTRODUCTION Understanding how MPLINK linker processes files and information can be useful to keep in mind when writing and structuring your application code Topics covered in this chapter Linker Processing Overview Linker Allocation Algorithm Relocation Example Initialized Data Reserved Section Names 12 2 LINKER PROCESSING OVERVIEW A linker combines multiple input object modules into a single executable output module The input object modules may contain relocatable or absolute sections of code or data which the linker will allocate into target memory The target memory architecture is described in a linker command file This linker command file provides a flexible mechanism for specifying blocks of target memory and for mapping sections to the specified memory blocks If the linker cannot find a block of target memory in which to allocate a section an error is generated The linker combines like named input sections into a
345. word location in external SRAM memory movwf upper SRAM BASE ADDRS movwf TBLPTRU movlw high SRAM BASE ADDRS movwf TBLPTRH movlw low SRAM BASE ADDRS movwf TBLPTRL movlw OxCC movwf TBLLAT thlwt Writes OxCC to byte location 0x020000 Increments table pointer to next location movlw 0x55 movwf TBLLAT tblwt Write 0x55 to byte location 0x020001 13 6 10 Building the MPASM Assembler Application To build the MPASM assembler sample application refer to Section 13 2 How to Build the Sample Applications The linker script file for this sample application is a modification of the standard linker file for the device DS33014J page 212 2005 Microchip Technology Inc ASSEMBLER LINKER LIBRARIAN MICROCHIP USER S GUIDE Chapter 14 Errors Warnings and Common Problems 14 1 INTRODUCTION Error messages and warning messages are produced by the MPLINK linker These messages always appear in the listing file directly above each line in which the error occurred Common problems and limitations of the linker tool are also listed here Topics covered in this chapter Linker Parse Errors Linker Errors Linker Warnings Library File Errors COFF File Errors COFF To COD Conversion Errors COFF To COD Converter Warnings Common Problems 14 2 LINKER PARSE ERRORS MPLINK linker parse errors are listed alphabetically below Could not open cmdfile A linker command file could not be opene
346. xHHHH The memory which was assigned to the section in the linker command file either does not have space to fit the section or the section will overlap another section Use the m mapfile switch to generate an error map file The error map will show the sections which were allocated prior to the error Section secName has a memory memName which is not defined in the linker command file Add a CODEPAGE DATABANK or SHAREBANK directive for the undefined memory to the linker command file Section secName type is non overlay and absolute but occurs in more than one input file An absolute section with the name secName may only occur in a single input file Relocatable sections with the same name may occur in multiple input files Either remove the multiple absolute sections in the source files or use relocatable sections instead Starting addresses for absolute overlay section secName do not match accross all input files A section with the name secName occurs in more than one input file However its absolute overlay starting address varies between files Change the section s address in the source files and rebuild the object modules Symbol symName has multiple definitions A symbol may only be defined in a single input module Symbol symName is not word aligned It cannot be used as the target of a branch call or goto instruction The target of a branch call or goto instruction was at an odd address but t
347. xample test_mac macro count variable i 4 0 while i count movlw i i 1 endw endm start test mac 5 end 4 67 6 Application Example while endw This example shows the usefulness of directive while to perform a loop while a certain condition is true This directive is used with the endw directive include p16f877a inc Include standard header file for the selected device variable i Define the symbol i as a variable mydata udata 0x20 Allocate RAM for labels reg hi res 1 reg hi and reg 1o reg lo res 1 RST CODE 0x0 The code section named RST is placed at program memory location 0x0 The next two instructions are placed in code section RST pagesel start Jumps to the location labelled goto start DUSstart shift right macro by n Beginning of a macro which shifts register data n times Code length generated after assembly varies depending upon the value of parameter by n 1 0 Initialize variable i while i lt by n Following 3 lines of assembly code are repeated as long as DS33014J page 120 2005 Microchip Technology Inc Directives i by n Up to 100 lines of codes are allowed inside a while loop bcf STATUS C Clear carry bit rrf reg hi F reg hi and reg lo contains rrf reg lo F 16 bit data which is rotated right through carry i 1 Increment loop counter i i cannot increment to more than 255 decimal endw End while loop The loop will
348. xamples are demonstrated using a PIC18F8722 which offers a configurable boot block size of 2K 4K or 8K bytes The remaining program memory is available for the relocatable application code and data tables For these two examples it is assumed the boot block is configured for 2 Kbytes and requires modification to the MPLAB C168 linker script file in order to accommodate the selected boot block size The third example a mix of an MPASM boot loader and MPLAB C18 source code uses the PIC18F8720 For the corresponding memory map see Section 13 6 7 MPASM Assembler Memory Map RT MB AA sc gs A DS33014J page 198 2005 Microchip Technology Inc Sample Applications TABLE 13 3 PROGRAM MEMORY MAP PIC18F8722 Program Memory Linker Script Section Source Code Section Address 0x000000 0x000029 vectors Reset Interrupts Vectors IntH IntL 0x00002A 0x0007FF boot Boot Loader Boot 0x000800 0x000829 rm vectors Remapped Vectors R vectors R_IntH R_IntL 0x00082A u er code serCode user_code Boot Loader Updated 0x1FFFFF zi Application Code 13 5 3 MPLAB C18 Boot Loader Linker Script The partial MPLAB C18 linker script file shown below demonstrates the modifications requir
349. ying radix see Section 3 4 Numeric Constants and Radix You are encouraged to develop using the radix and other directive methods described within this document even though certain older syntaxes may be supported for compatibility reasons 1 6 ASSEMBLER OPERATION The MPASM assembler can be used in two ways To generate absolute code that can be executed directly by a microcontroller To generate relocatable code that can be linked with other separately assembled or compiled modules 1 6 1 Generating Absolute Code Absolute code is the default output from the MPASM assembler This process is shown below code asm MPASMTM code hex Programmer assembler gramme When a source file is assembled in this manner all variables and routines used in the source file must be defined within that source file or in files that have been explicitly included by that source file If assembly proceeds without errors a hex file will be generated containing the executable machine code for the target device This file can then be used with a debugger to test code execution or with a device programmer to program the microcontroller DS33014J page 22 2005 Microchip Technology Inc MPASM Assembler Overview 1 6 2 Generating Relocatable Code The MPASM assembler also has the ability to generate a relocatable object module that can be linked with other modules using Microchip s MPLINK linker to form the final executable code This me

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