Using Your NanoCore12 Microcontroller Module
Contents
1. All of the subsystems are identical with the differentiating factor among the chips being the amounts of Flash and RAM included on the chip NanoCore modules are completely self contained including RS232 interface and 5V regulator circuitry right on the module You can simply plug it into any solderless breadboard to use it For added convenience though a Docking Module is offered which provides addi tional support for working with the microcontroller It includes a bigger voltage regulator which has extra available current to spare for your applications The voltage regulator also has a jumper option for 3 Volt operation Other features include a standard 9 pin D sub connector for the RS232 serial interface a socket for the MCU module a couple of user LEDs and pushbuttons and a snap off prototyping area A similar product the School Board has a section of solderless breadboard instead of the snap off prototyping area This configuration is ideal for quick experimentation and training purposes Product bundles are offered for both and include a power supply a serial cable and a resource CD containing this manual example programs software tools and a collection of MCU docu mentation from Freescale An optional CD containing the free 32K Special Edition of Metrowerk s CodeWarrior C compiler is available upon request NanoCorei2 modules are offered in 24 pin 32 pin and 40 pin DIP footprints that plug into the DIP socket on the Docking2. RS232C Interface BDM Connector 8 MHz Crystal VING vssG RESO vcc PT7 PT6 9S12C MCU PT5 PIA PT3 PT20 PTI PTOG o 9 o o o o e o Ei 60000006 0 Ga om o 4 oe o bk o HM 0 6 fe o 6 pin BDM Connector N 2 ECLK Pad Load Run Switch PINOUT TOP VIEW BOTTOM VIEW END VIEW top view NanoCore12DX MCU Module ECLK pad Voltage Regulator RS232C Interface 1 e BDM Connector 2 e e 8 MHz Crystal e 4 e 5 o 6 9S12C MCU Ze d o 8 e e 9 0 6 fe i e o 12 6 pin BDM Connector o 13 14 Boot Run Switch 15 PM3 16 PM2 TOP VIEW BOTTOM VIEW END VIEW PINOUT top view NanoCorei2MAX MCU Module ECLK Pin RS232C Interface PE4 Voltage Regulator BDM Connector 8 MHz Crystal mar lt if 9S12C MCU mo o N OA bk o HM a jon CAN Interface gt 0 6 fe y 6 pin BDM Connector Goeoooeooeeoeeoeooeeeoo o o o o o O O o o o o o o o o o o o o Load Run Switch TOP VIEW BOTTOM VIEW END VIEW PINOUT top view
3. Module or the socket strips on a School Board While the standard configuration incorporates the 9512C32 MCU a 9512C128 version is also available on the 40 pin MAX offering four times the program space 128K vs 32K and double the RAM 4K vs 2K 1 4 NC12 VS TRADITIONAL EVALUATION BOARDS Most available evaluation and development systems tend to be too expensive and bulky for embedding into a real application so they lie on a shelf gathering dust once you ve reached a certain point in the learning curve Or maybe you think up some clever way to hack it apart and make it fit inside your robot or product prototype Even then the prototyping area provided is often limited and does not lend itself to re usability And what if you burn out a chip the night before the contest or product demo What a mess to repair or re design NanoCore12 solves all of these problems and more Since the MCU modules are packaged in standard DIP footprints they are modular and re usable They can simply be plugged into your application or moved from one application board to another allowing your whole system to be re configured at the last minute The prototyping area on the Docking Module offers you a platform for your initial application which can be snapped off and discarded when you no longer need it Two 40 pin connector footprints remain and can be used with various types of connectors ribbon cables backplanes prototyping cards etc that are availa
4. page of this manual to determine the correct connections Your DC supply does not need to be regulated but it should be capable of supplying at least 100 mA more if you will be using a BDM pod or you re driving other circuits as well If your supply will also be driving motors make sure to isolate it before feeding it into the module to protect it from electrical noise generated by the motor coils You can do this by putting inductors 10uH nominal in series with both the and leads Preferably use the red amp black power wire provided order code PCJ1 8 Red is positive and black is negative ground CAUTION Make sure you have the polarity correct Option 2 supply regulated 5VDC or 3VDC if using 3 Volt mode via the Vcc 3V pin and Vss Ground pin on the module See module pinout diagram in Appendix C for the Vcc and GROUND pins to use CAUTION Double check your connections before applying power If you are applying 3V be sure to read the notes on 3 Volt operation in chapter 3 2 2 DEMO PROGRAMS We ve included a few demo programs on the CD ROM also available from the product webpage to give you a starting point There are some examples in C and some in assembler The source code is included so you re free to modify them all you want 2 3 USING THE DEBUG MONITOR uBugl12 is a Windows based graphical user interface GUI for Freescale s HCS12 Serial Monitor program It aims to emulate the most common debug monitor com
5. such claim alleges that the manufacturer was negligent regarding the design or implementation of the product Product features availability and prices may change without notice All trademarks used in this document are the property of their respective holders ESD WARNING This product like all microcontroller products uses semiconductors that can be damaged by electrostatic discharge ESD When handling care must be taken so that the devices are not damaged Damage due to inappropriate handling is not covered by the warranty The following precautions must be taken e Do not open the protective conductive packaging until you have read the following and are at an approved anti static work station e Use a conductive wrist strap attached to a good earth ground e If working on a prototyping board use a soldering iron or station that is marked as ESD safe Always disconnect the microcontroller from the prototyping board when it is being worked on e Always discharge yourself by touching a grounded bare metal surface or approved anti static mat before picking up an ESD sensitive electronic component e Use an approved anti static mat to cover your work surface 1 1 WELCOME With NanoCore12 you are now ready to explore the power and versatility of Freescale s advanced 16 bit microcontroller family Whether you re new to Freescale microcontrollers or you ve used some of the earlier ones such as 68HCO5 68HC11 or 68HC12
6. the monitor program will render the monitor nonfunctional If the PLL loses lock during operation the monitor will fail BLOCK PROTECTION In order to prevent accidental changes to the monitor program itself the 2 Kbyte block of FLASH memory where it resides F800 FFFF is block protected Additionally all write commands are restricted from modifying the monitor memory space The only way to change the contents of this protected block is to use a BDM based development In the lowest cost applications where the monitor is used with an SCI serial interface to the RS232 serial port on a personal computer there is no way to accidentally erase or modify the monitor software COP CONFIGURATION The monitor as written creates hard reset function by using the COP watchdog timer It does so by enabling the COP and waiting for a COP timeout reset to occur If the user application uses the COP two issues must be considered elf the COP is disabled in the user application the monitor will be unable to perform a hard reset and will soft reset to the start of the monitor instead eThe monitor does not service the COP timer If the user application implements COP timer servicing upon re entry into the monitor a hard reset is likely to occur MEMORY CONFIGURATION 1 Register space is 0000 03FF 2 Flash memory is any address greater than 4000 All paged addresses are assumed to be Flash memory 3 RAM ends at 3FFF and builds down to the limit
7. turn to use it 1 5 RESIDENT DEBUG MONITOR Residing in a 2K pro tected block of on chip flash memory is Freescale s versatile CR 7 ERC 7 PETI Serial Monitor program When T a3 7 ED EG Wer e used with uBug12 a free Windows application created by Technological Arts you can display and edit memory and registers erase and program flash set breakpoints and do instruction tracing Flip a switch on NanoCore to Run mode and your program runs automatically from Flash 2000 2317 B3E6 4382 sing E7OB Ace4 OBE Ce a following reset or powerup Ma ep a a E See Chapter 2 and Appendix A aooe 2000 oana 2104 1000 for details on uBug12 and the resident monitor p ETE AA Manic Actes HoEnor COM 2 Dee eRe E S SE 1 6 COMMUNICATIONS An RS 232C serial interface port connector RX amp TX only is included on both the Docking Module and School Board allowing communication with a PC com port or any other device which has an RS 232 serial port via a standard 9 pin serial port extension cable The RS 232 channel is implemented via the SCI of the MCU and when NanoCore is reset in Load mode the resident Serial Monitor uses this port to communicate with an appropriate program running on your PC e g uBug12 In Run mode the RS 232 port is available for your application While the MCU does support Controller Area Network CAN no physical layer circuit is provided on the 24 pin and 32 pin versions of NanoCore12 If
8. you ll be impressed with the well thought out design and implementation of the HCS12 family NanoCorel2 gives you the opportunity to explore the 9S12C family s potential at a very affordable price Add to that the proven advantages of it s popular DIP format and you ll see why you picked a real winner 1 2 SUPPORT To help you get the most out of this product and to make the experience as enjoyable and productive as possible we ve put together a comprehensive website loaded with resources support and applications information If you experience any difficulties or need help with your application the World Wide Web is arguably the most valuable re source available to you There you ll find the latest information software and trouble shooting help as well as discussion groups where you can network with people around the globe to get the answers you need So if you still need help or have questions after reading this manual and perusing the contents of the included CD visit our Support Forum www technologicalarts net and tap into the collective Also be sure to join Freescale s 16 bit Microcontroller discussion group at http forums freescale com freescale board board id 16BITCOMM 1 3 PRODUCT CONFIGURATION NanoCorel 2 was designed as a versatile evaluation and application tool for the Freescale HCS12 C family of microcontrollers It is suitable for developing applications for any of the derivatives e g 9512C32 9512C128
9. you would like to use CAN on either of these modules you ll need to add the appropriate transceiver circuit to PMO and PM1 of the MCU module However the 40 pin module NanoCore12MAX includes an on board CAN transceiver circuit so the CAN interface can be used directly without the need for additional circuitry In passing it should be mentioned that the MCU also supports Serial Peripheral Inter face SPI Since this is a logic level protocol meant for local communications among peripheral chips no transceivers are required nor are they provided Commonly used SPI chips and modules include serial memory e g EEPROM Flash temperature controllers clock calendar chips DACs MP3 decoders etc See the 9S12C datasheets for details on all of these subsystems V reg L 33Vto5V 10 key Wakeup IRQ Ports Be sure to read and follow the Safe Handling Procedures outlined inside the manual s front cover Perform a visual check of the hardware for any damage during transit Connect the Docking Module s or School Board s RS232 port J3 to a com port of a personal computer using the cable supplied Set switch SW2 to the LOAD position Connect the supplied power source to J1 Locate and install the Windows application called uBug12 included on the CD also on our website Launch uBug12 uBug12 will display a short message followed by its command prompt Activate the serial port connection by entering CON x where x is the compor
10. COMMAND LIST a E REGISTERS RD Register Display RM lt RegisterName gt lt Data8 16 gt Register Modify CCR lt Data8 gt Set CCR register D lt Datal6 gt Set D register PC lt Data16 gt Set PC register PP lt Data8 gt Set PP register SP lt Data16 gt Set SP register x lt Datal6 gt Set X register Y lt Datal6 gt Set Y register are a er a tate et te MEMORY MODIFY BF lt StartAdd gt lt EndAdd gt lt Data8 gt Block fill BFW lt StartAdd gt lt EndAdd gt lt Data1i6 gt Block fill word MD lt StartAdd gt lt EndAdd gt Memory display MDW lt StartAdd gt lt EndAdd gt Memory display word MM lt Address gt lt Data8 gt Memory modify byte MMW lt Address gt lt Data16 gt Memory modify word ROPA Len eRe RARA FLASH FBULK Flash bulk erase FLOAD B M Flash load betr E DEVICE INFO DEVICE Get device name a a GO HALT GO lt StartAddress gt Start execution HALT Halt execution RESET Reset target GEELEN GUI ee CON lt Comport gt Connect to target DISCON Disconnect from target EXIT Terminate GUI HELP Display help OP lt Opacity gt Set main GUI opacity 17 APPENDIX C COMPONENT PLACEMENT AND PINOUT NanoCorel 2 MCU Module Voltage Regulator
11. Direction Register there are registers 5 controlling output drive level standard and reduced internal pullup and pulldown resis tors and output logic polarity ie true or inverted logic COP Watchdog On most flavours of HC11 this could be enabled via a bit in the non volatile CONFIG register On the HC12 it is dynamic and automatically enabled following reset Therefore you have to choose whether you re going to service it or disable it Write Once Registers On the HCS12 there is no 64 cycle startup window in which you have to write all the protected registers Instead the HC12 implements a WriteOnce rule on sensitive registers What this means is that following reset you have one chance to write them then they become Read Only The advantage of this is that you have more control of when you alter these register values To take advantage of this safeguard you should initialize all the registers that are crucial even if the default values are what you want That way if your code runs amok or there are any glitches which try to change register values they will be protected There are many more differences and you should make sure to read through the Freescale App Note AN1284 that details the new instructions and addressing modes of the 68HC12 explaining differences from the 68HC11 2 7 MIGRATING FROM THE 68HC912 You gain a lot more speed memory and flexibility but you have a lot more regis ters to think abo
12. Using Your NanoCorel 2 Microcontroller Module www technologicalarts com Revison Oc DISCLAIMER While we have made every effort to avoid errors in the preparation of this manual we cannot be held responsible for any misinformation or omissions that may have occurred Furthermore as manufacturer of this product Technological Arts sole liability and the buyer s exclusive remedy shall be refund of the amount paid or repair or replacement of the product at the manufacturer s option The manufacturer disclaims all other warranties expressed or implied including but not limited to implied warranties of merchantability and fitness for a particular purpose with respect to the product and accompanying written material hardware and firmware In no event shall the manufacturer or its suppliers be held liable for any damages whatsoever including without limitation damages for loss of business profits business interruption loss of business information or any other loss arising out of the use of or inability to use the product even if the manufacturer has been advised of the possibility of such damages The product is not designed intended nor authorized for use in applications in which the failure of the product could bring about a scenario in which personal injury or death may occur If used in any such unintended or unauthorized application the manufacturer and its suppliers shall be held harmless against all claims even if any
13. _start void entry point in crt12 s void main INTR_ON needed for the SerialMonitor 8 DDRT 0x01 Enable LED port use 0x04 for NC12MAX RTICTL Ox7F Set RTI divider for 4Hz time base CRGFLG 0x80 Clear the RTI Flag CRGINT 0x80 Enable the RTI pragma interrupt_handler rti_handler void rti_handlerQ CRGFLG 0x80 Clear the RTI Flag PTT 0x01 Toggle LED use 0x04 for NC12MAX INTR_ON Enable Interrupts pragma abs_address OxFFFO void interrupt_vectors void rti_handler Real Time Interrupt DUMMY_ENTRY IRQ DUMMY_ENTRY XIRQ DUMMY_ENTRY SWI DUMMY_ENTRY Unimplemented Instruction Trap DUMMY_ENTRY COP failure reset DUMMY_ENTRY Clock monitor fail reset _ Start Reset L 4 3 OTHER ISSUES WITH ICC12 Because the register addresses have changed from what they were in HC12 meaning the header file is different for the 9512C32 some library files in ICC12 will need to be re compiled using the new header file if you want to use them Of course if you re not using library functions or you are using functions that don t involve registers then there won t be a problem with the existing versions The modified functions are included on the CD ROM to get you started To use the SCI make sure to include C32_iochar c and C32_serial c Also you ll need the complete vector file for the C32 which is called C32_vectors c Unzip C32_C zip an
14. ance of about 100uF at or close to the J1 connector 3 4 ABOUT THE ON BOARD VOLTAGE REGULATOR NanoCorei2 modules include a tiny LP2981AIM 5 voltage regulator mounted be neath the module It is a low dropout 5V regulator capable of supplying the on board circuitry with the required current with as much as 50 mA to Spare for user applications if the supplied input voltage to the regulator is limited to 6V The higher the input voltage the less current will be available for the user application before thermal shutdown occurs 3 5 PLL While the supplied crystal is only 8MHz the MCU is capable of running at a much higher speed The phase locked loop feature of the MCU allows you to boost the bus speed by an integer multiple of the crystal frequency so by enabling the PLL you can actually run the MCU at 24Mhz 4 1 IMPACT OF THE SERIAL MONTIOR When you are working without a BDM pod the Serial Monitor program is the only method available to load and erase flash It is in a protected block of flash so there s no way to accidentally erase it There are two modes controlled by switch SW2 Run and Load The monitor mode is determined immediately following reset by checking the position of switch SW2 When working with the monitor program in place there are a few points to be noted 1 while the user vectors are implemented by the monitor at OxF780 to OxF7FF you don t really have to worry about it because the monitor program will aut
15. ble now or are under development Make a point to visit our website from time to time just to see what s new There you ll find that various 40 pin connectors are offered for sale if you have trouble locating them from your local electronics store The detachable nature of the prototyping card means that you can easily replace it with other cards including some application cards available from Technological Arts You can build up a collection of different application circuits and use them all with the same microcontroller board Of course if the prototyping card approach doesn t suit you the standard DIP format of NanoCorei2 makes it easy for you to incorporate it into your own designs In fact it s pinout is a superset of the popular 24 pin DIP MCU modules available from other vendors You can plug it into a DIP socket or directly into a solderless bread board If you ve already invested in an application board from another vendor in most cases you can plug a NanoCore12 DIP module in and accomplish some serious applications The modular nature of this product is especially advantageous in an educational environment where the student can progress from simple to more complex applications throughout a semester or from one course to the next even incorporating the board into a final project In fact where budgets are tight different students can share the same microcontroller module and plug in their own interface cards when it s their
16. botics or other mechatronics applications you may be interested in the Servo Sensor Motor Interface board for NanoCore12DX NC12DXSSMI It is similar to the School Board in that it includes a solderless breadboard voltage regulator and serial port connector However it also includes connectors for up to six hobby style R C servos two Devantech sonar distance measuring sensors SRF04 and up to four analog sensors e g Sharp IR distance measuring sensor GP2D120 But perhaps the highlight of the board is the set of two high current H bridges TLE5206 for driving two DC motors up to 4 Amps and 24V The H bridge drivers are connected to the NanoCorel2 s PWM pins for easy speed control implementation Additional features on the board are a microphone and an audio transducer An op amp circuit adds battery voltage monitoring capability via one of the NanoCore12 s analog input pins New application cards are being developed from time to time Check the subcategory called Application Cards on the NanoCore12 webpage to browse the currently available selection 13 14 APPENDIX A SERIAL MONITOR INTRODUCTION This appendix describes the Freescale 2 Kbyte monitor program for the HC9S12 series MCU This program supports 23 primitive debug commands to allow FLASH EEPROM programming and debug through an RS232 serial interface to a personal computer These include commands to reset the target MCU read or modify memory incl
17. d place hcs12c32 h in c icc include or in your equivalent path Make sure to place C32_Vectors c in the same folder as your project and add it to you project via the add file menu item By the way the same files work for the C128 4 4 HELLO WORLD PROGRAM First of all create a new project from the Project menu Then create a new file and save it as HelloWorld c Add it to the Project by right clicking in the Project Panel and using Add Files to add it to the Files section Next type in the following code define _SCI include lt hcs12c32 h gt pragma nonpaged_function start extern void _start void entry point in crt12 s extern int _textmode int putchar char c if _textmode amp amp c n putchar r while SCOSR1 amp TDRE 0 SCODRL c return C void main INTR_ON need to enable interrupts for the SerialMonitor SCIOBD 26 9600 Baud SCIOCR2 Ox0C enable transmitter and receiver puts Hello World pragma abs_address 0xFFFE void interrupt_vectors void L _start Reset Since puts calls putchar we define it before invoking it in main Main has an implicit Start entry point which is called after the setup by CRT12 0 which is a module that the ICC12 linker links in as the starting point of the program Besides initializing the stack and other system features it initializes memory initialized variables and consta
18. e emitted from the transducer If you 1N4148 press and release the Reset button on the a Docking module LED D2 will flash four times and you ll hear four beep sounds ei from the transducer PTO 1 s S d SE PIN 27 on H1 HEADER 4K7 a LS1 L D 1 11 5 3 A Simple Analog Circuit Connect a CdS light sensitive resistor photocell in the configuration shown Then type the letter R to see the value of ANOO change as you vary the amount of light reaching the photocell The value displayed is a 10 bit representation of the voltage level on the ANOO pin with fullscale being approximately 5V represented by the hexadecimal number 3FF 12 ANOO lt PIN 5 on H1 HEADER R1 10K VCC Q a R1 LIGHT SENSOR If you d like to get started interfacing common electronic devices such as LEDs switches relays etc you may consider pur chasing the optional NanoCore12 School Board NC12SB shown The School Board has socket strips to accomodate all three NanoCore12 module sizes i e 24 pin 32 pin and 40 pin and provides a solderless bread board section a reset button a couple of user LEDs a 5V 3V regulator jumper selectable and 9 pin serial connector 9 V battery snaps are provided with robotics applications in mind Mounting hole locations are standardized so as to line up with most hobby robot bases cur rently on the market If you re into ro
19. e with the Analog to Digital converter subsystem should be scaled accordingly One last point is that some BDM pods eg MicroBDM12SX will not work with 3V targets so you should check the specs of the BDM pod you intend to use A good choice is MicroBDM12LX which works with both 3V and 5V targets 3 2 RESET Unlike previous HC11 and HC12 designs the 9512C MCU has an on chip low voltage inhibit LVI reset circuit so it is not necessary to provide such a circuit externally A momentary tact switch is provided for manual reset and the LVI circuit will provide a clean reset signal upon power up 3 3 ABOUT THE DOCKING MODULE VOLTAGE REGULATOR The NanoCore12 Docking Module also the School Board includes an LM1086CT ADJ voltage regulator Housed in a TO 220 package it is capable of dissipating about 500 mW at room temperature Other nice features are reasonably low quiescent current and low dropout voltage it will work with an input voltage down to about 5 Volts or 3 Volts in 3 Volt Mode making it quite well suited to battery operation It is also designed to withstand reverse polarity One drawback however is that it can become unstable and start to oscillate at low temperatures especially if the input voltage source is connected to Ji via long wires If low temperature operation is anticipated the on board 10uF tantalum capacitor can be replaced with a higher value 47uF or 100uF To compensate for long lead in wires add capacit
20. mands and to provide an easy to use interface The following paragraphs will help you get started with uBug12 One nice feature you ll discover is command line history Use the UP and DOWN arrows on your keyboard to recall previously typed commands You can then edit them as needed before hitting lt ENTER gt 2 4 NEW TO FREESCALE MICROCONTROLLERS If you ve come from an 8051 PIC or other background or have never used micro controllers before you should get up to speed on Freescale MCUs by reading Understand ing Small Microcontrollers found on the CD ROM Written by Freescale s Jim Sibigtroth principal design engineer of the HC12 family this excellent book uses an earlier MCU 68HCOS5 to introduce you to the basic concepts and design philosophy upon which the 9512 was built You should also make sure to have a copy of the MC68HC11 Reference Manual since it contains detailed descriptions and examples for many of the hardware subsystems 2 6 MIGRATING FROM 68HC11 If you are already experienced with the 68HC11 family of microcontrollers writing programs for the HCS12 family will not present a big challenge don t throw away your HC11 Reference Manual the trusty pink book In fact you can use your existing 68HC11 assembly code and re assemble it to run on the CPU12 core but there are a few things to keep in mind Assembler syntax You may need to edit your source file to conform to the syntax and directives of the HC12 a
21. nts before transferring control to the Main Compile and link the program fixing any syntax errors that may have cropped up Ensure that the Project Options Device Configuration drop down box points to the 9S12C32 Flash Mode This sets the link address to start the code section at 0x4000 and the stack at top of RAM 0x4000 4 5 USING A BDM POD If you have a BDM pod you can erase the resident monitor program completely This will free up all the MCU resources for your program most importantly the SCI Without the monitor in place the RAM will be at the default location following reset so make sure to use the correct compiler linker settings Also the PLL won t be enabled so the bus speed will be 4 MHz 4 66 AUTOMATING S RECORD CONVERSION IN ICC12 You may have to convert the s record file to get it into the proper format for your BDM pod to load correctly ICC1i2 has a nice feature at Project gt Options gt Compiler gt ExecuteCommandAfterBuild where you can add the SRECCVT command mentioned earlier Use the following command line sreccvt exe m C0000 FFFFF 32 Ip o outfile s2 infile s19 where infile refers to the file you are converting and outfile is the result 10 NanoCore modules are shipped from the factory with a Demo program loaded into its memory This program is useful for familiarizing yourself with the hardware features of the MCU It was written in assembler and the sourcecode can be found on our Product CD or
22. of the device s available RAM 4 External devices attached to the multiplexed external bus interface are not support ed 15 SERIAL PORT USAGE In order for this monitor to function the SCIO serial interface is used It is assumed that the monitor has exclusive use of this interface User application code should not implement communications on this serial channel This monitor accommodates RS232 serial communi cations through SCIO at 115 2 kbaud For applications requiring the use of SCIO you should purchase a BDM pod which allows for more advanced debugging VECTOR REDIRECTION AND INTERRUPT USE Access to the user vectors is accomplished via a jump table located within the monitor memory space This table points all interrupt sources to a duplicate vector table located just below the monitor F780 F7FE The monitor will automatically redirect vector programming operations to these user vectors The user s code should therefore continue to implement the normal non monitor vector locations FF80 FFFE If execution of an interrupt with an un programmed vector is attempted behavior is undefined For this reason the user is strongly encouraged to implement a software trace for all vectors as is good programming practice The monitor depends on interrupts being available for monitor re entry after GO or TRACE commands Therefore it is important that the user application executes with interrupts enabled 16 APPENDIX B UBUG12
23. omatically adjust them when your s record is loaded 2 the monitor relocates RAM to the address range 0x3800 to 0x4000 from the default location after MCU reset of 0x0000 to OxO7FF On NanoCore12MAXC128 the RAM is remapped to the range 0x3000 to 0x4000 3 the monitor program enables the phase locked loop PLL so the module runs at 24Mhz instead of the MCU s default startup speed of 4Mhz 4 the user code must clear the CCR I Bit e g via the CLI instruction in assembler or the INTR_ON directive in ICC12 5 the SCI cannot be used by the user program when in LOAD mode since it is dedi cated to the monitor program 6 COP cannot be disabled in LOAD mode 4 2 WRITING A SIMPLE C PROGRAM IN ICC12 Before starting you ll need to set up your compiler settings as follows Program Memory 0x4000 0x7FFF 0xC000 0xFFFF Data Memory 0x3800 use 0x3000 if using a C128 module Stack Pointer Ox3FCO Note that the Data Memory and Stack Pinter addresses shown are valid only for a device with a resident monitor since the monitor remaps the RAM following reset If you are writing software for a completely blank chip and loading it in via a BDM pod you ll need to change these values to work with the default RAM address range see the MCU datasheet Flashes Docking Module or School Board LED D2 twice a second include lt hcs12c32 h gt define DUMMY_ENTRY void void OxFFFF pragma nonpaged_function _startextern void
24. online our Support Library if you would like to examine or modify it If you ve already erased the demo program you may use uBug12 to re load it Then follow the relevant steps in the QuickStart Guide to open HyperTerminal and achieve the display shown below M68M0D912C32 HyperTerminal i Emx Fie Edit View Call Transfer Help Del 215 del ei IRQ is disabled M68M0D912C32 DEMO PROGRAM COMMAND MENU VI ou gt CLEAR PORT T OUTPUTS gt SHOW PORT E STATUS gt FLASH LED CONNECT TO PTO gt SHOW PORT PTAD STATUS gt SHOW PORT M STATUS gt SHOW PORT T STATUS gt SHOW 10 bit REAL TIME ANALOG VALUES TO gt TOGGLE THE SELECTED T PORT LINE C E F H M T R 0 7 Connected 0 00 19 auto detect 9600 8 N 1 SCROLL CAPS Wa Capture Print echo 5 1 Executing Demo Commands eType the digit O repeatedly and observe that LED D2 toggles on and off eType the digit 1 repeatedly and observe that LED D3 toggles on and off eType the letter F to cause LED D2 to flash twice Typing E H M or T will cause a hex number to be displayed whose bit values represent the logic levels of the respective pins If the pins are unconnected to external circuitry they will assume a logic 1 level due to internal pullup resistors 5 2 A Simple Audio Circuit vec Connect a simple audio transducer cir cuit as shown and type the letter F LED D2 HR will flash twice and two audible beep tones on a will b
25. ssembler you ll be using There are several assemblers available e g AS12 MiniIDE IASM12 MCUez and each has its own syntax to be aware of Register Block Instead of 1000 the register block default location is 0000 through 03FF and there are a few hundred registers You ll need to locate the relevant registers for the subsystems you plan to use and make sure they are properly configured The good news is that you can safely ignore registers for the subsystems you are not using the reset defaults are at safe settings RAM location Following reset the memory map configuration has the register block overlapping RAM starting at 0000 with registers taking priority so the first 1K bytes of RAM are not usable In order to free up all of the RAM the monitor program re maps RAM to start at 3800 and go to 3FFF via the RAMinit register This means you ll need to initialize the Stack Pointer to 4000 on the HCS12 the stack pointer points to the address following the top of the stack High speed Bus The default bus speed is half the crystal frequency of 8 MHz so it is 4 MHz If you enable the PLL it will be even higher up to 24 MHz This will mean changing some initialization values for control registers and revising delay constants if you are using any software timing loops in your old 68HC11 code I O Ports The digital I O ports on the HCS12 are more flexible than ever Besides selecting the direction of each port pin via a Data
26. t you are using usually 1 or 2 The Module is now ready for your commands see Appendix B for a full list of UBug12 commands o ef o ooo o o To download one of the supplied example programs into flash and execute it follow these steps Type fbulk lt enter gt at the uBug12 prompt to erase any existing program Type fload lt enter gt From the displayed file browser select one of the example program s output files s2 or s28 file After loading has finished move switch SW2 to the RUN postion and press the Reset button SW1 The program will run If you wish to debug the program move SW2 back to the LOAD position and press Reset The uBug12 prompt will appear Use uBug12 commands to debug your code see Appendix B for a full list of uBug12 commands 19 1 0 2 1 POWER OPTIONS A DC power supply is included with most bundle configurations It is the recom mended power source when you re starting out If for some reason it s not convenient eg you don t want an extension cord trailing around behind your robot gt there are a couple of alternatives Option 1 connect a DC voltage of 6 Volts or more absolute maximum 24 VDC via the external power connector J1 on the Docking Module or School Board If you aren t using a Docking Module or School Board apply a voltage of 6 to 12 V between the Vin positive pin and the Vss Ground pin on the NanoCore module Refer to the NanoCorei2 pinout diagrams on the back
27. uding FLASH EEPROM memory read or modify CPU registers go halt or trace single instructions In order to allow a user to specify the address of each interrupt service routine this monitor redirects interrupt vectors to an unprotected portion of FLASH just below the protected monitor program This monitor is intended to be device unspecific this single application with very slight modification should execute on any HC9S12 derivative A user on a tight budget can evaluate the MCU by writing programs programming them into the MCU then debug using only a serial I O cable and free software uBug12 for their personal computer This monitor does not use any RAM other than the stack itself The COP watchdog is utilized for a cold reset function user code should not disable the COP ie by writing 0x00 to COPCTL This development environment assumes you reset to the monitor when you are going to perform debug operations If your code takes control directly from reset and then an SCIO interrupt or a SWI attempts to enter the monitor the monitor may not function because SCIO the phase locked loop PLL and memory initialization registers may not be initialized as they would be for a cold reset into the monitor There is no error handling for the PLL If the frequency source is missing or broken the monitor will not function The monitor sets the operating speed of the MCU to 24 MHz Modification of the MCU speed by the user with out considerations for
28. ut and many of their addresses have changed Gone are the Vfp genera tor and flash voltage switch since the new flash technology uses 5V and has built in self timed algorithms for program and erase functions But your s records must contain an even number of bytes and begin on an even address boundary if you re going to burn them into flash Some assemblers will generate this format for you but others such as AS12 don t In the latter case you ll need to use the Freescale utility called SRECCVT 3 1 3 VOLT OPERATION One of the nice features of the MCU is that it can operate on 3 to 5 V while maintaining full bus speed capability To support 3 Volt operation the Docking Module incorporates an adjustable regulator whose output voltage is set by a resistive voltage divider The circuit has been designed such that simply inserting a shorting jumper causes the regulator s output to shift from 5V to 3 3V Note If you aren t using a Docking Module e g you re just plugging the DIP module into a breadboard you ll need to supply your own 3 Volt regulated supply to the Vcc pin to take advantage of 3 Volt mode When operated at 3V there are a few precautions that should be noted however The logic pins are not 5V tolerant so you will need to take the necessary steps to prevent damage to the I O pins of the MCU Also the maximum VRH voltage is limited to 3 3V so any external voltage or precision voltage reference you supply for us
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