Philips ARM LPC microcontroller family
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1. LDMFD SP RO R2 R14 Pop link register and register workspace MOV PC LR jump_to_IAP LDR R12 IAP_ ENTRY BX R12 Branch to Ox7FFFFFF1 and Change to thumb instruction set END To call the IAP function we branch and link BL to a small routine jump_to_IAP and then we Call the IAP function using BX By performing BL jump_to_IAP we get R14 to point to the next instruction and then using BX instruction we can directly jump to the IAP routine and change to Thumb instruction set If user wishes to call the IAP routine using Thumb code then the code could be as follows AREA thumb_code CODE CODE16 EXPORT initial this routine could be linked to other routines using this global symbol IAP ENTRY EQU Ox7ffffff1 IAP entry point COMMAND EQU Ox Command table pointer RESULT EQU 0X Result table pointer Main 9397 750 14073 Koninklijke Philips Electronics N V 2004 All rights reserved Application note Rev 02 25 October 2004 5 of 10 Philips Semiconductors AN1 0256 9397 750 14073 Philips ARM LPC microcontroller family Initial PUSH RO R2 R14 Push the register workspace and link register into stack LDR RO COMMAND Set the pointers for LDR R1 RESULT command and result tables Once the pointers are set the command code and its respective parameters need to be stored in the command table An example is provided below where the command code 54 for IA2. 3 IAP code in Assembly 9397 750 14073 The IAP routine may be called in the following way using ARM assembly code This code was developed using the ARM Developer Suite ADS1 2 The assembler directives will change depending upon the assembler the end user will use AREA arm_code CODE CODE32 EXPORT initial This routine could be linked to other routines using this global symbol IAP ENTRY EQU Ox7ffffffl1 IAP entry point COMMAND EOU Okusne Command table pointer RESULT EQU OX Result table pointer Main initial STMFD SP RO R2 R14 Push the register set and link register into stack LDR RO COMMAND Set the pointers for LDR R1 RESULT command and result tables Once the pointers are set the command code and its respective parameters need to be stored in the command table An example is provided below where the command code 54 for IAP command Read Part ID is stored into the command table MOV R2 0x36 STR R2 R0 Please look below after END for description for how the IAP routine is called Koninklijke Philips Electronics N V 2004 All rights reserved Application note Rev 02 25 October 2004 4 of 10 Philips Semiconductors AN1 0256 Philips ARM LPC microcontroller family BL jump _to IAP At this point user has to analyze the result table and take action depending upon the status code returned by the IAP routine Code not shown
3. 7 750 14073 Philips ARM LPC microcontroller family performance When the product is in full production status Production relevant changes will be communicated via a Customer Product Process Change Notification CPCN Philips Semiconductors assumes no responsibility or liability for the use of any of these products conveys no licence or title under any patent copyright or mask work right to these products and makes no representations or warranties that these products are free from patent copyright or mask work right infringement unless otherwise specified Application information Applications that are described herein for any of these products are for illustrative purposes only Philips Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or modification Koninklijke Philips Electronics N V 2004 All rights reserved Application note Rev 02 25 October 2004 9 of 10 Philips Semiconductors AN1 0256 Philips ARM LPC microcontroller family 6 Contents 1 Introduction 000 cece eee 3 2 IAP code in C jisccce ccc ee eee reece 3 3 IAP code in Assembly 0 0000 4 4 Using the ARM Developer Suite ADS 1 2 TODS sic te cere cake nee eae Ee eee ees 7 5 Di claiM tS errioa resaman no See 9 Koninklijke Philips Electronics N V 2004 All rights are reserved Reproduction in whole or in part is p
4. AN10256 Philips ARM LPC microcontroller family Semiconductors Rev 02 25 October 2004 Application note P Document information Info Content Keywords ARM LPC IAP Absiract This application note provides code samples in C and assembly which will help the end user use the In Application Programming IAP technique for programming the on chip Flash Philips Semiconductors AN1 0256 J Philips ARM LPC microcontroller family Revision history Rev Date Description 02 20041025 e The format of this application note has been redesigned to comply with the new presentation and information standard of Philips Semiconductors e Added a note on enabling the ARM Thumb interworking option in the compiler assembler e Corrected the data type mismatch between the IAP function call and pointer initialization 01 20031212 Initial version 9397 750 14073 Koninklijke Philips Electronics N V 2004 All rights reserved Application note Rev 02 25 October 2004 2 of 10 Philips Semiconductors AN1 0256 Philips ARM LPC microcontroller family 1 Introduction In Application IAP programming is the performing of erase and write operations on the on chip Flash memory as directed by the end user application code The Flash boot loader provides the interface for programming the Flash memory For detailed information on the In Application Programming please refer to the Flash Memory System and Programming ch
5. P command Read Part ID is stored into the command table MOV R2 0x36 STR R2 RO Please look below after END for description for how the IAP routine is called At this point user has to analyze the result table and take action depending upon the status code returned by the IAP routine Code not shown POP RO R2 R3 BX R3 Pop the link register contents and go back to ARM mode jump_to_IAP LDR R2 IAP_ ENTRY BX R2 END The differences in the Thumb code as compared to the ARM code being the assembler directive CODE16 and the push and pop instructions for the stack Koninklijke Philips Electronics N V 2004 All rights reserved Application note Rev 02 25 October 2004 6 of 10 Philips Semiconductors AN1 0256 Philips ARM LPC microcontroller family 4 Using the ARM Developer Suite ADS 1 2 tools 9397 750 14073 There is one more way of calling the IAP routine using the symbol definitions symdefs file but this is specific to the ARM development tools The IAP routine could be looked as an image residing in Flash Now an image residing in RAM can access the global symbols of this image residing in Flash using the symdefs file The symdefs file can be considered to be an object file which contains symbols and their values Please refer to Chapter 4 in the ARM Developer Suite Linker and Utilities Guide for detailed information on accessing symbols The symdefs file could be def
6. apter in the ARM LPC device User Manual In this application note code samples are provided in C and assembly which show how IAP may be used The IAP routine resides at Ox7FFFFFFO and is Thumb code 2 IAP code inC 9397 750 14073 The IAP function could be called in the following way using C This section is taken from the User Manual Define the IAP location entry point Since the Oth bit of the IAP location is set there will be a change to the Thumb instruction set when the program counter branches to this address define IAP LOCATION 0x7ffffff1 Define data structure or pointers to pass IAP command table and result table to the IAP function unsigned int command 5 unsigned int result 2 or unsigned int command unsigned int result command unsigned int 0x result unsigned int 0x Define pointer to function type which takes two parameters and returns void Note the IAP returns the result with the base address of the table residing in R1 typedef void IAP unsigned int unsigned int IAP iap entry Setting function pointer jap entry IAP IAP LOCATION Whenever user wishes to call IAP within the application the following statement could be used lap_entry command result Koninklijke Philips Electronics N V 2004 All rights reserved Application note Rev 02 25 October 2004 3 of 10 Philips Semiconductors AN1 0256 Philips ARM LPC microcontroller family
7. ined as follows for the IAP routine lt SYMDEFS gt ARM Linker ADS1 2 Build 805 Last Updated Fri Jun 06 15 46 24 2003 ox7ffffff0 T iap entry The first 11 characters lt SYMDEFS gt of this text file recognizes this file as a symdefs file We then provide the symbol information with regard to the IAP routine in the second line This file could then be linked to user application using the F option at command line for the ARM linker To do this on the Metrowerks CodeWarrior open the Debug settings window for the project then click on ARM linker and then Equivalent Command Line could be seen under Output tab where the following option could be added F C symdefs where symdefs is the symdefs file Once the symdefs file has been defined and added the to the project using the F option then in the user application the following needs to be done Only C code is shown as an example Define data structure or pointers for IAP command table and result table unsigned int command 5 unsigned int result 2 or unsigned int command unsigned int result command unsigned int 0x result unsigned int 0x Call IAP routine lap_entry command result As seen above iap_entry does not have to be defined anywhere in the application as the linker now knows it is been defined in the image residing in Flash through the symdefs file Remark If the end user application which runs from SRAM is ARM c
8. ode and if the IAP function is called it may lead to an exception if the compiler assembler options are not set properly While compiling the code user needs to instruct the compiler that the application Koninklijke Philips Electronics N V 2004 All rights reserved Application note Rev 02 25 October 2004 7 of 10 Philips Semiconductors AN1 0256 O Philips ARM LPC microcontroller family is going to make a call to Thumb code IAP code residing in Flash is Thumb code Most of the compilers assemblers will have an option called ARM Thumb interworking and this needs to be enabled by the end user 9397 750 14073 Koninklijke Philips Electronics N V 2004 All rights reserved Application note Rev 02 25 October 2004 8 of 10 Philips Semiconductors AN10256 5 Disclaimers Life support These products are not designed for use in life support appliances devices or systems where malfunction of these products can reasonably be expected to result in personal injury Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application Right to make changes Philips Semiconductors reserves the right to make changes in the products including circuits standard cells and or software described or contained herein in order to improve design and or 939
9. rohibited without the prior written consent of the copyright owner The information presented in this document does not form part of any quotation or contract is believed to be accurate and reliable and may be changed without notice No liability will be accepted by the publisher for any consequence of its use Publication thereof does not convey nor imply any license under patent or other industrial or intellectual property rights Date of release 25 October 2004 Document number 9397 750 14073 Published in The U S A
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