TN229 BL1800 BL2100 - Datasheet Archive

 

Flash Corruption with writeUserBlock Function If a user program uses the library function writeUserBlock(), a Dynamic C library

 

TN229 TN229 Flash Corruption with writeUserBlock Function If a user program uses the library function writeUserBlock(), a Dynamic C library error present in versions 7.20-7.25 can cause corruption or incorrect placement of the System ID block and/or User block areas with any board type (Rabbit or custom) that has a version 3 or 4 System ID block. The System ID block is a reserved area in the top of flash memory that contains important information such as product ID, and on some Ethernet-enabled boards, media access control (MAC) address. The User block is an area of flash reserved for user data and calibration constants. These features are explained in detail in the Rabbit Designer's Handbooks. The information we are most concerned with here is the product ID, the MAC address and calibration constants. The only difference between a version 3 or 4 ID block and earlier versions is that writeUserBlock() mirrors the System ID and User blocks in versions of Dynamic C 7.20 and above. Mirroring provides an extra measure of flash write protection in case of power failure while writing. writeUserBlock() will work correctly with version 3 or 4 System ID blocks and versions 7.26 and higher of Dynamic C. Symptoms The IDBLOCK_RECOVERY.C utility program accompanying this document (TN229 TN229.zip) will test whether a board has a corrupted version 3 or 4 System ID block and attempt to recover it. Although the block contains other information, the only two items that can cause compilation or run time problems if the information is incorrect are the product ID and MAC address. Product ID The consequence of not having a correct product ID is that Dynamic C will misidentify the board type and incorrectly set the internal macro _BOARD_TYPE_ that is used to conditionally compile code in several libraries. This will usually generate a compiler error when trying to #use a board-specific library or compile a board-specific function. MAC Address The consequence of not having a valid MAC address is that user programs won't be able to communicate over Ethernet. Calibration Constants Incorrect or missing calibration constants in the User block will cause incorrect A/D D/A conversions. 022-0077 Rev. C www.rabbit.com 1 Affected Products Any board with a version 3 or 4 ID Block installed may experience problems due to the library error described above; a board's ID Block version can be checked with the IDBLOCK_REPORT.C utility program accompanying this document. In particular, boards with types included in the following list were shipped with a version 4 ID Block prior to the introduction of Dynamic C version 7.26. · · · · · · · · · · BL20x0 BL21x0 (may also have corrupted or mislocated calibration constants) OP67x0 (MAC address is not a problem because it is in EEPROM, not flash) OP68x0 RCM20x0 RCM21x0 RCM30x0 RCM31x0 SR91x0 CPU board TCP/IP Development Board (MAC address is not a problem because it is in EEPROM, not flash) Note: x refers to any digit. Trivial Case: RCM20x0 None of the information in the RCM20x0's System ID block is required for correct operation because there is no MAC address and no board-specific library or code for this product. However, if your compiler version is older than 7.02C and it is not a Premier version of Dynamic C, you will see a compiler error if a correct product ID is not present because the product ID will default to 0x100 (JackRabbit/BL1810 board) and JackRabbit specific libraries will try to #use JackRabbit libraries that weren't included in all Dynamic C versions until 7.02. This is easily fixed by commenting out the #use statements in default.h for the BL1800 BL1800 libraries. If you upgrade Dynamic C, this will not be an issue. Resolution Libraries correcting the error in writeUserBlock() were introduced and released in Dynamic C version 7.26. Libraries correcting the writeUserBlock() error for versions 7.20, 7.21, and 7.25 accompany this document in a zip file. You should replace the libraries in your Dynamic C version with the like-named libraries for that version. If you have already run a program that uses writeUserBlock() with version 7.20, 7.21, or 7.25, and are experiencing any of the described symptoms, you will need to run the diagnostic repair utility and/or write ID block utilities described below to recover or replace the system ID block information as applicable. If your board is a BL21xx type with calibration constants and the diagnostic/repair utility reports that it was unable to find or recover valid calibration constants, you must recalibrate your analog I/O using sample programs or send it back to Rabbit for recalibration. If a product has an intact MAC address, or the MAC address is in EEPROM, then Ethernet will still work correctly. A simple library change will set the _BOARD_TYPE_ macro correctly if the product ID is corrupted: #undef _BOARD_TYPE_ and #define it to the desired value in \LIB\DEFAULT.H. However, this change will have to be propagated if you upgrade Dynamic C. A more permanent fix is to change the system ID block. 2 www.rabbit.com TN229 TN229 Diagnostic/Repair Utility The diagnostic/repair utility program accompanying this document, IDBLOCK_RECOVERY.C, will do the following. 1. Check the installed System ID block version to ensure that it is version 3 or 4; if not it will quit without making changes. 2. If a BL21xx board, if needed and if possible, recover calibration constants. 3. If a User block exists, and only if necessary, copy the valid User block data to the appropriate location. 4. If a System ID Block exists, and only if necessary, copy the valid version 3 or 4 System ID block data to the appropriate version 2 System ID block location. 5. Change the ID block version from 3 or 4 to 2. Directions for running the program are in the comment block at the top of the program. If the program reports an unrecoverable System ID block, follow the instructions in the next section, "Rewriting the System ID Block." If the program reports that it was unable to recover calibration constants on a BL21xx board follow the instructions in the section, "Recalibrating BL21xx Series Boards." Rewriting the System ID Block To rewrite the system ID block, you need to run WRITE_IDBLOCK.C provided in the zip file accompanying this document. Directions for running the program are in the comment block at the top of the program. It is important to enter the correct product ID and MAC address if used. By default, this program will create a version 2 System ID block if compiled using Dynamic C version 7.25 or earlier. Recalibrating BL21xx Series Boards If the IDBLOCK_RECOVERY.C program reports that it cannot find or recover calibrations constants for a BL21xx board, you must recalibrate using \SAMPLES\BL2100 BL2100\ADC\AD_CALIB.C and \SAMPLES\BL2100 BL2100\DAC\DACAL.C or return the board to Rabbit Semiconductor for recalibration. TN229 TN229 www.rabbit.com 3