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MCF51QE Flash Erase and Programming

Question asked by sebasira on May 13, 2011
Latest reply on May 20, 2011 by sebasira

Hello everybody! How are you doing?

I hope you're well


I'm developing an application that store user data in the internal flash memory. I'm using routines from AN3942, which are:


char Flash_SectorErase(unsigned long *FlashPtr)

char Flash_ByteProgram(unsigned long *FlashStartAdd,unsigned long *DataSrcPtr,unsigned long NumberOfBytes)


Well, first of all, I've notice that argument NumberOfBytes, should be NumberOfDWord, because the Flash_ByteProgram routine write as many 4bytes as NumberOfBytes... So let's say that you want to write 4 bytes at address 0x2000 then function call should be:


Flash_ByteProgram(0x2000, data_ptr, 1)


Please, try it your self and let me know. I've notice that because the routine writes 4 times the length I want to write.



On the other hand, I can't program an address, and then erase it and progam it again... 


Flash_Erase(0x2000)Flash_ByteProgram(0x2000, "TEST", 1)then when some event happens, I callFlash_Erase(0x2000)Flash_ByteProgram(0x2000, "LONG", 1)


After programming "TEST" I go check the address 0x2000 and there it is, "TEST" is written at that address.

Then I put a breakpoint when the event happens and call Flash_Erase. This routine returns error code 0 (no error), but I look at address 0x2000 and "TEST" is still there... I assume, when erased, 0xFF 0xFF 0xFF 0xFF should be there instead... After Flash_Erase, Flash_ByteProgram is executed, again error code is 0, but the new value it's not written...


What could be happenning?


Just want to let you know that I do not run it step by step... I set the breakpoint, and the let it run when breakpoint is reached.... It didn't work (flash wasnt re-programmed) so then I ran stepping over the routines just to see what do they returned.


Thanks in advance! I hope you can help me here