I have problems to read the internal flash.

ralf1694 — Mon, 25 Apr 2016 11:56:53 GMT

Hi. I have problems with my MK22FX512VLH12. I save my data by powerfail on my internal flash and sometimes I can not save all my data. For example my flash have this entries: AA AA AA AA BB BB BB BB FF FF FF FF FF FF FF FF.

The first 8 bytes are ok but the last 8 bytes do not save on the flash. If I want to read the last 4 bytes (FF FF FF FF), I get an Bus Error. On the Comand window from uVision stands: Cannot access Memory (@ 0x10004210, Read, Acc Size: 4 Byte). I read the data with a normal pointer. Why I can not read this address?

If all data stored by powerfail I have no problems.

Re: I have problems to read the internal flash.

jeremyzhou — Tue, 26 Apr 2016 06:30:39 GMT

Hi Ralf,

I was wondering if you can share the thorough steps of your implementation, then I can replicate the issue on my site and it can help me to figure out the root of cause.

Hope it helps.
Have a great day,

Ping

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Re: I have problems to read the internal flash.

ralf1694 — Wed, 27 Apr 2016 21:59:35 GMT

Thanks. I post the code on monday.

Re: I have problems to read the internal flash.

ralf1694 — Mon, 02 May 2016 06:53:12 GMT

Hi. Here is my code.

uint32_t oftenWrittenDataInSectorOffset = 0x20;

uint32_t oftenWrittenDataSectorOffset = 0x1000;

uint32_t oftenWrittenDataFlashBaseAddress = 0x10000000;

uint32_t oftenWrittenDataCounter = 0;

uint32_t fewWrittenDataInSectorOffset = 0x40;

uint32_t fewWrittenDataSectorOffset = 0x1000;

uint32_t fewWrittenDataFlashBaseAddress = 0x10010000;

Whey I detect a power fail, I execute this function:

uint32_t writeDataOnFlash(uint32_t dest, uint32_t size){

int32_t checkSum = 0;

uint8_t oftenWrittenData[24] = {0};

uint64_t cast;

uint8_t *pData;

uint32_t ret;

if(size > 24){

//Size to large

return ERR_SIZE;

}

for(int i = size; i > 0; i--){

//read data and calculate checkSum

pData = (uint8_t *) ((dest-1) + i);

oftenWrittenData[i-1] = *pData;

checkSum += *pData;

}

pData = (uint8_t *) &cast;

for(int i = 0; i < 4; i++){

//counter write to cast variable

*pData = *(((unsigned char *)(&oftenWrittenDataCounter))+i);

checkSum += *pData;

pData++;

}

for(int i = 0; i < 4; i++){

//first value write to cast variable

*pData = *(((unsigned char *)(&oftenWrittenData))+i);

pData++;

}

//write counter and first value on flash memory

ret = FlashProgram(&ssdConfig, destOftenWrittenData, 8, (uint8_t*) &cast, pFlashCommandSequence);

if(ret != 0){

//error write on flash memory

return ERR_WRITE;

}

pData = (uint8_t *) &cast;

for(int i = 4; i < 12; i++){

//write 2. value and 3. value to cast variable

*pData = *(((unsigned char *)(&oftenWrittenData))+i);

pData++;

}

//write 2. value and 3. value on flash memory

ret = FlashProgram(&ssdConfig, destOftenWrittenData+8, 8, (uint8_t*) &cast, pFlashCommandSequence);

if(ret != 0){

//error write on flash memory

return ERR_WRITE;

}

pData = (uint8_t *) &cast;

for(int i = 12; i < 20; i++){

//write 4. value and 5. value to cast variable

*pData = *(((unsigned char *)(&oftenWrittenData))+i);

pData++;

}

//write 4. value and 5. value on flash memory

ret = FlashProgram(&ssdConfig, destOftenWrittenData+16, 8, (uint8_t*) &cast, pFlashCommandSequence);

if(ret != 0){

//error write on flash memory

return ERR_WRITE;

}

pData = (uint8_t *) &cast;

for(int i = 20; i < 24; i++){

//6. value write to cast variable

*pData = *(((unsigned char *)(&oftenWrittenData))+i);

pData++;

}

for(int i = 0; i < 4; i++){

//checkSum write to cast variable

*pData = *(((unsigned char *)(&checkSum))+i);

pData++;

}

//write 6. value and checkSum on flash memory

ret = FlashProgram(&ssdConfig, destOftenWrittenData+24, 8, (uint8_t*) &cast, pFlashCommandSequence);

if(ret != 0){

//error write on flash memory

return ERR_WRITE;

}

//get next free flash memory

getOftenWrittenDataFlashAddress();

return OK;

}

Sometimes I have no time to save the 6. value and the checkSum. My flash memory is in this case FF FF FF FF FF FF FF FF for the 6. value and the checksum.

When I make a reset, I execute this function:

When I try to read the checksum with a normal pointer I get an Bus Error. (readCheckSum = *pCounter;)

uint32_t readDataFromFlash(uint32_t dest, uint32_t size){

int32_t *pCounter;

uint8_t *pByteCounter;

int32_t lastEntry;

int32_t readCheckSum;

int32_t proveCheckSum = 0;

uint8_t *pDest = (uint8_t *) dest;

if(size > 24){

//try to read to much bytes from flash

return ERR_SIZE;

}

//last entry is next free flash address - offset of stored data

lastEntry = destOftenWrittenData - oftenWrittenDataInSectorOffset;

uint32_t nextValue = 0;

do{

//find right data

if(lastEntry == 0x0FFFFFE0){

//transition from first sector to last sector

lastEntry = 0x10000000;

pCounter = (int *) (lastEntry + (oftenWrittenDataInSectorOffset - 0x4));

readCheckSum = *pCounter;

if(readCheckSum == -1){

lastEntry = 0x1000FFE0;

}

//read checksum

pCounter = (int *) (lastEntry + (oftenWrittenDataInSectorOffset - 0x4));

readCheckSum = *pCounter; // Here I get the error!

if(readCheckSum == -1){

//data empty

proveCheckSum = 0;

lastEntry -= oftenWrittenDataInSectorOffset;

nextValue++;

continue;

}

//calculate checksum

for(int j = 0; j < 28; j++){

pByteCounter = (unsigned char *) (lastEntry + j);

proveCheckSum += *pByteCounter;

}

//found right data

if(readCheckSum == proveCheckSum){

//set next value to 128, so the do while reach the end

nextValue = 128;

}else{

proveCheckSum = 0;

}

lastEntry -= oftenWrittenDataInSectorOffset;

nextValue++;

}while(proveCheckSum != readCheckSum && nextValue < 128); //prove checksum; if all checksums (128) in sector wrong -> break

if(proveCheckSum == readCheckSum){

//checksum right -> read data

for(int i = 4; i < size+4; i++){

pByteCounter = (unsigned char *) ((lastEntry + oftenWrittenDataInSectorOffset)+i);

*(pDest + (i-4)) = *pByteCounter;

}

return OK;

}

return ERR_NO_VALID_DATA;

}

Re: I have problems to read the internal flash.

ralf1694 — Tue, 03 May 2016 19:07:46 GMT

In the original FlashProgram() function are a few lines between disableInterrupts() and enableInterrupts().

I am seeing that someone comment it out.

When I am writing to the D-Flash and an Interrupt occurs (ISR in P-Flash), can it corrupt my data in the D-Flash?

And when I am trying to read them, then i get a Bus Error?

Re: I have problems to read the internal flash.

jeremyzhou — Wed, 04 May 2016 07:22:11 GMT

Hi Oliver,

After had a brief look through your code, I'd highly recommend you to use the C90TFS software driver, and you can find the some flash demos in the KSDK, please refer to them for details.

KSDK: Software Development Kit for Kinetis MCUs|NXP
Have a great day,
Ping

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