32- bit CRC Calculation of flash for STM32F070xB

[Priyadarshini Solanki]

Posted on January 25, 2018 at 06:42

I am using

♯

, where I tried to calculate the 32- bit CRC of my flash using

♯

register.

How I can ensure if the CRC calculation of my flash is correct.

CRC Configuration I used is :

hcrc.Instance = CRC;

hcrc.Init.DefaultPolynomialUse = DEFAULT_POLYNOMIAL_ENABLE;

hcrc.Init.DefaultInitValueUse = DEFAULT_INIT_VALUE_ENABLE;

hcrc.Init.InputDataInversionMode = CRC_INPUTDATA_INVERSION_NONE;

hcrc.Init.OutputDataInversionMode = CRC_OUTPUTDATA_INVERSION_DISABLE;

hcrc.InputDataFormat = CRC_INPUTDATA_FORMAT_WORDS;

/*ROM address*/

&sharpdefine ROM_START (( uint32_t * ) 0x08000000 )

&sharpdefine ROM_END (( uint32_t * ) 0x0801FFFB )

Calculated CRC is stored in the variable.

#flash #crc #stm32f070xb #crc->dr #crc-32

[Tesla DeLorean]

Posted on January 25, 2018 at 16:48

>>How I can ensure if the CRC calculation of my flash is correct.

Load the binary externally, and do the computation?

https://www.iar.com/support/tech-notes/general/calculate-crc32-as-in-stm32-hardware-v.5.50-and-later/

 

 

https://community.st.com/0D50X00009XkWntSAF

 

[Priyadarshini Solanki]

Posted on January 29, 2018 at 07:31

ROM_END = 0x08000000

ROM_START = 0x0801FFFB

ROM_SIZE = ROM_END -ROM_START

FLASH_WORD_SIZE = 4

CRC_Calculate(&hcrc, (uint32_*) 

pBuffer[index]

,uint32_t BufferLength){

   uint32_t index = 0U;

   uint32_t temp = 0U;

    CRC_DR_RESET(hcrc);

   for(index = 0U; index <

ROM_SIZE / FLASH_WORD_SIZE

; index++){

      hcrc->Instance->DR = pBuffer[index];

   }

   temp = hcrc->Instance->DR;

}

void main(void){

   .....

   uint32_t currentRomDataCrc;

   currentRomDataCrc = CRC_Calculate(&hcrc,

0x08000000,(uint32_t)( ROM_SIZE / FLASH_WORD_SIZE));

   if (currentRomDataCrc == __checksum)

   {

         //TODO

   }

   else

   {

         //TODO

   }

}

RESULT:

      

currentRomDataCrc  = 

0x3BE8893E      //Location: 0x200001B8

       __checksum = 0x49354A9E                  //Location: 0x08003578

I am not getting the same result in calculated CRC and __checksum.

[Tesla DeLorean]

Posted on January 29, 2018 at 18:19

So make sure it is going over exactly the same words. Check the computation externally with your own code reading the binary. I could check it but you'd need to provide the binary for me to inspect.

The size should be computed like this

ROM_SIZE = ((ROM_END - ROM_START) + 1) // The way you describe the start/end points describes N-1 rather than N bytes

If you CRC the 0x20000/4 words the residual should by ZERO, at 0x1FFFC/4 words the CRC computed by both sides should match the word at 0x0801FFFC

I'm not using IAR.

I'm open to reasonable offers for my time to work on this.