Calculate crc in spc5studio and SPC58ECxxxx MCUs

[PLEE.2]

I am using spc5studio and SPC58EC80E1.

i import crc sample from application library.

i set CRC Settings at low level Drivers component RLA

- CRC-32, Polymonial seed 0x4c11db7, reset = 0xFFFFFFFF

and firmware code

​-----------------------------------------------------------------------------------------------------

const CRCContextConfig *crc_ctx_config[] = {

 &crc_context_config_contex_crc32,

};

  (void)crc_lld_start(&CRCD1);

  (void)crc_lld_start_context(&CRCD1, 0, crc_ctx_config[0]);

  if (crc_lld_calc(&CRCD1, 0, startAddress, (uint32_t)length, &calculatedCRC) != CRC_NO_ERROR) {

   osalThreadDelayMilliseconds(100);

  }

  (void)crc_lld_stop_context(&CRCD1, 0);

  (void)crc_lld_stop(&CRCD1);

-----------------------------------------------------------------------------​

The code for the window is as follows.

uint Polynominal = 0x04C11DB7;

uint InitValue = 0xFFFFFFFF;

int i= 0, j = 0;

uint CRC = 0xFFFFFFFF;// InitValue;

for (i = 0; i < nByte; i++)

{

byte ch = c[i];

for (j = 0; j < 8; j++)

{

CRC = (uint)(ch ^ CRC);

if ((CRC & 0x80000000) != 0)

{

CRC = (CRC <<1) ^ Polynominal;

}

else

{

CRC <<= 1;

}

}

}

---------------------------------------------------------------------------------​​

later

​I checked crc value the image of flash, but it is different from the CRC-32 calculation in windows program.

I want to know how to calculate the application library.

Or, I would appreciate it if you could let me know if my code is wrong.

thanks.

regards.

[Erwan YVIN · Accepted solution]

Hello ,

Interesting issue 😉

Could you try your software code in SPC58EC ?

Could you check this application SPC560Pxx OS-Less CRC Test Application for Discovery

there is a CRC calculation SW.

Best regards

Erwan

[PLEE.2]

hello.

thanks for your answer.

i already used SPC58ECxx_RLA CRC Test Application for Discovery.(the same SPC560Pxx OS-less....)

Firmware has already applied the above code to create the CRC.

i should compare the two by making CRC in the window program with the same image.

I'm inquiring because these two crc values are different.

best regards.

Pil

[Tesla DeLorean]

For left shifting you'd need to get the data into the high order bits, surely?

CRC = ((uint)(ch) << 24) ^ CRC;

CRC are very sensitive to exact bit order, byte ordering, shift direction, etc.

If you've got anything wrong, you'll get different numbers, so pay particular attention to the details.