AURIX™ Forum Discussions

[User17092]

Hi Support team,
On DAP module TSv2.3, CRC-6 algorithm is not correct on section 1.8.3. We cannot get correct CRC value for transmitting packets. The result of function GetCrc cannot pass CRC Check at all.

Does anyone report similar issue?
Thanks!

[User17092]

Here are the codes from the document:

const unsigned crc6Polynom =0x03; // x**6 + x + 1
unsigned CalcCrc(unsigned crcValue, unsigned thisbit) {
unsigned m = crcValue & crc6Polynom;
while (m > 0) {
thisbit ^= (m & 1);
m >>= 1;
}
return (((thisbit << 6) | crcValue) >> 1);
}
// obtain CRC6 for sending (6 bit)
unsigned GetCrc(unsigned crcValue) {
unsigned crc6 = 0; int i;
for (i = 0; i < 6; i++) {
crcValue = CalcCrc(crcValue, 0);
crc6 |= (crcValue & 0x20) | (crc6 >> 1);
crcValue &= 0x1F; // remove output bit
}
return (crc6);
}
// Calculate CRC6
for (i = 1; i < nDataBits; i++) { // Startbit excluded
thisBit = (unsigned)((telegram >> i) & 0x1);
crcValue = CalcCrc(crcValue, thisBit);
}
/* now send telegram + GetCrc(crcValue) */

// Check CRC6
unsigned crcValue = 0x3f;
int i;
unsigned thisBit;
for(i=1; i thisBit = (unsigned)((telegram>>i)&0x1);
crcValue = CalcCrc(crcValue, thisBit);
}
if(crcValue!=0) { /* put error handler here */ }


This is not the standard CRC6 algorithm. The issue is function GecCrc.

[User17092]

Got this issue solved. The CRC algorithm on document is TOTALLY wrong.

[User17829]

Hi Robinliuy,

may I ask you to share how you could solve this problem ?

I'm currently facing same issue. Impossible to pass the CRC6 check. I got the same C-Like code in my reference document.

Thanks in advance.
Best regards.

[StanWang]

Dear sir,

i am also intersted in DAP.

could you please tell me where could find DAP module TSv2.3 ?

i could not search it from website.

thank you.