S32 Design StudioのトピックRe: S32DS CRC 8 calculation

S32DS CRC 8 calculation

satish_k_singh — Mon, 06 May 2019 14:24:23 GMT

Hello,

Currently I am working with the S32DS on the S32K148 EVAL board . The MCU has in built hard ware accelerator to calculate the CRC which is 32bits and 16 bits respectively.

Could you please let know how can I make use of the same to calculate 8 bit CRC with given seed and polynomial.

Thanks and best regards!!!

Satish Kumar

Re: S32DS CRC 8 calculation

lukaszadrapa — Tue, 07 May 2019 07:59:54 GMT

Hi,

because this is not supported by hardware CRC module, the only way is to use SW calculation.

You can find some SW examples on the web. First one I found on google:

c - Calculating a simple CRC - Electrical Engineering Stack Exchange

Hope this helps.

Regards,

Lukas

Re: S32DS CRC 8 calculation

tim_povall — Thu, 07 May 2020 21:22:55 GMT

I am a year late to this question, but 8-bit CRC actually is possible with a 16 or 32-bit CRC module.

You can convert the 8-bit polynomial into 16-bit by shifting 8 bits to the left, and then to get a 8-bit result do the same to the resulting 16-bit CRC.

For example, lets say I want to do CRC on the following ascii: '123456789', and my polynomial is 0xD5 (binary: 1101 0101). My resulting 8-bit CRC, with a seed value of 0x00, should be 0xBC (binary 1011 1100‬).

I am using a Freedom KEAZ64 board, which has a 16-bit CRC module. I shift my polynomial 8-bits to the left, which gives me 0xD500 (binary: 1101 0101 0000 0000). On the same ascii data, the 16-bit CRC outputs 0xBC00 (binary 1011 1100 0000 0000), so all we need to do is shift the result 8 bits to the right to get the correct result: 0xBC

I hope this is useful for anyone who happens to find this question,

Tim