AURIX™ Forum Discussions

[User17612]

Hi,

before flashing a BMHD into AURIX, I want to be sure, that I use the correct CRC values inside BMHD. How do I calculate the CRC for a BMHD in AURIX on my PC?

Thank you.
Lucas


#8042000 12392

[User18151 · Accepted solution]

Hi,

You can use any available CRC calculator, which is capable to work with CRC-32 algorithm. A good one is the online CRC calculator at http://www.sunshine2k.de/coding/javascript/crc/crc_js.html

Just use following configuration for the CRC calculator:

Use CRC32
A polynomial of: 0x4C11DB7
Initial value: 0xFFFFFFFF
Final XOR Value: 0xFFFFFFFF (for non inverted CRC)
Final XOR Value: 0x00000000 (for inverted CRC)
Take care of the correct byte order for the CRC input data, e.g. 0xB3 0x59 0x00 0xFF 0xA0 0x00 0x00 0x00

Regards
Christine

[User20517]

I am trying to reproduce the CRC and cannot get the same value. Here is a sample in Mcal.c from infineon.
The spec says to run the CRC over the first 24 bytes (0x00 - 0x17)

const BMD_HDR Bmiheader =
{
0x80000024,
0x0360,
0xB359,
0xA0000000,
0xA000000F,
0x03CF36C8,
0xFC30C937,
0x550EEF9E,
0xAAF11061
};

If I run
800000240360B359A0000000A000000F03CF36C8FC30C937
thru a CRC-32, I get a different value = 0xAA8AA9AC.

Same with this example which also comes from infineon code:

const BMD_HDR Bmiheader =
{
0x80000020,
0x0370,
0xB359,
0x00000000,
0x00000000,
0x00000000,
0x00000000,
0x49E9B5B4,
0xB6164A4B
};
Using the parameters you described, I should get 0xBFF97B16, not 0x49E9B5B4.

Roger

[User20517]

I fixed it. I had to reverse the two 16-bit fields:
80000024B3590360A0000000A000000F03CF36C8FC30C937
which generates 0x550EEF9E which is correct.