AM2634-Q1: CRC-16/IBM-3740 Calculation Using MCRC Module on TI AM2634 Controller

Hi Rahul,

Thanks for reaching out. This should be possible, but it isn't clear to me how this would be handled from a software perspective. I am looping in a fellow expert to provide additional feedback for application level usage of the MCRC.

In the meantime, please refer to the thread below where similar functionality was implemented via MCAL MCRC.

(+) AM2634: Doubts regarding mcrc module - Arm-based microcontrollers forum - Arm-based microcontrollers - TI E2E support forums

Best Regards,

Zackary Fleenor

Hi Zackary,

From a software perspective, I am referring to implementing CRC using C code in the application.

For ex -

uint16_t crc16_ibm3740(const uint8_t *data, size_t length) {
    uint16_t crc = CRC16_IBM3740_INIT;
    int i, j;
    
    for (i = 0; i < length; i++) {
        crc ^= (uint16_t)(data[i] << 8);
        for (j = 0; j < 8; j++) {
            if (crc & 0x8000) {
                crc = (crc << 1) ^ CRC16_IBM3740_POLY;
            } else {
                crc = crc << 1;
            }
        }
    }
    
    return crc;
}

Thanks,
Rahul

Hi Rahul,

Rahul Dahiya said:

Polynomial: 0x1021
Initial value: 0xFFFF
Input reflection: False
Result reflection: False
Final XOR value: 0x0000

Our CRC-16 polynomial is matching with yours.

Please test it at your end with our MCRC-16 polynomial once. Regarding, initial value, input reflection and output reflection even if they didn't match, we can do some software workaround on top of the MCRC module. If you want default values of these parameters in MCRC, then i will test and let you know.

--
Thanks & regards,
Jagadish.

Hi Jagdish,

Using the settings mentioned below, I am getting a CRC16-XMODEM result. When I pass the data 0xAAAAAAAA, the output I get is 0x1E95, which corresponds to CRC16-XMODEM. Could you please let me know what settings I should use for CRC-IBM3740?

static SDL_MCRC_Config_t SDL_MCRC_Config =
{
     SDL_MCRC_CTRL0_CH1_CRC_SEL_16BIT,
     SDL_MCRC_DATALENGTH_16BIT,
     SDL_MCRC_DATA_16_BIT,
     SDL_MCRC_BITSWAP_MSB,
     SDL_MCRC_BYTESWAP_DISABLE
};

Thanks,
Rahul

Hi Rahul,

I am off for a week due to personal work, so i didn't get time to look into this issue.

Are you still stuck with this issue?

--
Thanks & regards,
Jagadish.