Computing the CRC8-ATM CRC in Python

The 8-bit CRC8-ATM polynomial is used in many embedded applications, including Trinamic UART-controlled stepper motor drivers like the TMC2209:

The following code provides an example on how to compute this type of CRC in Python:

def compute_crc8_atm(datagram, initial_value=0):
    crc = initial_value
    # Iterate bytes in data
    for byte in datagram:
        # Iterate bits in byte
        for _ in range(0, 8):
            if (crc >> 7) ^ (byte & 0x01):
                crc = ((crc << 1) ^ 0x07) & 0xFF
            else:
                crc = (crc << 1) & 0xFF
            # Shift to next bit
            byte = byte >> 1
    return crc

This code has been field-verified for the TMC2209.