The checksum is computed from the received data and compared to the checksum value transmitted by using a bitwise XOR. A checksum error occurs if a nonzero value is computed from the XOR. The checksum used for the ADS131A0x differs from the computation for the ADS1259 discussed in Section 2.1.

/**
 * Computation and verification of the checksum from the Hamming byte.
 *
 * \details Computation of checksum bits using a checksum bit mask and counting
 * the number of bits set in the masked value.
 *
 * \param    uint32_t in of the value to be computed and compared.
 *
 * \returns  uint32_t Returns 0 if a match or non-zero for a failure.
 */
uint32_t checkSum(uint32_t in)
{
    // Compute the checksum for the data after stripping out the hamming/checksum byte
    // compare the the computed checksum with the hamming/checksum byte by XORing
    // the result should be '0' for a proper checksum.  Remember to compare after moving
    // the checksum left by 1 to place the checksum in the proper position.  Also remove
    // all other bits in the compare that are not checksum by ANDing with 
    // 0x06 (0x03 shifted left by one)
    return (in ^ ((countBits(in & CHECKSUM_BIT_MASK) << 1))) & 0x06;
}