A cyclic redundancy check (CRC) is enabled by setting the CRC bit to 1 in the system control register (10h). When CRC mode is enabled, the 8-bit CRC is appended to the conversion result. The CRC is calculated for the 24-bit conversion result and the STATUS byte when enabled.
In CRC mode, the checksum byte is the 8-bit remainder of the bitwise exclusive-OR (XOR) of the data bytes by a CRC polynomial. For conversion data, use three data bytes. The CRC is based on the CRC-8-ATM (HEC) polynomial: X8 + X2 + X + 1.
The nine binary coefficients of the polynomial are: 100000111. To calculate the CRC, divide (XOR operation) the data bytes (excluding the CRC) with the polynomial and compare the calculated CRC values to the ADC CRC value. If the values do not match, a data transmission error has occurred. In the event of a data transmission error, read the data again.
The following list shows a general procedure to compute the CRC value: