In checksum mode, the checksum byte is the lower 8-bit sum of the data conversion bytes plus an offset value 9Bh. The offset value is added to help detect whether the DOUT/DRDY has failed and is in a permanent low state. ADC1 sums four data bytes. and ADC2 sums three data bytes. To verify the correct checksum, sum the data bytes plus 9Bh and compare the value read from the ADC. If the checksum values do not match, a data transmission error occurred. In the event of a data transmission error, read the data again for verification. The checksum provides basic levels of error detection caused by single-bit errors, and limited combinations of multiple-bit errors.
Example computation of ADC1 four-data-byte checksum calculation: