The on-chip diagnostics are useful in any system, even an application where
functional safety is not important. The on-chip diagnostics allow the user to
verify the circuit connections, the blocks within the ADC such as the PGA,
reference and ADC itself can be monitored to ensure that all blocks are
functioning correctly. Since the on-chip registers can be monitored, the user
can be confident that no register changes have occurred. Finally, the serial
interface has a lot of diagnostics such as read/write checks, any invalid
read/write operations are ignored.
On other ADCs, the ADC does not ignore invalid commands which can lead
to register corruption or even the serial interface becoming asynchronous. The
AD7124-8’s diagnostics give the user confidence that only correct read/write
operations are sent/received by the AD7124-8, that on-chip registers are not
corrupted, and that conversions are invalid. Any errors for these conditions
will be indicated by the Error bits.