User's Manual

Chapter 4 Register-Level Programming

Analog Input Register Group

The four registers making up the Analog Input Register Group control the analog input circuitry

and are used for reading from the A/D FIFO. The A/D Configuration Register selects the input

channel to be read, the gain for that channel, and some information about the input data. The

Status Register reports the status of the current A/D conversion and returns any errors found.

Reading the A/D FIFO Register returns stored A/D conversion results. Writing to this register

resets the error bits in the Status Register and empties the A/D FIFO. One garbage data byte is

stored in the FIFO as a result of the clear operation, so the FIFO must be read after an A/D clear

to remove this data byte before starting a new conversion.

Bit descriptions for the registers in the Analog Input Register Group are given on the following

pages.