User`s guide

Elan Digital Systems Ltd. 26 AD125 USER’S GUIDE
3.5.6 DIGITAL IO
There are 8 digital IO lines which can be used for general control /
monitoring.
The bottom 4 bits of the IODIR register are used to configure the
IOPINs as inputs or outputs. The grouping is as follows:
BIT0 DIRECTION OF IOPIN1
BIT1 DIRECTION OF IOPIN2
BIT2 DIRECTION OF IOPIN3&4
BIT3 DIRECTION OF IOPIN5,6,7&8.
Setting a bit high enables the pin/group of pins as outputs. The data to
/ from the pins is read via the IODATA register as an 8-bit byte and
logically the bit position in the byte corresponds to the particular
IOPIN that is addressed i.e. Bit 4 ⇔ IOPIN4.
Please read the section on Operational Precautions for tips on how
to protect the digital IO pins if they are to be subjected to active
power while the AD125 itself is unpowered.