User`s manual

D0D1D2D3D4D5D6D7
01324567
DIO PORT B DATA
BADR3 + 5
PORT B can be configured as an 8-bit input or output channel. Functionality is the same as PORT A.
READ/WRITE
D0D1D2D3D4D5D6D7
01324567
DIO PORT C DATA
BADR3 + 6
PORT C can be configured as an 8-bit port of either inputs or outputs, or it can be split into two independ-
ent 4-bit ports for inputs or outputs. When split into two, 4-bit I/O ports,
D[3:0]
is the lower nibble,
D[7:4]
is the upper nibble. Although it can be split, every write to Port C is a byte operation. Unwanted
information must be ANDed out during reads and writes must be ORd with current value of the other 4-bit
port.
READ/WRITE
D0D1D2D3D4D5D6D7
01324567
DIO CONTROL REGISTER
BADR3 + 7
The DIO Control register is used configure Ports A, B, and C as inputs or outputs. Operation is 8255, in
Mode 0.
WRITE
D0D1D2D3D4D5D6D7
01324567
The following table summarizes the possible DI/O Port configurations.
32