5. I/O ports
MC97F6108A User’s manual
38
5.2
P0 port
5.2.1
P0 port description
P0 is an 8-bit I/O port. P0 control registers consist of P0 data register (P0), P0 direction register (P0IO),
debounce enable register (P0DB), P0 pull-up resistor selection register (P0PU), and P0 open-drain
selection register (P0OD). Refer to the port function selection registers for the P0 function selection.
5.2.2
Register description for P0
P0 (P0 Data Register): 80H
7
6
5
4
3
2
1
0
P07
P06
P05
P04
P03
P02
P01
P00
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value: 00H
P0[7:0]
I/O Data
P0IO (P0 Direction Register): 89H
7
6
5
4
3
2
1
0
P07IO
P06IO
P05IO
P04IO
P03IO
P02IO
P01IO
P00IO
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value: 00H
P0IO[7:0]
P0 Data I/O Direction.
0
Input
1
Output
P0PU (P0 Pull-up Resistor Selection Register): 2F00H
7
6
5
4
3
2
1
0
P07PU
P06PU
P05PU
P04PU
P03PU
P02PU
P01PU
P00PU
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value: 20H
P0PU[7:0]
Configure Pull-up Resistor of P0 Port
0
Disable
1
Enable
P0OD (P0 Open-drain Selection Register): 2F01H
7
6
5
4
3
2
1
0
P07OD
P06OD
P05OD
P04OD
P03OD
P02OD
P01OD
P00OD
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value: 00H
P0OD[7:0]
Configure Open-drain of P0 Port
0
Push-pull output
1
Open-drain output
