
5. I/O ports
MC97F6108A User’s manual
42
5.3
P1 port
5.3.1
P1 port description
P1 is an 8-bit I/O port. P1 control registers consist of P1 data register (P1), P1 direction register (P1IO),
debounce enable register (P15DB), P1 pull-up resistor selection register (P1PU), and P1 open-drain
selection register (P1OD). Refer to the port function selection registers for the P1 function selection.
5.3.2
Register description for P1
P1 (P1 Data Register): 88H
7
6
5
4
3
2
1
0
P17
P16
P15
P14
P13
P12
P11
P10
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value: 00H
P1[7:0]
I/O Data
P1IO (P1 Direction Register): 91H
7
6
5
4
3
2
1
0
P17IO
P16IO
P15IO
P14IO
P13IO
P12IO
P11IO
P10IO
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value: 00H
P1IO[7:0]
P1 Data I/O Direction
0
Input
1
Output
P1PU (P1 Pull-up Resistor Selection Register): 2F08H
7
6
5
4
3
2
1
0
P17PU
P16PU
P15PU
P14PU
P13PU
P12PU
P11PU
P10PU
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value: 00H
P1PU[7:0]
Configure Pull-up Resistor of P1 Port
0
Disable
1
Enable
P1OD (P1 Open-drain Selection Register): 2F09H
7
6
5
4
3
2
1
0
P17OD
P16OD
P15OD
P14OD
P13OD
P12OD
P11OD
P10OD
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value: 00H
P1OD[7:0]
Configure Open-drain of P1 Port
0
Push-pull output
1
Open-drain output