Abov MC96F6432Q - P4 Port

MC96F6432
June 22, 2018 Ver. 2.9 81
9.7 P4 Port
9.7.1 P4 Port Description
P4 is 4-bit I/O port. P4 control registers consist of P4 data register (P4), P4 direction register (P4IO), P4 pull-up
resistor selection register (P4PU) and P4 open-drain selection register (P4OD). Refer to the port function
selection registers for the P4 function selection.
9.7.2 Register description for P4
P4 (P4 Data Register) : A0H
7
6
5
4
3
2
1
0
–
–
–
–
P43
P42
P41
P40
–
–
–
–
R/W
R/W
R/W
R/W
Initial value : 00H
P4[3:0]
I/O Data
Note) Do not use the “direct bit test and branch” instruction for input port, more detail information is at
Appendix B.
Example) Avoid direct input port bit test and branch condition as below
If(P40) → if(P4 & 0x01)
P4IO (P4 Direction Register) : C9H
7
6
5
4
3
2
1
0
–
–
–
–
P43IO
P42IO
P41IO
P40IO
–
–
–
–
R/W
R/W
R/W
R/W
Initial value : 00H
P4IO[3:0]
P4 Data I/O Direction
0
Input
1
Output
NOTE: SS0 function possible when input