MC81F4x16
R4CONL – R40~R43
R4 PORT CONTROL LOW REGISTER
00DFH
A reset clears the R4CONL register to „AAH‟, makes the R43-R40 pins to open drain output mode.
You can use R4CONL register setting to select input (with or without pull-up) or output mode (open-
drain or push-pull) .
7
6
5
4
3
2
1
0
R43
R42
R41
R40
R4CONL
Reset value: AAH
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
00: Input mode
01: Input pull-up mode
R43
R42
R41
R43
10: Output mode, open-drain
11: Output mode, push-pull
00: Input mode
01: Input pull-up mode
10: Output mode, open-drain
11: Output mode, push-pull
00: Input mode
R42
R41
R40
01: Input pull-up mode
10: Output mode, open-drain
11: Output mode, push-pull
00: Input mode
01: Input pull-up mode
10: Output mode, open-drain
11: Output mode, push-pull
R40
R4
R4 PORT DATA REGISTER
00C4H
7
6
5
4
3
2
1
0
R47
R46
R45
R44
R43
R42
R41
R40
R4
Reset value: FFH
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
In input mode, it represents the R4 port status.
In output mode, R4 port represents it.
1: High
0 : Low
88
October 19, 2009 Ver.1.35