Z90251 Datasheet, PDF (66/97 Pages) Zilog, Inc. – eZVision 200 Television Controllers with OSD

Z90255 ROM and Z90251 OTP
32 KB Television Controller with OSD
58
Table 40 Port 2 Mode Register F6h: P2M
Bit
7
6
5
4
3
2
1
0
R/W
W
W
W
W
W
W
W
W
Reset
1
1
1
1
1
1
1
1
Note: R = Read W = Write X = Indeterminate
Bit/
Field
Bit
Position
R/W Value Description
P27 I/O Definition
7
W
0 Defines P27 as Output
1 Defines P27 as Input
P26 I/O Definition
6
W
0 Defines P26 as Output
1 Defines P26 as Input
P25 I/O Definition
5
W
0 Defines P25 as Output
1 Defines P25 as Input
P24 I/O Definition
4
W
0 Defines P24 as Output
1 Defines P24 as Input
P23 I/O Definition
3
W
0 Defines P23 as Output
1 Defines P23 as Input
P22 I/O Definition
2
W
0 Defines P22 as Output
1 Defines P22 as Input
P21 I/O Definition
1
W
0 Defines P21 as Output
1 Defines P21 as Input
P20 I/O Definition
0
W
0 Defines P20 as Output
1 Defines P20 as Input
When P27/P26 or P25/P24 are used as I²C pins, then these pins are
automatically set to open-drain mode.
Table 41 Port 2 Data Register 02h: P2
Bit
7
6
5
R/W
R/W R/W R/W
Reset
x
x
x
Note: R = Read W = Write X = Indeterminate
4
R/W
x
3
R/W
x
2
R/W
x
1
0
R/W R/W
x
x
PS001301-0800