Z90251 Datasheet, PDF (69/97 Pages) Zilog, Inc. – eZVision 200 Television Controllers with OSD

Z90255 ROM and Z90251 OTP
32 KB Television Controller with OSD
61
Bit/
Field
P42
P41
P40
Bit
Position
2
1
0
R/W Value
R
W
R
W
R
W
Description
Data input on P42
Data Output on P42
Data input on P41
Data Output on P41
Data input on P40
Data Output on P40
Table 44 Port 4 Direction Control Register 06h: Bank C (PRT4_DRT)
Bit
7
6
5
R/W
Reset
R/W R/W R/W
1
1
1
Note: R = Read W = Write X = Indeterminate
4
R/W
1
3
R/W
1
2
R/W
1
1
R/W
1
0
R/W
1
Bit/
Field
P47 I/O Definition
P46 I/O Definition
P45 I/O Definition
P44 I/O Definition
P43 I/O Definition
P42 I/O Definition
P41 I/O Definition
P40 I/O Definition
Bit
Position
7
6
5
4
3
2
1
0
R/W Value Description
R/W
0 Defines P47 as Output
1 Defines P47 as Input-POR
R/W
0 Defines P46 as Output
1 Defines P46 as Input-POR
R/W
0 Defines P45 as Output
1 Defines P45 as Input-POR
R/W
0 Defines P44 as Output
1 Defines P44 as Input-POR
R/W
0 Defines P43 as Output
1 Defines P43 as Input-POR
R/W
0 Defines P42 as Output
1 Defines P42 as Input-POR
R/W
0 Defines P41 as Output
1 Defines P41 as Input-POR
R/W
0 Defines P40 as Output
1 Defines P40 as Input-POR
PS001301-0800