Z90251 ZILOG [Zilog, Inc.], Z90251 Datasheet - Page 67

• Manufacturer Part Number: Z90251
• Description: eZVision 200 Television Controllers with OSD
• Manufacturer: ZILOG [Zilog, Inc.]

7.1
Port 4 Pin-Out Selection Register
Bits 5,4,3, and 2 control the configuration of multiplexed pins 20, 19, 18, and
17. If a bit is set to 0, the pin functions as a PWM output port. If a bit is set to 1, the
pin functions as a programmable regular input/output port. See Table 42. This
value is the default following a Power-On Reset.
Table 42 Port 4 Pin-Out Selection Register 08h: Bank C (PIN_SLT)
Bit/
Field
P27
P26
P25
P24
P23
P22
P21
P20
Bit
R/W
Reset
Note: R = Read W = Write X = Indeterminate
Bit
Position
7
6
5
4
3
2
1
0
7
R/W
x
6
R/W
x
R/W
W
W
W
W
W
W
W
W
R
R
R
R
R
R
R
R
5
R/W
1
Value
4
32 KB Television Controller with OSD
R/W
1
Description
Data input on P27
Data Output on P27
Data input on P26
Data Output on P26
Data input on P25
Data Output on P25
Data input on P24
Data Output on P24
Data input on P23
Data Output on P23
Data input on P22
Data Output on P22
Data input on P21
Data Output on P21
Data input on P20
Data Output on P20
3
R/W
1
2
R/W
1
1
R/W
PS001301-0800
x
0
R/W
x
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