Z51F3220FNX Datasheet, PDF (72/312 Pages) Zilog, Inc. – Z8051 Series 8-Bit Microcontrollers

Z51F3220
Product Specification
9.5 P2 Port
9.5.1 P2 Port Description
P2 is 8-bit I/O port. P2 control registers consist of P2 data register (P2), P2 direction register (P2IO), P2 pull-up
resistor selection register (P2PU) and P2 open-drain selection register (P2OD). Refer to the port function
selection registers for the P2 function selection.
9.5.2 Register description for P2
P2 (P2 Data Register) : 90H
7
6
5
4
3
2
1
0
P27
P26
P25
P24
P23
P22
P21
P20
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Initial value : 00H
P2[7:0]
I/O Data
P2IO (P2 Direction Register) : B9H
7
6
5
P27IO
P26IO
P25IO
R/W
R/W
R/W
4
P24IO
R/W
3
P23IO
R/W
2
P22IO
R/W
P2IO[7:0]
P2 Data I/O Direction
0
Input
1
Output
NOTE: SS1 function possible when input
1
P21IO
R/W
0
P20IO
R/W
Initial value : 00H
P2PU (P2 Pull-up Resistor Selection Register) : AEH
7
6
5
4
P27PU
P26PU
P25PU
P24PU
R/W
R/W
R/W
R/W
3
P23PU
R/W
2
P22PU
R/W
P2PU[7:0]
Configure Pull-up Resistor of P2 Port
0
Disable
1
Enable
1
P21PU
R/W
0
P20PU
R/W
Initial value : 00H
P2OD (P2 Open-drain Selection Register) : 93H
7
6
5
4
P27OD
P26OD
P25OD
P24OD
R/W
R/W
R/W
R/W
3
P23OD
R/W
2
P22OD
R/W
P2OD[7:0]
Configure Open-drain of P2 Port
0
Push-pull output
1
Open-drain output
1
P21OD
R/W
0
P20OD
R/W
Initial value : 00H
PS029902-0212
PRELIMINARY
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