Z86L972 Datasheet, PDF (68/91 Pages) Zilog, Inc. – Low-Voltage Microcontrollers

Z86L972/Z86L973/Z86L974
Low-Voltage Microcontrollers
61
Table 23. P3M Register [Group/Bank F0h, Register 7 (R247)]
Bit
7
6
5
4
3
2
1
Bit/Field Reserved
R/W
W
W
W
Reset
1
1
1
R = Read, W = Write, X = Indeterminate
Bit
Position Bit/Field
R/W
7654321_ Reserved
R
W
_________0 Port 2 Output W
Configuration
W
1
Value
1
X
1
0
W
W
W
1
1
1
Description
Always reads 1111111
No Effect
Push-Pull Active
Open Drain Outputs
0
P2_
Output
W
1
Port 2 Control and Mode Registers (P2 and P2M)
Port 2 is a general-purpose 8-bit, bidirectional I/O port, as shown in Table 24.
Each of the eight Port 2 I/O lines can be independently programmed as either
input or output using the Port 2 Mode Register (see Table 25.)
Table 24. P2 Register [Group/Bank 00h, Register 2 (R2)]
Bit
7
6
5
4
Bit/Field Port 2 Data
R/W
R/W R/W R/W R/W
Reset
X
X
X
X
R = Read, W = Write, X = Indeterminate
Bit
Position
Bit/Field
R/W Value
76543210 Port 2 Data
R/W Data
3
2
1
0
R/W R/W R/W R/W
X
X
X
X
Description
Port 2 Input/Output Register
Table 25. P2M Register [Group/Bank F0h, Register 6 (R246)]
Bit
7
6
5
4
Bit/Field P27M P26M P25M P24M
R/W
W
W
W
W
Reset
1
1
1
1
R = Read, W = Write, X = Indeterminate
Bit
Position
Bit/Field
R/W Value
76543210 Port 2 Mode
R
1
(by bit)
Select
W
1
W
0
3
P23M
W
1
2
P22M
W
1
1
P21M
W
1
Description
Always reads 11111111
Input
Output
0
P20M
W
1
PS010504-1002
PRELIMINARY