Z86D990 Datasheet, PDF (77/102 Pages) Zilog, Inc. – Low-Voltage Micro controllers with ADC

Z86D990/Z86D991 OTP and Z86L99X ROM
Low-Voltage Microcontrollers with ADC
70
Port 5 Control and Mode Registers (P5 and P5M)
Port 5 is a general-purpose 8-bit, bidirectional I/O port, as shown in Table 30.
Each of the eight Port 5 I/O lines can be independently programmed as either
input or output using the Port 5 Mode Register (see Table 31.)
Table 30. P5 Register [Group/Bank 00h, Register 5 (R5)]
Bit
7
6
5
4
Bit/Field Port 5 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 5 Data
R/W Data
3
2
1
0
R/W R/W R/W R/W
X
X
X
X
Description
Port 5 Input/Output Register
Table 31. P5M Register (Group/Bank 0Fh, Register 4)
Bit
7
6
5
4
Bit/Field P57M P56M P55M P54M
R/W
R/W R/W R/W R/W
Reset
1
1
1
1
R = Read, W = Write, X = Indeterminate
Bit
Position
Bit/Field
R/W Value
7654__10 Port 5 Mode
(by bit)
Select
R/W 1
0
____32__ P53, P52
Mode Select
R/W 1
3
P53M
R/W
1
2
P52M
R/W
1
1
P51M
R/W
1
0
P50M
R/W
1
Description
Input
Output
Input
Regardless of what is written to this
pin, P53 and P52 are always in input
mode.
A bit set to a 1 in the P5M Register configures the corresponding bit in Port 5 as
an input, while a bit set to 0 configures an output line.
Note: Regardless of how P5M bits 2 and 3 are set, P52 and P53 are
always in input mode.
PS003807-1002
PRELIMINARY