![](http://datasheet.mmic.net.cn/280000/HD6435348R_datasheet_16065040/HD6435348R_176.png)
9.6 Port 5
9.6.1 Overview
Port 5 is an 8-bit input/output port with the pin configuration shown in figure 9-11. In the
expanded modes that use the on-chip ROM (modes 2 and 4), the pins of port 5 function either as
general-purpose input pins or as bits A
15
– A
8
of the address bus, depending on the port 5 data
direction register (P5DDR).
Port 5 has built-in MOS pull-ups that can be turned on or off under program control.
Outputs from port 5 can drive one TTL load and a 90 pF capacitive load. They can also drive a
Darlington transistor pair.
P4
7
(input/output)
P4
6
(input/output)
P4
5
(input/output)
P4
4
(input/output)
P4
3
(input/output)
P4
2
(input/output)
P4
1
(input/output)
P4
0
(input/output)
Port
4
Pin
P5
7
/ A
15
P5
6
/ A
14
P5
5
/ A
13
P5
4
/ A
12
P5
3
/ A
11
P5
2
/ A
10
P5
1
/ A
9
P5
0
/ A
8
Modes 1 and 3
A
15
(output)
A
14
(output)
A
13
(output)
A
12
(output)
A
11
(output)
A
10
(output)
A
9
(output)
A
8
(output)
Modes 2 and 4
P5
7
(input) / A
15
(output)
P5
6
(input) / A
14
(output)
P5
5
(input) / A
13
(output)
P5
4
(input) / A
12
(output)
P5
3
(input) / A
11
(output)
P5
2
(input) / A
10
(output)
P5
1
(input) / A
9
(output)
P5
0
(input) / A
8
(output)
Single-Chip Mode
P5
7
(input/output)
P5
6
(input/output)
P5
5
(input/output)
P5
4
(input/output)
P5
3
(input/output)
P5
2
(input/output)
P5
1
(input/output)
P5
0
(input/output)
Port
5
Figure 9-10 Port 4 Pin Functions in Single-Chip Mode
Figure 9-11 Pin Functions of Port 5
159