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7.3
Port 2
7.3.1
Overview
Port 2 is an 8-bit input/output port with the pin configuration shown in figure 7.5. The pin
functions differ depending on the operating mode.
Port 2 has built-in, software-controllable MOS input pull-up transistors that can be used in modes
2 and 3.
Pins in port 2 can drive one TTL load and a 90-pF capacitive load. They can also drive LEDs and
darlington transistors.
P2
7
/A
15
P2
6
/A
14
P2
5
/A
13
P2
4
/A
12
P2
3
/A
11
P2
2
/A
10
P2
1
/A
9
P2
0
/A
8
Port 2
Port 2 pins
A
15
(output)
A
14
(output)
A
13
(output)
A
12
(output)
A
11
(output)
A
10
(output)
A
9
(output)
A
8
(output)
Pin configuration
in mode 1
(expanded mode
with on-chip ROM
disabled)
A
15
(output)/P2
7
(input)
A
14
(output)/P2
6
(input)
A
13
(output)/P2
5
(input)
A
12
(output)/P2
4
(input)
A
11
(output)/P2
3
(input)
A
10
(output)/P2
2
(input)
A
9
(output)/P2
1
(input)
A
8
(output)/P2
0
(input)
Pin configuration
in mode 2
(expanded mode
with on-chip ROM
enabled)
P2
7
(input/output)
P2
6
(input/output)
P2
5
(input/output)
P2
4
(input/output)
P2
3
(input/output)
P2
2
(input/output)
P2
1
(input/output)
P2
0
(input/output)
Pin configuration in mode 3
(single-chip mode)
Figure 7.5 Port 2 Pin Configuration