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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 7-4.
The pin functions differ depending on the operating mode. In mode 1, settings in the port 1 data
direction register (P1DDR) can designate pins for address bus output (A
In modes 2 and 3, port 2 is a generic input/output port.
Port 2 has software-programmable built-in pull-up transistors. Pins in port 2 can drive one TTL
load and a 90-pF capacitive load. They can also drive a darlington transistor pair.
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Port 2 pins
P2 /A
7
15
P2 /A
6
14
P2 /A
5
13
P2 /A
4
12
Port 2
P2 /A
3
11
P2 /A
2
10
P2 /A
1
9
P2 /A
0
8
Figure 7-4 Port 2 Pin Configuration
15
Mode 1
Modes 2 and 3
P2 (input)/A
(output)
P2 (input/output)
7
15
P2 (input)/A
(output)
P2 (input/output)
6
14
P2 (input)/A
(output)
P2 (input/output)
5
13
P2 (input)/A
(output)
P2 (input/output)
4
12
P2 (input)/A
(output)
P2 (input/output)
3
11
P2 (input)/A
(output)
P2 (input/output)
2
10
P2 (input)/A
(output)
P2 (input/output)
1
9
P2 (input)/A
(output)
P2 (input/output)
0
8
126
to A
) or generic input.
8
7
6
5
4
3
2
1
0
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