82C55A Datasheet, PDF (8/23 Pages) Intel Corporation – CHMOS PROGRAMMABLE PERIPHERAL INTERFACE

82C55A
MODE 0 Port Definition
A
B
GROUP A
GROUP B
D₄
D₃
D₁
D₀
PORT A
PORT C
(UPPER)
PORT B
PORT C
(LOWER)
0
0
0
0
OUTPUT
OUTPUT
0
OUTPUT
OUTPUT
0
0
0
1
OUTPUT
OUTPUT
1
OUTPUT
INPUT
0
0
1
0
OUTPUT
OUTPUT
2
INPUT
OUTPUT
0
0
1
1
OUTPUT
OUTPUT
3
INPUT
INPUT
0
1
0
0
OUTPUT
INPUT
4
OUTPUT
OUTPUT
0
1
0
1
OUTPUT
INPUT
5
OUTPUT
INPUT
0
1
1
0
OUTPUT
INPUT
6
INPUT
OUTPUT
0
1
1
1
OUTPUT
INPUT
7
INPUT
INPUT
1
0
0
0
INPUT
OUTPUT
8
OUTPUT
OUTPUT
1
0
0
1
INPUT
OUTPUT
9
OUTPUT
INPUT
1
0
1
0
INPUT
OUTPUT
10
INPUT
OUTPUT
1
0
1
1
INPUT
OUTPUT
11
INPUT
INPUT
1
1
0
0
INPUT
INPUT
12
OUTPUT
OUTPUT
1
1
0
1
INPUT
INPUT
13
OUTPUT
INPUT
1
1
1
0
INPUT
INPUT
14
INPUT
OUTPUT
1
1
1
1
INPUT
INPUT
15
INPUT
INPUT
MODE 0 Configurations
231256 – 10
8