Intel MCS48 User Manual page 315

8255A/8255A-5
MODE
Port Definition
A
B
GROUP A GROUP
D
4
D
3
Dl
DO
PORTA
PORT C
(UPPER)
#
PORTB
PORTC
(LOWER)
OUTPUT OUTPUT
OUTPUT OUTPUT
1
OUTPUT
OUTPUT
1
OUTPUT
INPUT
1
OUTPUT OUTPUT
2
INPUT
OUTPUT
1 1
OUTPUT OUTPUT
3
INPUT INPUT
1
OUTPUT
INPUT
4
OUTPUT
OUTPUT
1 1
OUTPUT
INPUT
5
OUTPUT
INPUT
1 1
OUTPUT
INPUT
6
INPUT
OUTPUT
1 1
1
OUTPUT
INPUT
7
INPUT INPUT
INPUT
OUTPUT
8
OUTPUT OUTPUT
1
INPUT
OUTPUT
9
OUTPUT
INPUT
1
INPUT
OUTPUT
10
INPUT
OUTPUT
1 1
INPUT OUTPUT
11
INPUT
INPUT
1
INPUT INPUT
12
OUTPUT
OUTPUT
1
1
INPUT
INPUT
13
OUTPUT
INPUT
1
1
INPUT INPUT
14
INPUT
OUTPUT
1
1 1
INPUT INPUT
15
INPUT INPUT
MODE
Configurations
CONTROL WORD
#0
°7
D
6
D
5
D
4
D
3
D
2
D
1
D
CONTROL
WORD
#1
yi
»
PA
7
-PA„
7^
PC
7
-PC
4
-A
—
pc,-pc
/
PB
7
PB
/
*
PA
7
-PAo
/^
-PCj-PC,
CONTROL
WORD
#2
1
CONTROL WORD
#3
8-25
00744A