The Microcontroller Idea Book - Jan Axelson's Lakeview Research

Chapter 6
Table 6-2. Pin functions for the 8255 Programmable Peripheral Interface.
Pin Symbol Input/
Output
Function
1 PA3 I/O Port A, bit 3
2 PA2 I/O Port A, bit 2
3 PA1 I/O Port A, bit 1
4 PA0 I/O Port A, bit 0
5 RD I Read
6 CS I Chip select
7 GND I Signal ground
8 A1 I Port select 1
9 A0 I Port select 0
10 PC7
OBFA
11 PC6
ACKA
12 PC5
IBFA
13 PC4
STBA
14 PC0
INTRB
15 PC1
IBFB
OBFB
16 PC2
STBB
ACKB
17 PC3
INTRA
I/O
O
I/O
I
I/O
O
I/O
I
I/O
O
I/O
O
O
I/O
I
I
I/O
O
Port C, bit 7
Port A output buffer full
Port C, bit 6
Port A acknowledge
Port C, bit 5
Port A input buffer full
Port C, bit 4
Port A strobe
Port C, bit 0
Port B interrupt request
Port C, bit 1
Port B input buffer full
Port B output buffer full
Port C, bit 2
Port B strobe
Port B acknowledge
Port C, bit 3
Port A interrupt request
18 PB0 I/O Port B, bit 0
19 PB1 I/O Port B, bit 1
20 PB2 I/O Port B, bit 2
100 The Microcontroller Idea Book