ZILOG
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Z80 PIO USER=S MANUAL
20
D3 D4
10
39
9
38 3
D5 D6
8 7
2
D7
Z80-PIO 18
6
Port A/B SEL
16
5
Control/Data SEL PIO Control
13 12
1 40
D2 CPU Data Bus
15 14
19
D0 D1
27
4 37
/Chip Enable /M1
36
/IORQ
11
GND
A5 A7 ARDY /ASTB B0 B2
34
B3 B4 B5 B6 B7
25
/INT Interrupt Control
21 17
23
BRDY /BSTB
24 22
INT Enable In INT Enable Out
Figure 3-1. PIO Pin Functions
6 B//A
7
PA7
8
PA6
9
PA5
10
PA4
11
N/C
12
GND
13
PA3
14
PA2
15
PA1
16
PA0
5
4
3
2
1
44
43
42
41
40
Z80-PIO
17 18
19
20
21
22 23
24
25
26
27
39
/RD
38
PB7
37
PB6
36
PB5
35
PB4
34
PB3
33
PB2
32
PB1
31
PB0
30
+5V
29
CLK
28
Figure 3-2. PIO 44-Pin PLCC Pin Assignments
Port A I/O
A6
B1
32 33
26
A3 A4
29 31
+5V
A2
28 30
35
/RD
A0 A1
Port B I/O