Epson PX-8 - Page 281

REV.-A
7508 (Sub-CPU)
1 . Location:
MAPLE Board, 2E
2. Pin
Assignments
x 2
40 X I
P2vPST8 2
39
Vss
P2o/PTOUT
3 38 P43
P22 4 37
P42
P23 5
36
P41
Pia 6 35 P40
PII
7
34
PS3
P 12 8 33 PS2
P
13
9 32 PSI
P30 10
31
Pso
P 31 II 30 P63
P32
12 29
PS2
P33 13 28 PSI
P70 14
27 Pso
P 71
15 26 P03/S1
Pn
16 25 P02/S0
P 73
17 24
POI/SCK
RESET
18
23 Poo /INTO
CLI 19
22
INTI
Voo
20 21 CL2
Table 7-4 7508 SUB-CPU Pin Assignments
Pin No.
Signal Name
In/Out
Function
1
x2
In
Unused.
2
P20
Out
GAH40M SIOR access control- H:
7508, L:
Main CPU
3
P21
Out
A-D converter 7001 Chip Select - mode
switching between address data and A-D
conversion.
4
P22 Out
Ready signal
5 P23 Out
A-D converter 7001 power on/off
6
P10 In
Key return 0
7
P11 In
Key return 1
8 P12
In
Key return 2
9 P13
In
Key return 3
10 P30 Out
Key scan control
11
P31 Out
Key scan control
12 P32
Out
Key scan control
13
P33
Out Key scan control
14 P70 Out Power ON/OFF
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