Epson PX-8 Technical Manual 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
7-10