Pin
No.
Port Part Name & Description I/O (V)
1 A18 A18 in Address bus O 1.5
2 A19 A19 in Address bus O 1.7
3 A20 A20 in Address bus O 1.3
4 NC Not connected - -
5 LED G - - -
6 LED B - - -
7 A0 A0 in address bus for LCD O 1.3
8 A1 A1 in Address bus O 0.3
9 VSS GND - -
10 A2 A2 in Address bus O 0.4
11 A3 A3 in Address bus O 0.4
12 A4 A4 in Address bus O 0.4
13 A5 A5 in Address bus O 1.3
14 A6 A6 in Address bus O 0.4
15 A7 A7 in Address bus O 0
16 A8 A8 in Address bus O 1.3
17 A9 A9 in Address bus O 0
18 A10 A10 in Address bus O 0
19 A11 A11 in Address bus O 1.5
20 A12 A12 in Address bus O 1.7
21 VCC +3.3V Power supply - 3.5
22 A13 A13 in Address bus O 1.4
23 A14 A14 in Address bus O 1.5
24 A15 A15 in Address bus O 1.7
25 SIN0 Serial data from Main CPU
or Flash writer
I 0.5
26 SOT0 Serial data to Main CPU or
Flash writer
O 1.8
27 SCK0 Serial clock for Flash
writer
I 3.5
28 NC Not connected - -
29 FRASH
RESET
Reset for Flash memory O 3.5
30 KS1 Key scan 1 O 0
31 NC Not connected - -
32 NC Not connected - -
33 AVCC +3.3V Power supply - 3.5
34 AVRH +3.3V Power supply - 3.5
35 AVSS/
AVRL
GND - -
36 TH
DETECT
Pulled up to H - 1.3
37 KS2 Key scan 2 O 0
38 KS3 Key scan 3 O 0
39 NC Not connected - -
40 VSS GND - -
41 KI5 Key-in return 5 I 0
14