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4-9 KEYBOARD CIRCUIT
Keyboard scan is performed by CPU interrupt routine.
P10 through P17 are commonly used with scan signal. P43 through P47 are return line of Keyboard
Matrix.
It is consist of matrix of Strobe line(8)×Return line(5) and total of 37 keys are assigned.
In order to remove chattering, key entry is confirmed when two sequential entry of a key.
P50 is used for Mode lock switch, Feed key.
Circuit Diagram
Dial Switch Board
52
ECR7100 Service Manual
Y110910 - 8
1
2
3
4
5
6
7
DC1
2mm Pitch Board-in
OFF
REG1
REG2
X
Z
PRG
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
CN2
2mm Pitch Board-in
DS1
12
11
10
9
8
7
6
5
4
3
2
1
1
2
3
4
5
6
7
CN1
2mm Pitch Board-in
SW1
00
SW10
01
SW18
02
SW26
03
SW2
10
SW11
11
SW19
12
SW27
13
SW3
20
SW12
21
SW20
22
SW28
23
SW4
30
SW13
31
SW21
32
SW29
33
SW5
40
SW14
41
SW22
42
SW9
75
SW6
50
SW15
51
SW23
52
SW30
53
SW7
60
SW16
61
SW24
62
SW31
63
SW8
70
SW17
71
SW25
72
SW32
73
SW34
44
SW35
54
SW36
64
SW37
74
SW33
04
SCAN0
SCAN1
SCAN2
SCAN3
SCAN4
SCAN5
SCAN6
SCAN7
RETURN0
RETURN1
RETURN2
RETURN3
RETURN4
RETURN5
RETURN0
RETURN1
RETURN2
RETURN3
RETURN4
RETURN5
MDRTN
SCAN0
SCAN1
SCAN2
SCAN3
SCAN4
SCAN5
SC
AN7
SC
AN7
SC
AN6
SC
AN5
SC
AN4
SC
AN3
SC
AN2
SC
AN1
SC
AN0
MDRTN
COM
D1
1N4148
D2
1N4148
D3
1N4148
D4
1N4148
D5
1N4148
D6
1N4148
D7
1N4148
D8
1N4148
D9
1N4148
S0
S1
S2
S3
S4
S5
S6
S7
S7
F
A
K
D1-D9
1N4148
A
K
D1-D9
1N4148
ECR6700
ECR6100
Diode Direction