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4. IOC PWB circuit description
4-1. Block diagram
4-2. I/O controller
1. Pin assignment
Main
PWB
PWB
HTIO
IOTH, EVRQ, CTS
IOC CN
I/O
controller
controller
8MHz
Buzzer
circuit
circuit
BZU1
MCR
circuit
circuit
MINT1/2, MTS1/2, CKA1/2
Buzzer
Keyboard
circuit
circuit
ST0~4
KR0~11
MCR CN
ERA8MR
ER-A850: Normal key
ER-A880: Tuch key
Keyboard CN
Cleak key
Cleak key
Clerk key CN
WMF CN
CFSR
INP7
DUZ1
MTS1
N U
CKA1
MTS2
N U
CKA2
(OP EN)
INP8
INP9
HTS
STH
CLK
EVRQ
CTS
ST3
ST2
ST1
ST0
INP0
MODER
CFSR
(OPEN)
KR15
KR14
KR13
KR12
KR11
KR10
KR9
KR8
KR
24
KR
25
KR
26
AV
C
C
AV
R
AV
SS
KR
27
KR
28
KR
29
KR
30
KR
31
MO
D
X0
X1
VS
S
IO
BE
S
KR
0
KR
1
KR
2
KR
3
KR
4
KR
5
KR
6
KR
7
IN
P
6
IN
P
5
IN
P
4
IN
P
3
HI
N
T
1
HI
N
T
2
IN
P
2
IN
P
1
B
UZ0
VC
C
NU
B
UZMD
KT
VP
MO
D
E
1
MO
D
E
0
KR
2
3
KR
2
2
KR
2
1
KR
2
0
KR
1
9
KR
1
8
KR
1
7
KR
1
6
ST
4
I/O controller
2. Pin description
Pin No.
PORT
RESET
Setting after RESET
Signal
name
Remark
I/O
Status
DATA
I/O
1
P70/AN0
I/O
I
—
I
R24
Key Return 24
Key return
2
P71/AN1
I/O
I
—
I
R25
Key Return 25
3
P72/AN2
I/O
I
—
I
R26
Key Return 26
4
AV
CC
I
—
—
I
NC
5
AV
R
I
—
—
I
NC
6
AV
SS
I
—
—
I
NC
7
P73/AN3
I/O
I
—
I
KR27
Key Return 27
Key return
8
P74/AN4
I/O
I
—
I
KR28
Key Return 28
9
P75/AN5
I/O
I
—
I
KR29
Key Return 29
10
P76/AN6/CAP0
I/O
I
—
I
KR30
Key Return 30
11
P77/AN7/CAP1
I/O
I
—
I
KR31
Key Return 31
12
MOD
I
H
‘H’
I
‘H’
13
X0
I
I
X0
System Clock
14
X1
I
I
X1
System Clock
15
V
SS
I
—
—
—
GND
GND
16
RST
I
I
IORES
System Reset
17
P00
I/O
I
—
I
KR0
Key Return 0
Key return
18
P01
I/O
I
—
I
KR1
Key Return 1
19
P02
I/O
I
—
I
KR2
Key Return 2
20
P03
I/O
I
—
I
KR3
Key Return 3
21
P04
I/O
I
—
I
KR4
Key Return 4
22
P05
I/O
I
—
I
KR5
Key Return 5
23
P06
I/O
I
—
I
KR6
Key Return 6
24
P07
I/O
I
—
I
KR7
Key Return 7
25
P10
I/O
I
—
I
KR8
Key Return 8
26
P11
I/O
I
—
I
KR9
Key Return 9
27
P12
I/O
I
—
I
KR10
Key Return 10
28
P13
I/O
I
—
I
KR11
Key Return 11
29
P14
I/O
I
—
I
KR12
Key Return 12
30
P15
I/O
I
—
I
KR13
Key Return 13
31
P16
I/O
I
—
I
KR14
Key Return 14
32
P17
I/O
I
—
I
KR15
Key Return 15
33
(OPEN)
—
—
—
—
—
OPEN
– 74 –
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