Sharp FACSIMILE FO-4500 Service Manual page 108

FO-4500H
514260-70J (IC7, 10)
I/O4
I/O5
I/O6
I/O7
WE
RAS
SOJ
VCC 1
42
I/O0 2
41
I/O1 3
40
I/O2 4
39
I/O3 5
38
VCC 6 37
I/O4 7
36
I/O5 8
35
I/O6 9
34
I/O7 10
33
N.C. 11
32
N.C. 12
31
WE 13
30
RAS 14
29
N.C. 15
28
N.C.
16 27
A0
17 26
A1
18 25
A2 19
24
A3 20 23
VCC 21 22 VSS
(Top view)
ROW ROW ROW
DETECTOR DETECTOR DETECTOR
SELECTOR SELECTOR
I/O4
I/O3
I/O2 I/O1
BUFFER
I/O3 I/O2 I/O1
BUFFER BUFFER BUFFER
I/O5
BUFFER
I/O6
BUFFER
I/O7
BUFFER
ADDRESS A0, A1, A2, A3
SELECTOR SELECTOR
ROW ROW ROW
DETECTOR DETECTOR DETECTOR
VSS
I/O15
I/O14
I/O13
Pin name
I/O12
A0 to A9 Address input
VSS
A0 to A9 Refresh address input
Data-in/Data-out
I/O0 to I/O15
I/O11
Row address strobe
RAS
I/O10
Column address strobe
UCAS, LCAS
I/O9
Read/Write enable
WE
I/O8
Output enable
OE
N.C.
Vcc
Power supply
Vss Ground
LCAS
N.C No connection
UCAS
OE
A9
A8
A7
A6
A5
A4
Fig. 6
ROW ROW ROW
DETECTOR DETECTOR DETECTOR
SELECTOR
I/O0 I/O15 I/O14
I/O0 I/O15 I/O14
BUFFER BUFFER BUFFER
PERIPHERAL CIRCUIT
ADDRESS A4, A5
SELECTOR
ROW ROW ROW
DETECTOR DETECTOR DETECTOR
Fig. 7
5 – 18
Function
ROW ROW
DETECTOR DETECTOR
SELECTOR
I/O11
I/O11
I/O12
I/O13
BUFFER
I/O13 I/O12
BUFFER BUFFER
I/O10
I/O10
BUFFER
I/O9
I/O9
BUFFER
I/O8
I/O8
BUFFER
LCAS
UCAS
OE
A6, A7, A8
SELECTOR
ROW ROW
DETECTOR DETECTOR