Sharp FO-780A, Service Manual

Page: 82 / 102

FO-780A
8 – 8
IC1: RH-IX2129SCZZ (M514800C-70J)
VCC 1
I/O0 2
I/O1
3
I/O2 4
I/O3 5
NC
6
WE 7
RAS 8
A9
9
A0 10
A1 11
A2 12
A3 13
VCC 14
28 VSS
27 I/O7
26 I/O6
25 I/O5
24 I/O4
23 CAS
22 OE
21 NC
20 A8
19 A7
18 A6
17 A5
16 A4
15 VSS
PIN DESCRIPTION
PIN
A0~A9
I/O0~I/O7
RAS
PIN NAME
ADDRESS INPUT
(LOW/REFRESH A0~A3
COLUMN A0~A3)
DATA I/O
LOW ADDRESS STROBE
PIN
CAS
PIN NAME
COLUMN ADDRESS STROBE
WE READ/WRITE INPUT
OE OUTPUT ENABLE
VCC POWER (+5V)
VSS CONNECTION
P-CH SENSE AMP
256K MEMORY CELL ARRAY
N-CH SENSE AMP
I/O BUS & COLUMN DETECTOR
N-CH SENSE AMP
256K MEMORY CELL ARRAY
P-CH SENSE AMP
256K MEMORY CELL ARRAY
N-CH SENSE AMP
I/O BUS & COLUMN DETECTOR
N-CH SENSE AMP
256K MEMORY CELL ARRAY
P-CH SENSE AMP
PERIPHERAL CIRCUIT
IO3
I/O2 BUFFER
IO2
I/O1 BUFFER
IO1
I/O0 BUFFER
IO0
P-CH SENSE AMP
256K MEMORY CELL ARRAY
N-CH SENSE AMP
I/O BUS & COLUMN DETECTOR
N-CH SENSE AMP
256K MEMORY CELL ARRAY
P-CH SENSE AMP
256K MEMORY CELL ARRAY
N-CH SENSE AMP
I/O BUS & COLUMN DETECTOR
N-CH SENSE AMP
256K MEMORY CELL ARRAY
P-CH SENSE AMP
I/O7 BUFFER
IO7
I/O6 BUFFER
IO6
I/O5 BUFFER
IO5
I/O4 BUFFER
IO4
P-CH SENSE AMP
COLUMN DETECTOR
P-CH SENSE AMP
PERIPHERAL CIRCUIT
P-CH SENSE AMP P-CH SENSE AMP
ROW ADDRESS BUFFER COLUMN ADDRESS BUFFER
ADDRESS A0~A9
A0~A9 A0~A8
RAS
CONTROL CIRCUIT
RAS
CAS
CONTROL CIRCUIT
CAS
WE
CONTROL CIRCUIT
WE
OE
CONTROL CIRCUIT
OE
ROW DETECTOR & PERIPHERAL CIRCUIT
BLOCK DIAGRAM
I/O3 BUFFER