Sharp CD-BK260V Service Manual page 54

CD-BK260V/CD-BK2700V/CD-BK280V
ICM1 VHi1625635T-1: DRAM (1625635T)
Pin No. Port Name
1 VCC POWER SUPPLY.
2-10 I/O0-I/O7 DATA INPUT/OUTPUT.
11*,12* N.C. NOT USED.
13 WE READ/WRITE ENABLE.
14 RAS ROW ADDRESS STROBE.
15* N.C. NOT USED.
16-19 A0-A3 ADDRESS INPUT. (ROW/REFRESH: A0 TO A3) (COLUMN: A0 TO A3)
20 VCC POWER SUPPLY.
21 VSS GROUND.
22-26 A4-A8 ADDRESS INPUT. (ROW/REFRESH: A4 TO A8) (COLUMN: A4 TO A8)
27 OE OUTPUT ENABLE.
28,29 UCAS,LCAS COLUMN ADDROSS STROBE.
30* N.C. NOT USED.
31-34 I/O8-11 DATA INPUT/OUTPUT.
35 VSS GROUND.
36-39 I/O12-15 DATA INPUT/OUTPUT.
40 VSS GROUND.
In this unit, the terminal with asterisk mark (*) is (open) terminal which is not connected to the outside.
RAS
14
29
LCAS
28
UCAS
13
WE
A0 16
A0-A8
17
A1
A2
18
19
A3
A4
22
23
A5
A0-A8
A6 24
A7
25
A8
26
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Clock generating
circuit
Coidmn decoder
I/O control circuit
Memory cell array
Figure 54 BLOCK DIAGRAM OF IC
– 54 –
Function
Lower data
Lowar
Input buffer
Upper
Lower data
Output buffer
Upper data
Input buffer
Upper data
Output buffer
1
VCC
20
40
35
VSS
21
2
I/O0
3
I/O1
10
I/O7
31
I/O8
32
I/O9
39
I/O15
27
OE