Service manual

CD-BK260V/CD-BK2700V/CD-BK280V
– 54 –
ICM1 VHi1625635T-1: DRAM (1625635T)
Figure 54 BLOCK DIAGRAM OF IC
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.
Port NamePin No.
Function
In this unit, the terminal with asterisk mark (*) is (open) terminal which is not connected to the outside.
RAS
LCAS
UCAS
WE
A0
A1
A2
A3
A4
A5
A6
A7
A8
VCC
VSS
I/O0
I/O1
I/O7
I/O8
I/O9
I/O15
OE
Lowar
Upper
Clock generating
circuit
Lower data
Input buffer
Lower data
Output buffer
Coidmn decoder
Upper data
Input buffer
A0-A8
A0-A8
I/O control circuit
Memory cell array
Upper data
Output buffer
Roe decoder
Row and column address buffer
14
29
28
13
16
17
18
19
22
23
24
25
26
27
39
32
31
10
3
2
40
35
21
1
20