w942508ch Winbond Electronics Corp America, w942508ch Datasheet - Page 6

• Manufacturer Part Number: w942508ch
• Description: 8m X 4 Banks X 8 Bit Ddr Sdram
• Manufacturer: Winbond Electronics Corp America

5. PIN DESCRIPTION
6, 12, 52, 58, 64
4, 7, 10, 13, 14,
3, 9, 15, 55, 61
PIN NUMBER
2, 5, 8, 11, 56,
16, 17, 19, 20,
25, 43, 50, 53,
54, 57, 60, 63
59, 62, 65
23, 22, 21
34, 48, 66
1, 18, 33
28  32,
35  42
26, 27
45, 46
51
24
47
44
49
DQ0  DQ7
RAS , CAS ,
CLK,
PIN NAME
NC1, NC2
BS0, BS1
A0  A12
V
V
DQS
V
CKE
V
V
DM
WE
CS
DDQ
SSQ
REF
DD
SS
CLK
No Connection No connection
Power (+2.5V)
Ground for I/O
Clock Enable
Power (+2.5)
for I/O Buffer
Clock Inputs
Bank Select
Data Strobe
FUNCTION
Chip Select
Write Mask
Data Input/
Differential
Command
Reference
Address
Voltage
Ground
Output
Inputs
Buffer
Power for logic circuit inside DDR SDRAM.
Multiplexed pins for row and column address.
Row address: A0  A12.
Column address: A0  A9. (A10 is used for Auto Precharge)
Select bank to activate during row address latch time, or bank
to read/write during column address latch time.
The DQ0 – DQ7 input and output data are synchronized with
both edges of DQS.
DQS is Bi-directional signal. DQS is input signal during write
operation and output signal during read operation. It is Edge-
aligned with read data, Center-aligned with write data.
Disable or enable the command decoder. When command
decoder is disabled, new command is ignored and previous
operation continues.
Command inputs (along with
entered.
When DM is asserted
masked. DM is synchronized with both edges of DQS.
All address and control input signals are sampled on the
crossing of the positive edge of CLK and negative edge of
CKE controls the clock activation and deactivation. When CKE
is low, Power Down mode, Suspend mode, or Self Refresh
mode is entered.
V
Ground for logic circuit inside DDR SDRAM.
Separated power from V
noise.
Separated ground from V
noise.
CLK
REF
.
is reference voltage for inputs.
- 6 -
"
high
DESCRIPTION
DD
SS
, used for output buffer, to improve
"
, used for output buffer, to improve
in burst write, the input data is
CS
) define the command being
W942508CH