w9425g8eh Winbond Electronics Corp America, w9425g8eh Datasheet - Page 7

• Manufacturer Part Number: w9425g8eh
• Description: 8m ? 4 Banks ? 8 Bits Ddr Sdram
• Manufacturer: Winbond Electronics Corp America

5. PIN DESCRIPTION
6, 12, 52, 58, 64
4, 7, 10, 13, 14,
PIN NUMBER
3, 9, 15, 55, 61
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
PIN NAME
DQ0 − DQ7
RAS , CAS ,
CLK,
BS0, BS1
A0 − A12
V
V
DQS
V
CKE
V
V
DM
WE
NC
CS
DDQ
SSQ
REF
DD
SS
CLK
No Connection
Power (+2.5V)
Ground for I/O
Clock Enable
Power (+2.5) Power for logic circuit inside DDR SDRAM.
for I/O Buffer
FUNCTION
Clock Inputs
Bank Select
Data Strobe
Chip Select
Write Mask
Data Input/
Differential
Command
Reference
Address
Voltage
Ground
Output
Inputs
Buffer
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.
No connection. (NC pin should be connected to GND or
floating)
CLK
REF
- 7 -
.
is reference voltage for inputs.
"
high
DESCRIPTION
Publication Release Date: Jul. 04
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
Revision A01
,
2008