171
W9864G2IH-6Pindescription
W9864G2IH
Publication Release Date: Aug. 28, 2009
- 5 - Revision A03
5. PIN DESCRIPTION
PIN NUMBER PIN NAME
FUNCTION DESCRIPTION
24, 25, 26, 27, 60, 61, 62,
63, 64, 65, 66
A0−A10
Address
Multiplexed pins for row and column address.
Row address: A0−A10. Column address: A0−
A10 is sampled during a precharge command to
determine if all banks are to be precharged or
bank selected by BS0, BS1.
22, 23 BS0, BS1 Bank Select
Select bank to activate during row address latch
time, or bank to read/write during address latch
time.
2, 4, 5, 7, 8, 10, 11, 13, 31,
33, 34, 36, 37, 39, 40, 42,
45, 47, 48, 50, 51, 53, 54,
56, 74, 76, 77, 79, 80, 82,
83, 85
DQ0−DQ31
Data
Input/ Output
Multiplexed pins for data output and input.
20
CS
Chip Select
Disable or enable the command decoder. When
command decoder is disabled, new command is
ignored and previous operation continues.
19
RAS
Row Address
Strobe
Command input. When sampled at the rising
edge of the clock
RAS , CAS and
WE
define the operation to be executed.
18
CAS
Strobe
Referred to
RAS
17
WE
Write Enable
Referred to
RAS
16, 28, 59, 71
DQM0
−
DQM3
Input/Output
Mask
The output buffer is placed at Hi-Z (with latency
of 2) when DQM is sampled high in read cycle.
In write cycle, sampling DQM high will block the
write operation with zero latency.
68 CLK Clock Inputs
System clock used to sample inputs on the rising
edge of clock.
67 CKE Clock Enable
CKE controls the clock activation and
deactivation. When CKE is low, Power Down
mode, Suspend mode, or Self Refresh mode is
entered.
1, 15, 29, 43 V
DD
Power
Power for input buffers and logic circuit inside
DRAM.
44, 58, 72, 86 V
SS
Ground
Ground for input buffers and logic circuit inside
DRAM.
3, 9, 35, 41, 49, 55, 75, 81
V
DDQ
Power for I/O
Buffer
Separated power from VDD, to improve DQ
noise immunity.
6, 12, 32, 38, 46, 52, 78, 84
V
SSQ
Ground for I/O
Buffer
Separated ground from VSS, to improve DQ
noise immunity.
14, 21, 30, 57, 69, 70, 73 NC No Connection
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