Column Address StrobeVSSGround
Write EnableVDDQPower for DQ′s
DQSData StrobeV
DMiData MaskMCLMust Connect Low
RFUReserved for Future Use
0 ~A11Address Input
SSQGround for DQ′s
-4-
Rev. 1.3 (Jul. 2002)
K4D263238D
INPUT/OUTPUT FUNCTIONAL DESCRIPTION
SymbolTypeFunction
The differential system clock Input.
CK, CK
*1
CKEInput
CS
Input
Input
All of the inputs are sampled on the rising edge of the clock except
′sandDM′s that are sampled on both edges of the DQS.
DQ
Activates the CK signal when high and deactivates the CK signal
when low. By deactivating the clock, CKE low indicates the Power
down mode or Self refresh mode.
CS
enables the command decoder when low and disabled the command decoder when high. When the command decoder is disabled,
new commands are ignored but previous operations continue.
128M DDR SDRAM
RAS
CAS
WE
Input
Input
Input
Latches row addresses on the positive going edge of the CK with
RAS
low. Enables row access & precharge.
Latches column addresses on the positive going edge of the CK with
CAS
low. Enables column access.
Enables write operation and row precharge.
Latches data in starting from CAS
,WEactive.
DQSInput/OutputData input and output are synchronized with both edge of DQS.
Data In mask. Data In is masked by DM Latency=0 when DM is high
0 ~DM3Input
DM
in burst write. DM0 for DQ0 ~DQ7, DM1 for DQ8 ~DQ15, DM2 for
16 ~DQ23, DM3 for DQ24 ~DQ31.
DQ
DQ0 ~DQ31Input/OutputData inputs/Outputs are multiplexed on the same pins.
BA
0,BA1InputSelects which bank is to be active.
Row/Column addresses are multiplexed on the same pins.
0 ~A11Input
A
V
DD/VSSPower SupplyPower and ground for the input buffers and core logic.