K4D263238D Datasheet, PDF (5/18 Pages) Samsung semiconductor – 1M x 32Bit x 4 Banks Double Data Rate Synchronous DRAM with Bi-directional Data Strobe and DLL

K4D263238D
128M DDR SDRAM
INPUT/OUTPUT FUNCTIONAL DESCRIPTION
Symbol
Type
Function
CK, CK^*1
Input
The differential system clock Input.
All of the inputs are sampled on the rising edge of the clock except
DQ′s and DM′s that are sampled on both edges of the DQS.
CKE
Input
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
Input
CS enables the command decoder when low and disabled the com-
mand decoder when high. When the command decoder is disabled,
new commands are ignored but previous operations continue.
RAS
Input
Latches row addresses on the positive going edge of the CK with
RAS low. Enables row access & precharge.
CAS
Input
Latches column addresses on the positive going edge of the CK with
CAS low. Enables column access.
WE
Input
Enables write operation and row precharge.
Latches data in starting from CAS, WE active.
DQS
Input/Output
Data input and output are synchronized with both edge of DQS.
DM0 ~ DM3
Input
Data In mask. Data In is masked by DM Latency=0 when DM is high
in burst write. DM0 for DQ0 ~ DQ7, DM1 for DQ8 ~ DQ15, DM2 for
DQ16 ~ DQ23, DM3 for DQ24 ~ DQ31.
DQ0 ~ DQ31
Input/Output
Data inputs/Outputs are multiplexed on the same pins.
BA0, BA1
Input
Selects which bank is to be active.
A0 ~ A11
Input
Row/Column addresses are multiplexed on the same pins.
Row addresses : RA0 ~ RA11, Column addresses : CA0 ~ CA7.
Column address CA8 is used for auto precharge.
VDD/VSS
Power Supply
Power and ground for the input buffers and core logic.
VDDQ/VSSQ
Power Supply
Isolated power supply and ground for the output buffers to provide
improved noise immunity.
VREF
Power Supply
Reference voltage for inputs, used for SSTL interface.
MCL
Must Connect Low
Must connect Low
*1 : The timing reference point for the differential clocking is the cross point of CK and CK.
For any applications using the single ended clocking, apply VREF to CK pin.
-5-
Rev. 1.3 (Jul. 2002)