K4D263238F
INPUT/OUTPUT FUNCTIONAL DESCRIPTION
Symbol
CK,
CK
*1
Input
Type
128M DDR SDRAM
Function
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.
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 com-
mand decoder when high. When the command decoder is disabled,
new commands are ignored but previous operations continue.
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, WE active.
Data 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
in burst write. DM
0
for DQ
0
~ DQ
7,
DM
1
for DQ
8
~ DQ
15,
DM
2
for
DQ
16
~ DQ
23,
DM
3
for DQ
24
~ DQ
31.
Data inputs/Outputs are multiplexed on the same pins.
Selects which bank is to be active.
Row/Column addresses are multiplexed on the same pins.
Row addresses : RA
0
~ RA
11
, Column addresses : CA
0
~ CA
7
.
Column address CA
8
is used for auto precharge.
Power and ground for the input buffers and core logic.
Isolated power supply and ground for the output buffers to provide
improved noise immunity.
Reference voltage for inputs, used for SSTL interface.
Must connect Low
CKE
Input
CS
Input
RAS
CAS
WE
DQS
DM
0
~ DM
3
DQ
0
~ DQ
31
BA
0
, BA
1
A
0
~ A
11
V
DD
/V
SS
V
DDQ
/V
SSQ
V
REF
MCL
Input
Input
Input
Input/Output
Input
Input/Output
Input
Input
Power Supply
Power Supply
Power Supply
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 V
REF
to CK pin.
- 5 -
Rev 1.1 (May 2003)
SAMSUNG [ SAMSUNG SEMICONDUCTOR ]
