K4C561638C-TCD4000 Datasheet, PDF (33/42 Pages) Samsung semiconductor – 256Mb Network-DRAM

K4C5608/1638C
256Mb Network-DRAM
Power Down Timing (CL=4)
Write cycle to Power Down Mode
0
1
2
3
CLK
CLK
Command _WRA
LAL
PD
BL=4
DQS
(Input)
DQ
(Input)
WL=3
Hi-Z
Hi-Z
4
5
6
7
8
9
n-1
n
n+1 n+2
DESL
x
t_IH t_IS I_PD = 1 cycle
2 clock cycles
Hi-Z
I_RC(min), t_REFI(max)
I_RDA = 1 cycle
DESL
RoDrA
WRA
t_PDEX
Hi-Z
D0 D1 D2 D3
DQS
Hi-Z
(Input)
BL=2
DQ
Hi-Z
(Input)
D0 D1
Hi-Z
Hi-Z
Power Down Entry
Power Down Exit
Note : "x" is don’t care.
PD must be kept "High" level until WL+2 clock cycles from LAL command.
PD should be brought to high within t_REFI(max) to maintain the data written into cell.
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REV. 0.7 Aug. 2003