K4C561638C-TCD4000 Datasheet, PDF (35/42 Pages) Samsung semiconductor – 256Mb Network-DRAM

K4C5608/1638C
256Mb Network-DRAM
Self-Refresh Entry Timing
CK
CK
Command
0
1
2
3
4
I_RCD = 1 cycle
I_REFC
WRA REF
t_FPDL(min) t_FPDL(max)
DESL
Auto Refresh
5
m-1
m
m+1
X ^*1
PD
t_QPDH
DQS
Hi-Z
(Output)
Self Refresh Entry
I_PDV*2
I_CKD = 16 cycleS ^*3
DQ
(Output)
Hi-Z
Qx
Note : 1. "X" is don’t care.
2. PD msut be brought to "Low" within the timing between t_FPDL(min) and t_FPDL(max) to Self Refresh mode
When PD is brought to "Low" after I_PDV, Network-DRAM perform Auto Refresh and enter Power down mode.
3. It is desirable that clock input is continued at least 16 clock cycles from REF command even though
PD is brought to "Low" for Self-Refresh Entry.
Self-Refresh Exit Timing
0
1
2
m-1
m
m+1 m+2
n-1
n
n+1
CK
CK
I_REFC
I_REFC
Command
X^*1
DESL^*3
WRA^*5 REF^*5
I_PDA = 1 cycle *4
IRCD = 1 cycle
DESL
Command Command
(1st)^*6
(2nd)^*6
I_RCD = 1 cycle
PD
DQS
Hi-Z
(Output)
t_PDEX
ILOCK
p-1
p
RDA^*7 LAL^*7
DQ
(Output)
Hi-Z
Self-Refresh Exit
Note : 1. "X" is don’t care.,
2. Clock should be stable prior to PD = "High" if clock input is suspended in Self-Refresh mode.
3. DESL command must be asserted during I_REFC after PD is brought to "High".
4. IPDA is defined from the first clock rising edge after PD is brought to "High".
5. It is desirable that one Auto-Refresh command is issued just after Self-Refresh Exit before any other operation.
6. Any command (except Read command) can be issued after I_REFC.
7. Read command (RDA+LAL) can be issued after ILOCK.
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REV. 0.7 Aug. 2003