K4C89363AF Datasheet, PDF (47/58 Pages) Samsung semiconductor – 2,097,152-WORDS x 4 BANKS x 36-BITS DOUBLE DATA RATE Network-DRAM

K4C89363AF
Auto-Refresh Timing (CL=4, BL=4)
Unidirectional DS/QS mode
0
1
2
3
4
5
6
CLK
CLK
l_{R C} =5cycles
Command
RDA
LAL
DESL
WRA
REF
7
n-1
n
n+1
n+2
l_{R E F C} =19cycles
DESL
RDA
or
WRA
LAL or
MRS or
REF
Bank, Address
Bank,
UA
LA
LQS/UQS
(output)
l_{R C D} =1cycle
Low
DQ
(output)
Hi-Z
l_{R A S}= 4 c y c l e s
CL=4
Unidirectional DS/Free Running QS mode
CLK
CLK
l_{R C} =5cycles
Command
RDA
LAL
DESL
l_{R C D} =1cycle
Q0 Q1 Q2 Q 3
Low
Hi-Z
WRA
REF
l_{R E F C} =19cycles
DESL
RDA
or
WRA
LAL or
MRS or
REF
Bank, Address
LQS/UQS
(output)
Bank,
UA
LA
l_{R C D} = 1 c y c l e s
DQ
(output)
Hi-Z
l_{R A S}= 4 c y c l e s
CL=4
l_{R C D} =1cycles
Q0 Q1 Q2 Q 3
Hi-Z
Note : I n c a s e o f C L = 4 , I_{R E F C} must be meet 19 clock cycles.
When the Auto-Refresh operation is perfomed, the synthetic average interval of Auto-Refresh command
specified by t_{R E F I} m u s t b e s a t i s f i e d .
t_{R E F I} is average interval time in 8 Refresh cycles that is sampled randomly.
CLK
t₁
WRA REF
t₂
WRA REF
t₃
WRA REF
t₇
t₈
WRA REF
WRA REF
8 Refresh cycle
t_{R E F I =} ^{Total time of 8 Refresh cycle} ₌ ^{t1 + t2 + t3 + t4 +t 5 +t 6 +t 7 +t 8}
8
8
t_{R E F I} is specified to avoid partly concentrated current of Refresh operation that is acivated
larger are than Read/Write operation.
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REV. 0.0 Sep. 2002