DDR SDRAM 256Mb E-die (x4, x8)
DDR SDRAM
B3
A2
B0
(DDR266@CL=2.5))
(DDR333@CL=2.5))
(DDR266@CL=2.0)
Parameter
Symbol
Unit
Note
Min
12
Max
Min
15
Max
Min
15
Max
Mode register set cycle time
DQ & DM setup time to DQS
DQ & DM hold time to DQS
tMRD
tDS
ns
ns
ns
0.45
0.5
0.5
j, k
j, k
tDH
0.45
0.5
0.5
Control & Address input pulse width
DQ & DM input pulse width
Power down exit time
tIPW
tDIPW
tPDEX
tXSNR
tXSRD
tREFI
2.2
1.75
6
2.2
1.75
7.5
2.2
1.75
7.5
ns
ns
8
8
ns
Exit self refresh to non-Read command
Exit self refresh to read command
Refresh interval time
75
75
75
ns
200
200
200
tCK
us
7.8
-
7.8
-
7.8
-
4
tHP
-tQHS
tHP
-tQHS
tHP
-tQHS
Output DQS valid window
Clock half period
tQH
tHP
ns
ns
11
tCLmin
or tCHmin
tCLmin
or tCHmin
tCLmin
or tCHmin
-
-
-
10, 11
Data hold skew factor
tQHS
0.55
0.6
0.75
0.6
0.75
0.6
ns
11
2
DQS write postamble time
tWPST
0.4
18
0.4
20
0.4
20
tCK
Active to Read with Auto precharge
command
tRAP
tDAL
Autoprecharge write recovery +
Precharge time
(tWR/tCK)
+
(tWR/tCK)
+
(tWR/tCK)
+
tCK
13
(tRP/tCK)
(tRP/tCK)
(tRP/tCK)
Rev. 1.3 April, 2005
SAMSUNG [ SAMSUNG ]
