CK#
CK
COMMAND
T0
WRITE
ADDRESS
Bank a,
Col b
tDQSS (NOM)
DQS
tDQSS
DQ
DM
T1 T1n T2 T2n T3
NOP
NOP
NOP
tWR
DI
b
tDQSS (MIN)
DQS
DQ
DM
tDQSS
DI
b
tDQSS (MAX)
DQS
tDQSS
DQ
DI
b
DM
T4
PRE9
Bank,
(a or all)
64Mb: x32
DDR SDRAM
T5
T6
NOP
NOP
tRP
DON’T CARE
TRANSITIONING DATA
NOTE: 1. DI b = data-in for column b.
2. Subsequent element of data-in is applied in the programmed order following DI b.
3. An interrupted burst of 4 is shown; two data elements are written.
4. tWR is referenced from the first positive CK edge after the last data-in pair.
5. The PRECHARGE and WRITE commands are to the same bank.
6. A8 is LOW with the WRITE command (auto precharge is disabled).
7. DQS is required at T2 and T2n (nominal case) to register DM.
8. If the burst of 8 was used, DM would be required at T3 and T3n and not at T4 and T4n because the PRECHARGE
command would mask the last two data elements.
9. PRE = PRECHARGE command.
Figure 23
WRITE to Precharge – Interrupting
64Mb: x32 DDR SDRAM
2M32DDR-07.p65 – Rev. 12/01
33
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©2001, Micron Technology, Inc.