HYB25D256400BT Datasheet, PDF (43/77 Pages) Infineon Technologies AG – 256-Mbit Double Data Rate SDRAM, Die Rev. B

HYB25D256[400/800/160]B[T/C](L)
256-Mbit Double Data Rate SDRAM, Die Rev. B
Write to Precharge: Nominal DQSS (2 bit Write), Interrupting (Burst Length = 4 or 8)
CK
CK
Command
Address
DQS
DQ
DM
T1
T2
T3
T4
T5
Write
BA a, COL b
NOP
NOP
t_DQSS (nom)
NOP
t_WR
2
PRE
BA (a or all)
DI a-b
3
3
1
1
DI a-b = Data In for bank a, column b.
An interrupted burst is shown, 2 data elements are written.
1 subsequent element of data in is applied in the programmed order following DI a-b.
t_WR is referenced from the first positive CK edge after the last desired data in pair.
The Precharge command masks the last 2 data elements in the burst.
A10 is Low with the Write command (Auto Precharge is disabled).
1 = Can be don't care for programmed burst length of 4.
2 = For programmed burst length of 4, DQS becomes don't care at this point.
3 = These bits are incorrectly written into the memory array if DM is low.
T6
NOP
t_RP
Don’t Care
Page 43 of 77
2003-01-09, V1.1