HYB25D256800CT Datasheet, PDF (50/94 Pages) Infineon Technologies AG – 256 Mbit Double Data Rate SDRAM

HYB25D256[16/40/80]0C[E/C/F/T](L)
256 Mbit Double-Data-Rate SDRAM
Functional Description
CK
CK
Command
Address
DQS
DQ
DM
T1
T2
T3
T4
T5
T6
Write
BAa, COL b
NOP
NOP
t_DQSS (nom)
DI a-b
NOP
Read
NOP
t_WTR
BAa, COL n
CL = 2
1
1
DI a-b = data in for bank a, column b.
An interrupted burst is shown, 4 data elements are written.
3 subsequent elements of data in are applied in the programmed order following DI a-b.
t_WTR is referenced from the first positive CK edge after the last desired data in pair.
The Read command masks the last 2 data elements in the burst.
A10 is Low with the Write command (Auto Precharge is disabled).
The Read and Write commands are not necessarily to the same bank.
1 = These bits are incorrectly written into the memory array if DM is low.
Don’t Care
Figure 25 Write to Read: Nominal DQSS, Interrupting (CAS Latency = 2; Burst Length = 8)
Data Sheet
50
Rev. 1.6, 2004-12