W949D6DB Datasheet, PDF (36/60 Pages) Winbond – Standard Self Refresh Mode

W949D6DB / W949D2DB
8.6.2 Basic Write Timing Parameters
Basic Write timing parameters for DQs are shown in below figure; they apply to all Write operations.
Input data appearing on the data bus, is written to the memory array subject to the DM input logic level
appearing coincident with the data. If a given DM signal is registered Low, the corresponding data will
be written to the memory; if the DM signal is registered High, the corresponding data inputs will be
ignored, and a write will not be executed to that byte / column location.
CK
CK
Case 1:
tDQSS = min
DQS
DQ, DM
Case 2:
tDQSS = max
DQS
DQ, DM
t_CK
t_CH
t_CL
t_DQSS
t_DQSH
t_DSH
t_WPRES
t_{WPRE tDH}
t_DS
DI n
t_DQSS
t_DQSL
t_DQSH
t_WPRES
t_{WPRE tDS} t_DH
DI n
t_DSH
t_WPST
t_DSS
t_DQSL
t_DSS
t_WPST
= Don't Care
1) DI n = Data In for column n
2) 3 subsequent elements of Data In are applied in the programmed order following DI n.
3) tDQSS: each rising edge of DQS must fall within the +/-25% window of the corresponding positive clock edge.
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Publication Release Date: Oct. 08, 2014
Revision: A01-003