W949D6DB Datasheet, PDF (43/60 Pages) Winbond – Standard Self Refresh Mode

W949D6DB / W949D2DB
8.10 Auto Refresh
AUTO REFRESH command is used during normal operation of the LPDDR SDRAM. This command is
non persistent, so it must be issued each time a refresh is required.
The refresh addressing is generated by the internal refresh controller. The LPDDR SDRAM requires
AUTO REFRESH commands at an average periodic interval of tREFI.
8.10.1 Auto Refresh Command
CK
CK
CKE
CS
(High)
RAS
CAS
WE
A0-An
BA0,BA1
= Don't Care
8.10.2 Auto Refresh Cycles Back-to-Back
An Auto Refresh cycle timing diagram is shown in below.
CK
CK
Command PRE
t_RP
NOP
Address
A10 (AP) Pre All
DQ
High-z
Ba A, Row n = Bank A, Row n
ARF
NOP
t_RFC
NOP
ARF
NOP
t_RFC
NOP
ACT
Ba,A
Row n
Row n
= Don't Care
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Publication Release Date: Oct. 08, 2014
Revision: A01-003