W949D6DB Datasheet, PDF (24/60 Pages) Winbond – Standard Self Refresh Mode

W949D6DB / W949D2DB
Notes:
1. The table applies when both CKEn-1 and CKEn are HIGH, and after tXSR or tXP has been met if the previous state was Self
Refresh or Power Down.
2. DESELECT and NOP are functionally interchangeable.
3. All states and sequences not shown are illegal or reserved.
4. Current State Definitions:
Idle: The bank has been precharged, and tRP has been met.
Row Active: A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and no register accesses
are in progress.
Read: A READ burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
Write: A WRITE burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
5. Read with AP enabled and Write with AP enabled: The read with Auto Precharge enabled or Write with Auto Precharge
enabled states can be broken into two parts: the access period and the precharge period. For Read with AP, the precharge
period is defined as if the same burst was executed with Auto Precharge disabled and then followed with the earliest possible
PRECHARGE command that still accesses all the data in the burst. For Write with Auto precharge, the precharge period
begins when tWR ends, with tWR measured as if Auto Precharge was disabled. The access period starts with registration of
the command and ends where the precharge period (or tRP) begins. During the precharge period, of the Read with Auto
Precharge enabled or Write with Auto Precharge enabled states, ACTIVE, PRECHARGE, READ, and WRITE commands to
the other bank may be applied; during the access period, only ACTIVE and PRECHARGE commands to the other banks may
be applied. In either case, all other related limitations apply (e.g. contention between READ data and WRITE data must be
avoided).
6. AUTO REFRESH, SELF REFRESH, and MODE REGISTER SET commands may only be issued when all bank are idle.
7. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state
only.
8. READs or WRITEs listed in the Command column include READs and WRITEs with Auto Precharge enabled and READs
and WRITEs with Auto Precharge disabled.
9. Requires appropriate DM masking.
10. A WRITE command may be applied after the completion of data output, otherwise a BURST TERMINATE command must be
issued to end the READ prior to asserting a WRITE command.
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Publication Release Date: Oct. 08, 2014
Revision: A01-003