W949D6DB Datasheet, PDF (46/60 Pages) Winbond – Standard Self Refresh Mode

W949D6DB / W949D2DB
8.12 Power Down
Power-down is entered when CKE is registered Low (no accesses can be in progress). If power-down
occurs when all banks are idle, this mode is referred to as precharge power-down; if power-down occurs
when there is a row active in any bank, this mode is referred to as active power-down.
Entering power-down deactivates the input and output buffers, excluding CK, CK and CKE. In power-
down mode, CKE Low must be maintained, and all other input signals are “Don’t Care”. The minimum
power-down duration is specified by tCKE. However, power-down duration is limited by the refresh
requirements of the device.
The power-down state is synchronously exited when CKE is registered High (along with a NOP or
DESELECT command). A valid command may be applied tXP after exit from power-down.
For Clock Stop during Power-Down mode, please refer to the Clock Stop subsection in this specification.
8.12.1 Power-Down Entry and Exit
CK
CK
t_RP
CKE
Command PRE
NOP
NOP
Address
t_CKE
t_XP
NOP
NOP
NOP
Valid
Valid
A10 (AP)
DQ
Pre All
High-z
Power Down
Entry
Precharge Power-Down mode shown; all banks are idle and t_RP
is met when Power-down Entry command is issued
Exit from
Power Down
Valid
Any
Command
= Don't Care
- 46 -
Publication Release Date: Oct. 08, 2014
Revision: A01-003