w9425g6eb Winbond Electronics Corp America, w9425g6eb Datasheet - Page 48

• Manufacturer Part Number: w9425g6eb
• Description: 4 M ? 4 Banks ? 16 Bits Ddr Sdram
• Manufacturer: Winbond Electronics Corp America

11.23 Auto Refresh Cycle
Note: CKE has to be kept “High” level for Auto-Refresh cycle.
11.24 Precharged/Active Power Down Mode Entry and Exit Timing
Note:
1. If power down occurs when all banks are idle, this mode is referred to as precharge power down.
2. If power down occurs when there is a row active in any bank, this mode is referred to as active power down.
11.25 Input Clock Frequency Change during Precharge Power Down Mode Timing
CLK
CLK
CMD
CMD
CLK
CLK
CKE
CLK
CLK
CMD
CKE
PREA
t
RP
Precharge/Activate
NOP
Note 1,2
CMD
NOP
Minmum 2 clocks
required before
changing frequency
NOP
t
RP
t
IH
NOP
t
IS
Entry
Frequency Change
Occurs here
t
CK
AREF
Stable new clock
before power down exit
- 48 -
NOP
t
RFC
t
IH
t
NOP
IS
AREF
t
IS
NOP
Exit
Publication Release Date:Feb. 12, 2009
RESET
DLL
200 clocks
CMD
NOP
NOP
t
RFC
W9425G6EB
NOP
NOP
CMD
CMD
Revision A02