k4j55323qi Samsung Semiconductor, Inc., k4j55323qi Datasheet - Page 17

• Manufacturer Part Number: k4j55323qi
• Description: 256mbit Gddr3 Sdram
• Manufacturer: Samsung Semiconductor, Inc.

K4J55323QI
7.6 Clock frequency change sequence during the device operation
Existing tCK is in DLL-on mode while desired tCK is in DLL-off mode
Both existing tCK and desired tCK are in DLL-On mode
Clock frequency change in case existing tCK is in DLL-off mode while desired tCK is in DLL-on mode
CK
CK
CMD
CK
CK
CMD
- Issue Precharge All Banks command
- Issue EMRS command to disable the DLL
- Issue Precharge All Banks command
- Change the frequency from existing to desired.
- Issue Auto-Refresh command at least two. Issue MRS command
- Change frequency from existing frequency to desired frequency
- Issue Precharge All Banks command
- Issue MRS command to reset the DLL while other fields are valid and required 20K tCK to lock the DLL
- Issue Precharge All Banks command. Issue at least Auto-Refresh command
- Issue Precharge All Banks command and issue EMRS command to disable the DLL.
- Issue Precharge All Banks command.
- Change the clock frequency from existing to desired
- Issue Precharge All Banks command.
- Issue EMRS command to enable the DLL
- Issue MRS command to reset the DLL and required 20K tCK to lock the DLL.
- Issue Precharge All Banks command.
- Issue Auto-Refresh command at least two
CMD
CK
CK
Precharge
All Banks
Precharge
PRE
All Banks
PRE
NOP
tRP
tRP
EMRS
OFF
DLL
EMRS
OFF
DLL
NOP
tMRD
tMRD
Precharge
All Banks
Precharge
PRE
All Banks
PRE
NOP
NOP
NOP
NOP
Frequency
Change
tFCHG
Frequency
NOP
Frequency
Change
tFCHG
Change
tFCHG
NOP
NOP
NOP
NOP
NOP
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Precharge
All Banks
PRE
Precharge
All Banks
PRE
AR
tRP
tRP
EMRS
DLL
On
Reset
MRS
MRS
DLL
tMRD
tMRD
Reset
MRS
Precharge
DLL
All Banks
NOP
PRE
tMRD
256M GDDR3 SDRAM
Precharge
All Banks
PRE
20tCK (DLL locking time)
NOP
NOP
20tCK (DLL locking time)
Rev. 1.3 May 2007
NOP
NOP
AR
AR
NOP
NOP