EtronTech
EM6A9320
4Mx32 DDR SDRAM
Figure 10. Self Refresh Timimg
CK
200xCK
tSREX
CMD
CKE
SREF
SREX
NOP
CMD
Self Refresh Entry Self Refresh Exit
After 200 x CK, Command can be active
Figure 11. Precharge Command
CK
tRAS
tRP
tRC
CMD
ACT
RA
PRE
ACT
RA
A0-11
BA0-1
BA
BA
BA
Figure 12. Power Up Sequence
CK
200uS
NOP
tRP
tMRD
200xCK
tRP
tRFC
CMD
NOP PREA
EMRS
MRS
PREA
Precharge All
AREF AREF
MRS
Power Up Precharge All
wait 200uS
EMRS set
2 or more
Auto Refresh
MRS set
with A8=L
MRS set
Reset DLL
with A8=H
Figure 13. Mode Register Set Timing
CK
1xCK
tRP
tMRD
CMD
PREA
Precharge All
MRS CMD
MRS set After 1 x CK, Command can be active
Figure 14. Power Down Mode
CK
CMD
CKE
PRE NOP NOP
NOP
CMD
tPDEX
Power Down Mode Entry
Power Down Mode Exit
16
Rev 0.6
May. 2006