EtronTech
EM68916CWQA
Figure 3. State Diagram
CKEL
OCD
Initialization
calibration
Sequence
Self
Refreshing
PR
Setting
MR,
Idle
All banks
precharged
(E)MRS
REF
EMR(1)
EMR(2)
EMR(3)
Refreshing
ACT
Precharge
Power
Down
Automatic Sequence
Cammand Sequence
Activating
CKEL
CKEL
Active
Power
Down
Bank
Active
RD
WR
Reading
RD
Writing
WR
CKEL = CKE LOW, enter Power Down
CKEH = CKE HIGH, exit Power Down,exit Self Refresh
ACT = Activate
RDA
WRA
WR(A) = Write (with Autoprecharge)
RD(A) = Read (with Autoprecharge)
PR(A) = Precharge (All)
Reading
With
Autoprecharge
PR, PRA
Writing
With
Autoprecharge
PR, PRA
PR, PRA
(E)MRS = (Extended) Mode Register Set
SRF = Enter Self Refresh
Precharging
REF = Refresh
Note: Use caution with this diagram. It is indented to provide a floorplan of the possible state transitions and the
commands to control them, not all details. In particular situations involving more than one bank,
enabling/disabling on-die termination, Power Down entry/exit, timing restrictions during state transitions, among
other things, are not captured in full detail.
Etron Confidential
4
Rev. 1.1
Apr. 2009
ETRON [ ETRON TECHNOLOGY, INC. ]
