EM44DM1688LBB
1. Command Truth Table
BA0
~
BA2
CKE
Command
Symbol
/CS /RAS /CAS /WE
A10
A12~A0
n-1
N
Device Deselect
No Operation
Read
DESL
NOP
H
H
H
X
X
H
H
L
L
X
H
H
X
H
L
X
H
H
X
X
V
X
X
L
X
X
V
READ
Read with Auto
Pre-charge
READA
WRIT
WRITA
ACT
H
H
H
H
H
H
H
H
H
H
L
L
L
L
L
H
H
H
L
L
L
H
L
V
V
V
V
V
H
L
V
V
V
V
X
Write
Write with Auto
Pre-charge
L
L
H
V
L
Bank Activate
H
H
H
L
Pre-charge Select
Bank
PRE
L
Pre-charge All
Banks
(Ext.) Mode
Register Set
PALL
H
H
H
H
L
L
L
L
H
L
L
L
X
H
V
X
V
EMRS
V*
Auto Refresh
REF
H
H
H
H
L
H
L
L
L
L
L
L
L
H
H
X
H
X
H
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Self refresh entry
SELF
L
H
L
X
H
X
H
X
H
X
H
Power Down Entry
Power Down Exit
PDEN
PDEX
L
H
H
H
L
L
H = High level, L = Low level, X = High or Low level (Don't care), V = Valid data input
* Please refers to the MRS, EMRS(1) & EMRS(2) setting
2. CKE Truth Table
CKE
Item
Command
*Note1
Symbol
/CS /RAS /CAS /WE Addr.
n-1
H
H
L
n
H
L
Any state
-
V
L
V
L
V
L
V
H
H
X
X
H
X
H
X
X
V
X
X
X
X
X
X
X
X
X
All Bank Idle
Self Refresh Entry
SELF
NOP
DESL
DESL
NOP
DESL
NOP
-
H
H
L
L
H
X
X
H
X
H
X
X
H
X
X
H
X
H
X
X
Self Refresh
All Bank Idle
Self Refresh Exit
L
H
H
L
H
H
L
Active or Precharge
Power Down Entry
L
H
H
L
H
L
Power Down Power Down Exit
L
Power Down Maintain power down
L
X
X
Self Refresh
Maintain self refresh
-
L
L
H = High level, L = Low level, X = High or Low level (Don't care)
Note1: Must be legal commands as defined in the command truth table. And any state other than list
above.
Nov. 2011
16/29
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