EM48AMM1684VTG
2. DQM Truth Table
CKE
/CS
Command
Symbol
n-1
n
Data write / output enable
ENB
H
H
x
x
H
L
Data mask / output disable
MASK
Upper byte write enable / output enable
Read
BSTH
READ
READA
WRIT
WRITA
ACT
H
H
H
H
H
H
H
H
H
x
x
x
x
x
x
x
x
x
L
L
L
L
L
L
L
L
L
Read with auto pre-charge
Write
Write with auto pre-charge
Bank activate
Pre-charge select bank
Pre-charge all banks
Mode register set
PRE
PALL
MRS
* H = High level, L = Low level, X = High or Low level (Don’t care), V = Valid data input
3. CKE Truth Table
CKE
Command
Command
Symbol
/CS /RAS /CAS /WE Addr.
n-1
H
L
n
L
Activating
Any
Clock suspend mode entry
Clock suspend mode
X
X
X
L
X
X
X
L
X
X
X
L
X
X
X
H
H
H
X
X
X
X
X
X
X
X
X
X
X
X
L
Clock suspend Clock suspend mode exit
L
H
H
L
Idle
Idle
CBR refresh command
Self refresh entry
REF
H
H
L
SELF
L
L
L
H
H
L
L
H
X
X
X
H
X
X
X
Self refresh
Self refresh exit
L
H
X
X
Idle
Power down entry
H
L
Power down Power down exit
H
*H = High level, L = Low level, X = High or Low level (Don't care), V = Valid data input
Jun. 2010
15/20
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