eorex
Preliminary
EM488M3244VBC
2. DQM Truth Table
CKE
/CS
Command
Symbol
n-1
n
Data Write/Output Enable
Data Mask/Output Disable
ENB
H
H
X
X
H
L
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
Item
Command
Symbol
/CS /RAS /CAS /WE Addr.
n-1
H
n
L
L
Activating
Any
Clock Suspend Mode Entry
Clock Suspend Mode
X
X
X
X
X
X
X
X
X
X
L
Clock
Suspend
Clock Suspend Mode Exit
L
H
X
X
X
X
X
Idle
Idle
CBR Refresh Command
Self Refresh Entry
REF
H
H
L
L
L
L
L
L
L
H
H
H
X
X
X
X
X
X
X
X
X
SELF
H
L
H
H
L
L
H
X
X
X
H
X
X
X
Self Refresh
Self Refresh Exit
L
H
L
H
X
X
Idle
Power Down Entry
Power Down Exit
Power Down
H
Remark H = High level, L = Low level, X = High or Low level (Don't care)
May. 2007
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