VIS
2.Truth Table
2.1 Command Truth Table
CKE
FUNCTION
Device deselect
No operation
Mode register set
Bank activate
Read
Read with auto precharge
Write
Write with auto precharge
Precharge select bank
Precharge all banks
Burst stop
CBR (Auto) refresh
Self refresh
Symbol
DESL
NOP
MRS
ACT
READ
READA
WRIT
WRITA
PRE
PALL
BST
REF
SELF
n-1
H
H
H
H
H
H
H
H
H
H
H
H
H
n
X
X
X
X
X
X
X
X
X
X
X
H
L
Preliminary
VG36648041CT
CMOS Synchronous Dynamic RAM
CS
H
L
L
L
L
L
L
L
L
L
L
L
L
RAS
X
H
L
L
H
H
H
H
L
L
H
L
L
CAS
X
H
L
H
L
L
L
L
H
H
H
L
L
WE
X
H
L
H
H
H
L
L
L
L
L
H
H
BA
X
X
L
V
V
V
V
V
V
X
X
X
X
A10
X
X
L
V
L
H
L
H
L
H
X
X
X
A11
A9 - A0
X
X
V
V
V
V
V
V
X
X
X
X
X
2.2 DQM Truth Table
CKE
FUNCTION
Data write/output enable
Data mask/output disable
Symbol
ENB
MASK
n-1
H
H
n-1
X
X
L
H
DQM
2.3 CKE Truth Table
CKE
Current State
Activating
Any
Clock suspend
Idle
Idle
Self refresh
Idle
Power down
Function
Clock suspend mode entry
Clock suspend
Clock suspend mode exit
CBR refresh command
Self refresh entry
Self refresh exit
Power down entry
Power down exit
REF
SELF
Symbol
n-1
H
L
L
H
H
L
L
H
L
n
L
L
H
H
L
H
H
L
H
CS
X
X
X
L
L
L
H
X
X
RAS
X
X
X
L
L
H
X
X
X
CAS
X
X
X
L
L
H
X
X
X
WE
X
X
X
H
H
H
X
X
X
Add -
ress
X
X
X
X
X
X
X
X
X
H : High level, L : Low level
X : High or Low level (Don’ care), V : Valid Data input
t
Document : 1G5-0153
Rev.1
Page 9
VML [ VANGUARD INTERNATIONAL SEMICONDUCTOR ]
