VIS
2.Truth Table
2.1 Command Truth Table
Preliminary
VG3617161DT
16Mb CMOS Synchronous Dynamic RAM
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
Symbol
DESL
NOP
MRS
ACT
READ
READA
WRIT
WRITA
PRE
PALL
BST
CKE
n-1 n
H
X
H
X
H
X
H
X
H
X
H
X
H
X
H
X
H
X
H
X
H
X
A9-
CS RAS CAS WE A11 A10 A0
H
X
X
X
X
X
X
L
H
H
H
X
X
X
L
L
L
L
L
X
V
L
L
H
H
V
V
V
L
H
L
H
V
L
V
L
H
L
H
V
H
V
L
H
L
L
V
L
V
L
H
L
L
V
H
V
L
L
H
L
V
L
X
L
L
H
L
X
H
X
L
H
H
L
X
X
X
2.2 DQM Truth Table
FUNCTION
Data write/output enable
Data mask/output disable
Upper byte write enable/output enable
Lower byte write enable/output enable
Upper byte write inhibit/output disable
Lower byte inhibit/output disable
Symbol
ENB
MASK
ENBU
ENBL
MASKU
MASKL
CKE
n-1
n-1
H
X
H
X
H
X
H
X
H
X
H
X
DQM
U
L
L
H
L
X
X
L
H
X
X
H
2.3 CKE Truth Table
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
Symbol
REF
SELF
CKE
n-1 n
HL
LL
LH
HH
HL
LH
LH
HL
LH
CS RAS CAS WE
XX
X
X
XX
X
X
XX
X
X
L
L
L
H
L
L
L
H
LH
H
H
HX
X
X
XX
X
X
XX
X
X
Add-
ress
X
X
X
X
X
X
X
X
X
H : High level, L : Low level
X : high or Low level(Dont’ care), V : Valid Data input
Document:1G5-0160
Rev.1
Page 10