V54C3128(16/80/40)4V(BGA)
All of SDRAM operations are defined by states of control signals CS, RAS, CAS, WE, and DQM at the
positive edge of the clock. The following list shows the thruth table for the operation commands.
Operation
Row Activate
Read
Read w/Autoprecharge
Write
Write with Autoprecharge
Row Precharge
Precharge All
Mode Register Set
No Operation
Device Deselect
Auto Refresh
Self Refresh Entry
Self Refresh Exit
Notes:
1. V = Valid , x = Don’t Care, L = Low Level, H = High Level
2. CKEn signal is input level when commands are provided, CKEn-1 signal is input level one clock before the commands
are provided.
3. These are state of bank designated by BS0, BS1 signals.
4. Power Down Mode can not entry in the burst cycle.
CILETIV LESOM
Operation Definition
Device
State
Idle
3
Active
3
Active
3
Active
3
Active
3
Any
Any
Idle
Any
Any
Idle
Idle
Idle
(Self Refr.)
Idle
Active
4
Any
(Power
Down)
Active
Active
CKE
n-1
H
H
H
H
H
H
H
H
H
H
H
H
CKE
n
X
X
X
X
X
X
X
X
X
X
H
L
CS
L
L
L
L
L
L
L
L
L
H
L
L
H
RAS
L
H
H
H
H
L
L
L
H
X
L
L
X
H
X
H
X
H
X
X
CAS
H
L
L
L
L
H
H
L
H
X
L
L
X
H
X
H
X
H
X
X
WE
H
H
H
L
L
L
L
L
H
X
H
H
X
X
X
X
X
L
X
X
DQM
X
X
X
X
X
X
X
X
X
X
X
X
A0-9,
A11
V
V
V
V
V
X
X
V
X
X
X
X
A10
V
L
H
L
H
L
H
V
X
X
X
X
BS0
BS1
V
V
V
V
V
V
X
V
X
X
X
X
L
H
L
H
X
X
X
X
Power Down Entry
H
L
L
H
X
X
X
X
Power Down Exit
L
H
L
X
X
X
X
X
X
Data Write/Output Enable
Data Write/Output Disable
H
H
X
X
L
H
X
X
X
X
X
X
V54C3128(16/80/40)4V(BGA) Rev. 1.2 September 2001
7