V54C3256(16/80/40)4V(T/S/B)
Complete List of Operation Commands
SDRAM Function Truth Table
CURRENT
1
STATE
CS
RAS
CAS
WE
BS
Addr
ACTION
Idle
H
L
L
L
L
L
L
L
X
X
X
X
X
X
NOP or Power Down
H
H
H
L
H
H
L
H
L
X
NOP
BS
BS
BS
BS
X
X
ILLEGAL2
X
H
L
X
ILLEGAL2
H
H
L
RA
AP
X
Row (&Bank) Active; Latch Row Address
NOP4
Auto-Refresh or Self-Refresh5
Mode reg. Access5
L
L
H
L
L
L
Op-
Code
Row Active
H
L
L
L
L
L
L
X
H
H
H
L
X
H
L
X
X
H
L
X
X
NOP
X
X
NOP
BS
BS
BS
BS
X
CA,AP
CA,AP
X
Begin Read; Latch CA; DetermineAP
Begin Write; Latch CA; DetermineAP
ILLEGAL2
L
H
H
L
H
L
L
AP
Precharge
L
X
X
ILLEGAL
Read
H
L
L
L
L
L
L
L
X
H
H
H
H
L
X
H
H
L
X
H
L
X
X
NOP (Continue Burst to End;>Row Active)
NOP (Continue Burst to End;>Row Active)
Burst Stop Command > Row Active
Term Burst, New Read, DetermineAP3
Term Burst, Start Write, DetermineAP3
ILLEGAL2
X
X
X
BS
BS
BS
BS
BS
X
H
L
CA,AP
CA,AP
X
L
H
H
L
H
L
L
AP
Term Burst, Precharge
L
X
X
ILLEGAL
Write
H
L
L
L
L
L
L
L
X
H
H
H
H
L
X
H
H
L
X
H
L
X
X
NOP (Continue Burst to End;>Row Active)
NOP (Continue Burst to End;>Row Active)
Burst Stop Command > Row Active
Term Burst, Start Read, DetermineAP3
Term Burst, New Write, DetermineAP3
ILLEGAL2
X
X
BS
BS
BS
BS
BS
X
X
H
L
CA,AP
CA,AP
X
L
H
H
L
H
L
L
AP
Term Burst, Precharge3
L
X
X
ILLEGAL
Read
H
L
L
L
L
L
L
L
X
H
H
H
H
L
X
H
H
L
X
H
L
X
X
NOP (Continue Burst to End;> Precharge)
with
X
X
NOP (Continue Burst to End;> Precharge)
Auto
BS
BS
X
X
ILLEGAL2
ILLEGAL2
ILLEGAL
ILLEGAL2
ILLEGAL2
ILLEGAL
Precharge
H
L
X
X
L
H
H
L
H
L
BS
BS
X
X
L
AP
X
L
X
V54C3256(16/80/40)4V(T/S/B) Rev. 1.6 September 2002
46
MOSEL [ MOSEL VITELIC, CORP ]
