V54C3256(16/80/40)4V(T/S/B)
Clock Enable (CKE) Truth Table:
CKE
n-1
CKE
n
STATE(n)
CS
RAS
CAS
WE
Addr ACTION
Self-Refresh6
H
L
L
L
L
L
L
X
H
H
H
H
H
L
X
H
L
X
X
H
H
H
L
X
X
H
H
L
X
X
H
L
X
X
X
X
X
X
X
INVALID
EXIT Self-Refresh, Idle after tRC
EXIT Self-Refresh, Idle after tRC
ILLEGAL
L
L
L
X
X
X
ILLEGAL
ILLEGAL
X
X
X
X
NOP (Maintain Self-Refresh)
Power-Down
H
L
L
L
L
L
L
X
H
H
H
H
H
L
X
H
L
X
X
H
H
H
L
X
X
H
H
L
X
X
H
L
X
X
X
X
X
X
X
X
X
X
INVALID
EXIT Power-Down, > Idle.
EXIT Power-Down, > Idle.
ILLEGAL
L
L
ILLEGAL
L
X
X
ILLEGAL
X
X
NOP (Maintain Low-Power Mode)
All. Banks
Idle7
H
H
H
H
H
H
H
H
L
H
L
L
L
L
L
L
L
L
X
H
L
L
L
L
L
L
X
X
X
H
H
H
L
X
X
H
H
L
X
X
H
L
X
X
X
X
X
X
X
X
X
Refer to the function truth table
Enter Power- Down
Enter Power- Down
ILLEGAL
X
X
H
L
ILLEGAL
H
L
ILLEGAL
L
Enter Self-Refresh
ILLEGAL
L
L
X
X
X
NOP
Abbreviations:
RA = Row Address
BS = Bank Address
AP = Auto Precharge
CA = Column Address
Notes for SDRAM function truth table:
1. Current State is state of the bank determined by BS. All entries assume that CKE was active (HIGH) during the preceding clock cycle.
2. Illegal to bank in specified state; Function may be legal in the bank indicated by BS, depending on the state of that bank.
3. Must satisfy bus contention, bus turn around, and/or write recovery requirements.
4. NOP to bank precharging or in Idle state. May precharge bank(s) indicated by BS (andAP).
5. Illegal if any bank is not Idle.
6. CKE Low to High transition will re-enable CLK and other inputs asynchronously. A minimum setup time must be satisfied before any
command other than EXIT.
7. Power-Down and Self-Refresh can be entered only from the All Banks Idle State.
8. Must be legal command as defined in the SDRAM function truth table.
V54C3256(16/80/40)4V(T/S/B) Rev. 1.6 September 2002
48
MOSEL [ MOSEL VITELIC, CORP ]
