EM484M1644VTA_15 Datasheet, PDF (18/19 Pages) Eorex Corporation – Synchronous DRAM

eorex
EM484M1644VTA
5. Command Truth Table for CKE
Current State
Self Refresh
Self Refresh
Recovery
Power Down
Both Banks
Idle
Row Active
Any State Other
than Listed above
CKE
n-1 n
HX
LH
LH
LH
LH
LL
HH
HH
HH
HH
HL
HL
HL
HL
HX
LH
LL
HH
HH
HH
HH
HH
HL
HL
HL
HL
HL
LX
HX
LX
HH
HL
/CS /R /C /W Addr.
Action
X XX X
X
INVALID, CLK(n-1) would exit self
refresh
H XX X
X
Self refresh recovery
L HH X
X
Self refresh recovery
L HL X
X
ILLEGAL
L LXX
X
ILLEGAL
X XX X
X
Maintain self refresh
H XX X
X
Idle after tRC
L HH X
X
Idle after tRC
L HL X
X
ILLEGAL
L LXX
X
ILLEGAL
H XX X
X
ILLEGAL
L HH X
X
ILLEGAL
L HL X
X
ILLEGAL
L LXX
X
ILLEGAL
X XX X
X
INVALID, CLK(n-1) would exit
power down
X XX X
X
Exit power down → Idle
X XX X
X
Maintain power down mode
H XX X
Refer to operations in Operative
L HX X
Command Table
L LHX
L LLH
X
Refresh
L L L L Op-Code
H XX X
L HX X
L LHX
Refer to operations in Operative
Command Table
L LLH
X
Self refresh ^{(Note 17)}
L L L L Op-Code ^{Refer to operations in Operative}
Command Table
X XX X
X
Power down ^{(Note 17)}
X XX X
X
Refer to operations in Operative
Command Table
X XX X
X
Power down ^{(Note 17)}
X XX X
Refer to operations in Operative
Command Table
X XX X
Begin clock suspend next cycle
X
(Note 18)
L H X XX X
X
Exit clock suspend next cycle
L L X XX X
X
Maintain clock suspend
Remark: H = High level, L = Low level, X = High or Low level (Don't care)
Notes 17: Self refresh can be entered only from the both banks idle state.
Power down can be entered only from both banks idle or row active state.
Notes 18: Must be legal command as defined in Operative Command Table
Apr. 2014
17/18
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