EM48AM1644VBC Datasheet, PDF (18/19 Pages) Eorex Corporation – 256Mb (4M×4Bank×16) Synchronous DRAM

eorex
Preliminary
EM48AM1644VBC
5. Command Truth Table for CKE
Current State
Self Refresh
Self Refresh
Recovery
Power Down
Both Banks
Idle
Row Active
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
/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
L HH X
L HL X
X
Idle after t_RC
X
Idle after t_RC
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
L HX X
L LHX
Refer to operations in Operative
Command Table
L LLH
X
Refresh
L L L L Op-Code
H XX X
Refer to operations in Operative
L HX X
Command Table
L LHX
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 XX X
X
Refer to operations in Operative
Command Table
X
Power down ^{(Note 17)}
X XX X
Refer to operations in Operative
Command Table
Any State Other
than Listed above
H
L
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
May. 2007
18/19
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