eorex
EM488M1644VBB
5. Command Truth Table for CKE
CKE
n-1
Current State
/CS /R /C /W
Addr.
Action
n
INVALID, CLK(n-1) would exit self
refresh
H
X
X
X
X
X
X
L
L
H
H
H
H
L
H
L
L
L
X
H
L
L
L
H
L
L
L
X
H
H
L
X
H
L
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Self refresh recovery
Self refresh recovery
ILLEGAL
Self Refresh
L
L
X
X
X
H
L
ILLEGAL
L
X
X
H
H
L
Maintain self refresh
Idle after tRC
Idle after tRC
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
H
H
H
H
H
H
H
H
H
H
H
H
L
X
X
H
L
Self Refresh
Recovery
X
H
H
L
L
L
L
X
INVALID, CLK(n-1) would exit
power down
H
X
X
X
X
X
X
Power Down
L
L
H
L
X
X
H
L
X
X
X
H
L
X
X
X
X
H
L
X
X
X
X
X
H
L
X
X
Exit power down → Idle
Maintain power down mode
H
H
H
H
H
H
H
H
H
H
H
H
H
L
Refer to operations in Operative
Command Table
L
L
L
X
Op-Code
Refresh
L
L
L
Refer to operations in Operative
Command Table
H
L
X
H
L
X
X
H
X
X
X
Both Banks
Idle
L
L
L
L
(Note 17)
H
H
L
L
L
L
H
X
Self refresh
L
Refer to operations in Operative
Command Table
(Note 17)
L
L
L
L
Op-Code
X
X
X
H
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Power down
Refer to operations in Operative
Command Table
(Note 17)
H
L
Row Active
Power down
Refer to operations in Operative
Command Table
H
Begin clock suspend next cycle
(Note 18)
Any State Other
than Listed above
H
L
X
X
X
X
X
L
L
H
L
X
X
X
X
X
X
X
X
X
X
Exit clock suspend next cycle
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
Jul. 2006
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