eorex
EM488M1644VTE
5. Command Truth Table for CKE
CKE
Current State
/CS /R /C /W
Addr.
Action
n-1
n
INVALID, CLK(n-1) would exit self
refresh
H
X
X
X
X
X
X
L
L
L
L
L
H
H
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
L
H
L
L
L
X
H
L
L
L
H
L
L
L
X
H
H
L
X
X
H
H
L
X
H
H
L
X
H
L
X
X
X
H
L
X
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
ILLEGAL
Maintain self refresh
Idle after tRC
Idle after tRC
ILLEGAL
ILLEGAL
ILLEGAL
Self Refresh
Self Refresh
Recovery
L
L
L
ILLEGAL
ILLEGAL
ILLEGAL
X
INVALID, CLK(n-1) would exit
power down
Exit power down → Idle
Maintain power down mode
H
X
X
X
X
X
X
Power Down
L
L
H
L
X
X
H
L
L
L
L
H
L
X
X
X
H
L
L
L
X
H
L
X
X
X
X
H
L
X
X
X
X
X
H
L
X
X
X
X
X
H
H
H
H
H
H
H
H
H
H
H
H
H
L
L
L
L
Refer to operations in Operative
Command Table
X
Refresh
L
Op-Code
Refer to operations in Operative
Command Table
X
X
H
Both Banks
Idle
L
Self refresh (Note 17)
Refer to operations in Operative
Command Table
Power down (Note 17)
Refer to operations in Operative
Command Table
Power down (Note 17)
Refer to operations in Operative
Command Table
H
H
L
L
L
L
H
X
L
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
H
L
Row Active
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
Dec. 2007
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