EM488M1644VTD
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5. Command Truth Table for CKE
Current
state
CKE /CS /R /C /W Addr.
Action
Notes
n-1
n
X
H
H
H
H
L
Self refresh
H
L
X
H
L
X
X
H
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
H
L
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
INVALID, CLK (n – 1) would exit self refresh
Self refresh recovery
L
Self refresh recovery
L
L
ILLEGAL
L
L
X
X
X
H
L
ILLEGAL
L
X
H
L
X
X
H
H
L
Maintain self refresh
Self refresh
recovery
H
H
H
H
H
H
H
H
H
L
H
H
H
H
L
Idle after tRC
Idle after tRC
L
ILLEGAL
L
X
X
H
L
ILLEGAL
H
L
X
H
H
L
ILLEGAL
L
ILLEGAL
L
L
ILLEGAL
L
L
X
X
X
X
X
X
H
L
ILLEGAL
Power
down
X
H
L
X
X
X
H
L
X
X
X
X
H
L
INVALID, CLK(n-1) would exit power down
Exit power down→ Idle
L
Maintain power down mode
Refer to operations in Operative Command Table
Refer to operations in Operative Command Table
Refer to operations in Operative Command Table
Refresh
Both banks
idle
H
H
H
H
H
H
H
H
H
H
L
H
H
H
H
H
L
L
L
L
X
L
L
L
Op-Code Refer to operations in Operative Command Table
Refer to operations in Operative Command Table
Refer to operations in Operative Command Table
Refer to operations in Operative Command Table
H
L
X
H
L
X
X
H
L
X
X
X
H
L
L
L
L
L
L
L
X
Self refresh
1
1
1
2
L
L
L
L
Op-Code Refer to operations in Operative Command Table
X
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
X
X
X
X
X
Power down
Row active
Any state
H
L
Refer to operations in Operative Command Table
Power down
H
H
L
Refer to operations in Operative Command Table
Begin clock suspend next cycle
Exit clock suspend next cycle
Maintain clock suspend
X
X
X
other than
H
L
L
listed above
Remark : H = High level, L = Low level, X = High or Low level (Don't care)
Notes: 1. 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.
2. Must be legal command as defined in Operative Command Tabl
16
EOREX [ EOREX CORPORATION ]
