µPD4564441, 4564841, 4564163
4.5 Command Truth Table for CKE
Current State
CKE
n–1 n
Self refresh
H×
LH
LH
LH
LH
LL
Self refresh recovery H H
HH
HH
HH
HL
HL
HL
HL
Power down
H×
LH
LH
LL
All banks idle
HH
HH
HH
HH
HH
HL
HL
HL
HL
HL
L×
Row active
H×
L×
Any state other than H H
listed above
HL
LH
LL
/CS /RAS /CAS /WE Address
Action
Notes
× × × ××
INVALID, CLK (n-1) would exit self refresh
H × × ××
Self refresh recovery
L H H ××
Self refresh recovery
L H L ××
ILLEGAL
L L × ××
ILLEGAL
× × × ××
Maintain self refresh
H × × ××
Idle after tRC
L H H ××
Idle after tRC
L H L ××
ILLEGAL
L L × ××
ILLEGAL
H × × ××
ILLEGAL
L H H ××
ILLEGAL
L H L ××
ILLEGAL
L L × ××
ILLEGAL
××××
INVALID, CLK (n – 1) would exit power down
H × × ××
EXIT power down → Idle
L H H H×
EXIT power down → Idle
× × × ××
Maintain power down mode
H× × ×
Refer to operations in Operative Command Table
LH× ×
Refer to operations in Operative Command Table
L LH×
Refer to operations in Operative Command Table
L L L H×
CBR (auto) refresh
L L L L Op-Code Refer to operations in Operative Command Table
H× × ×
Refer to operations in Operative Command Table
LH× ×
Refer to operations in Operative Command Table
L LH×
Refer to operations in Operative Command Table
L L L H×
Self refresh
1
L L L L Op-Code Refer to operations in Operative Command Table
× × × ××
Power down
1
× × × ××
Refer to operations in Operative Command Table
× × × ××
Power down
1
××××
Refer to operations in Operative Command Table
× × × ××
Begin clock suspend next cycle
2
× × × ××
Exit clock suspend next cycle
× × × ××
Maintain clock suspend
Notes 1. Self refresh can be entered only from the all banks idle state. Power down can be entered only from all
banks idle or row active state.
2. Must be legal command as defined in Operative Command Table.
Remark H = High level, L = Low level, × = High or Low level (Don't care)
Data Sheet E0149N10
19