eorex
EM488M1644VTB
4. Operative Command Table (Continued) (Note 7)
Current
State
/CS /R /C /W
Addr.
Command
Action
H
L
L
L
L
X
H
H
H
H
X
H
H
L
X
H
L
X
DESL
NOP
BST
Nop → Enter row active after tDPL
Nop → Enter row active after tDPL
Nop → Enter row active after tDPL
X
X
H
L
BA/CA/A10
BA/CA/A10
READ/READA Start read, Determine AP
(Note 14)
Write
Recovering
L
WRIT/WRITA
ACT
New write, Determine AP
(Note 9)
ILLEGAL
L
L
L
L
H
H
H
L
BA/RA
(Note 9)
BA, A10
PRE/PALL
ILLEGAL
L
L
H
L
L
L
L
L
L
H
L
X
REF/SELF
MRS
ILLEGAL
ILLEGAL
Op-Code
X
H
H
X
H
H
X
H
L
X
X
X
DESL
NOP
Nop → Enter pre-charge after tDPL
Nop → Enter pre-charge after tDPL
Nop → Enter pre-charge after tDPL
BST
(Note 9, 14)
L
L
L
H
H
L
L
L
H
L
BA/CA/A10
BA/CA/A10
BA/RA
READ/READA
WRIT/WRITA
ACT
ILLEGAL
Write
Recovering
with AP
(Note 9)
ILLEGAL
(Note 9)
H
H
ILLEGAL
L
L
L
H
L
L
L
L
H
L
L
L
L
L
H
L
L
H
L
BA, A10
PRE/PALL
REF/SELF
MRS
ILLEGAL
ILLEGAL
ILLEGAL
X
L
L
Op-Code
X
H
H
L
X
H
L
X
X
X
X
X
X
H
L
X
X
X
X
X
X
X
X
X
DESL
Nop → Enter idle after tRC
Nop → Enter idle after tRC
ILLEGAL
NOP/BST
READ/WRIT
Refreshing
H
L
ACT/PRE/PALL ILLEGAL
REF/SELF/MRS ILLEGAL
L
X
H
H
H
X
H
H
L
DESL
NOP
Nop
Nop
ILLEGAL
ILLEGAL
Mode
Register
Accessing
BST
X
READ/WRIT
ACT/PRE/PALL/
REF/SELF/MRS
L
L
X
X
X
ILLEGAL
Remark H = High level, L = Low level, X = High or Low level (Don't care), AP = Auto Pre-charge
Note 7: All entries assume that CKE was active (High level) during the preceding clock cycle.
Note 8: If all banks are idle, and CKE is inactive (Low level), SDRAM will enter Power down mode.
All input buffers except CKE will be disabled.
Note 9: Illegal to bank in specified states;
Function may be legal in the bank indicated by Bank Address (BA), depending on the state of
that bank.
Note 10: If all banks are idle, and CKE is inactive (Low level), SDRAM will enter Self refresh mode.
All input buffers except CKE will be disabled.
Note 11: Illegal if tRCD is not satisfied.
Note 12: Illegal if tRAS is not satisfied.
Note 13: Must satisfy burst interrupt condition.
Note 14: Must satisfy bus contention, bus turn around, and/or write recovery requirements.
Note 15: Must mask preceding data which don't satisfy tDPL
Note 16: Illegal if tRRD is not satisfied.
.
Dec. 2006
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