EM488M3244VBA-8F Datasheet, PDF (25/33 Pages) List of Unclassifed Manufacturers – 256Mb SDRAM

256Mb SDRAM
4. Operative Command Table
Current
state
/CS /R /C /W Addr.
HX X X
X
LHHX
X
L H L H BA/CA/A10
L H L L BA/CA/A10
Idle
L L H H BA/RA
L L H L BA, A10
LL LH
X
L L L L Op-Code
HX X X
X
LHHX
X
L H L H BA/CA/A10
L H L L BA/CA/A10
Row active
L L H H BA/RA
L L H L BA, A10
LL LH
X
L L L L Op-Code
HX X X
X
LHHH
X
LHHL
X
L H L H BA/CA/A10
Re ad
L L L L BA/CA/A10
L L H H BA/RA
L L H L BA/A10
LL LH
X
L L L L Op-Code
HX X X
X
LHHH
X
LHHL
X
L H L H BA/CA/A10
Wr ite
L L L L BA/CA/A10
L L H H BA/RA
L L H L BA/A10
LL LH
X
L L L L Op-Code
Command
DESL
NOP or BST
REA D/REA DA
WRIT/WRITA
A CT
PRE/PA LL
REF/SELF
MRS
DESL
NOP or BST
REA D/REA DA
WRIT/WRITA
A CT
PRE/PA LL
REF/SELF
MRS
DESL
NOP
BST
REA D/REA DA
WRIT/WRITA
A CT
PRE/PA LL
REF/SELF
MRS
DESL
NOP
BST
REA D/REA DA
WRIT/WRITA
A CT
PRE/PA LL
REF/SELF
MRS
Action
Nop or pow er dow n
Nop or pow er dow n
ILLEGA L
ILLEGA L
Row activating
Nop
Ref resh or self refresh
Mode register accessing
Nop
Nop
Begin read : Determine AP
Begin w rite : Determine AP
ILLEGA L
Precharge
ILLEGA L
ILLEGA L
Continue burst to end  Row active
Continue burst to end  Row active
Burst stop  Row active
Terminate burst, new read : Determine AP
Terminate burst, start w rite : Determine AP
ILLEGA L
Terminate burst, pre-charging
ILLEGA L
ILLEGA L
Continue burst to end  Write recovering
Continue burst to end  Write recovering
Burst stop  Row active
Terminate burst, start read : Determine AP 7, 8
Terminate burst, new w rite : Determine AP 7
ILLEGA L
Terminate burst, pre-charging
ILLEGA L
ILLEGA L
Re m ark H = High level, L = Low level, X = High or Low level (Don't care)
Notes
2
2
3
3
4
5
5
3
6
4
7
7, 8
3
4
7,8
7
3
9
Rev.01
25/33