W942508CH Datasheet, PDF (16/47 Pages) Winbond – 8M x 4 BANKS x 8 BIT DDR SDRAM

W942508CH
8.2 Function Truth Table
(Note 1)
CURRENT
STATE
CS RAS CAS WE
ADDRESS
COMMAND
ACTION
Idle
H X X XX
DSL
Nop
L H H XX
NOP/BST
Nop
L H L H BS, CA, A10 READ/READA ILLEGAL
L H L L BS, CA, A10 WRIT/WRITA ILLEGAL
L L H H BS, RA
ACT
Row activating
L L H L BS, A10
PRE/PREA
Nop
L L L HX
AREF/SELF Refresh or Self refresh
L L L L Op-Code
MRS/EMRS
Mode register accessing
Row Active H X X X X
DSL
Nop
L H H XX
NOP/BST
Nop
L H L H BS, CA, A10 READ/READA Begin read: Determine AP
L H L L BS, CA, A10 WRIT/WRITA Begin write: Determine AP
L L H H BS, RA
ACT
ILLEGAL
L L H L BS, A10
PRE/PREA
Precharge
L L L HX
AREF/SELF ILLEGAL
L L L L Op-Code
MRS/EMRS ILLEGAL
Read
H X X XX
DSL
Continue burst to end
L H H HX
NOP
Continue burst to end
L H H LX
BST
Burst stop
L H L H BS, CA, A10 READ/READA Term burst, new read: Determine AP
L H L L BS, CA, A10 WRIT/WRITA ILLEGAL
L L H H BS, RA
ACT
ILLEGAL
L L H L BS, A10
PRE/PREA
Term burst, precharging
L L L HX
AREF/SELF ILLEGAL
L L L L Op-Code
MRS/EMRS ILLEGAL
Write
H X X XX
DSL
Continue burst to end
L H H HX
NOP
Continue burst to end
L H H LX
BST
ILLEGAL
L H L H BS, CA, A10 READ/READA Term burst, start read: Determine AP
L H L L BS, CA, A10 WRIT/WRITA Term burst, start read: Determine AP
L L H H BS, RA
ACT
ILLEGAL
L L H L BS, A10
PRE/PREA
Term burst. precharging
L L L HX
AREF/SELF ILLEGAL
L L L L Op-Code
MRS/EMRS ILLEGAL
NOTES
3
3
2
2
4
4
3
5
6
3
6, 7
6
3
8
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