W981216AH Datasheet, PDF (9/44 Pages) Winbond – 2M x 16 bit x 4 Banks SDRAM

W981216AH
Operation Mode
2M x 16 bit x 4 Banks SDRAM
Fully synchronous operations are performed to latch the commands at the positive edges of CLK. Table 1 shows the truth
table for the operation commands.
Table 1 Truth Table ( note (1) , (2) )
command
A11,
Device state
CKEn-1
CKEn
DQM
BS0,1 A10 _A9-0
CS RA
CAS
WE
Bank Active
Idle
H
x
x
v
v v LLHH
Bank Precharge
Any
H
x
x
v
L x LLHL
Precharge All
Any
H
x
x
x H x LLHL
Write
Active (3)
H
x
x
v
L v LH L L
Write with Autoprecharge
Active (3)
H
x
x
v H v LH L L
Read
Active (3)
H
x
x
v
L v LH L H
Read with Autoprecharge
Active (3)
H
x
x
v H v LH L H
Mode Register Set
Idle
H
x
x
v
v v LL L L
No - Operation
Any
H
x
x
x
x x LHHH
Burst Stop
Active (4)
H
x
x
x
x x LHH L
Device Deselect
Any
H
x
x
x
x x Hx x x
Auto - Refresh
Idle
H
H
x
x
x x LL LH
Self - Refresh Entry
Idle
H
L
x
x
x x LL LH
Self Refresh Exit
idle
L
H
x
x
x x Hx x x
(S.R.)
L
H
x
x
x x LHH x
Clock suspend Mode Entry
Active
H
L
x
x
x x xx x x
Power Down Mode Entry
Idle
H
Active (5)
H
L
x
x
x x Hx x x
L
x
x
x x LHH x
Clock Suspend Mode Exit
Active
L
H
x
x
x x xx x x
Power Down Mode Exit
Any
L
(power down)
L
H
x
x
x x Hx x x
H
x
x
x x LHH x
Data write/Output Enable
Active
H
x
L
x
x x xx x x
Data Write/Output Disable
Active
H
x
H
x
x x xx x x
Notes: (1) v= valid x = Don't care L= Low Level H= High Level
(2) CKEn signal is input level when commands are provided.
(3) These are state of bank designated by BS0, BS1 signals.
(4) Device state is full page burst operation.
(5) Power Down Mode can not be entered in the burst cycle.
When this command asserts in the burst cycle, device state is clock suspend mode.
Revision 1.0
Publication Release Date: March, 1999
-9-