WED9LC6816V
White Electronic Designs
SDRAM Current State Truth Table (cont.)
Command
Current State
Action
Notes
SDCE#
SDRAS #
SDCAS#
SDWE#
A12 & A13 (BA)
A11-A0
Description
Mode Register Set
Auto or Self Refresh
Precharge
L
L
L
L
L
L
L
L
L
L
L
L
L
H
L
OP Code
ILLEGAL
ILLEGAL
X
X
X
L
H
H
L
X
Row Address
Column
Column
X
ILLEGAL
2
2
L
H
L
BA
BA
BA
X
Bank Activate
Write
ILLEGAL
Write with Auto
Precharge
H
H
H
H
ILLEGAL
L
H
L
Read
ILLEGAL
H
H
Burst Termination
No Operation
ILLEGAL
H
X
X
Continue the Burst
H
X
X
X
X
X
Device Deselect
Continue the Burst
L
L
L
L
L
L
L
L
L
L
L
H
L
OP Code
Mode Register Set
Auto or Self Refresh
Precharge
ILLEGAL
ILLEGAL
X
X
H
H
X
X
No Operation; Bank(s) idle after tRP
ILLEGAL
H
BA
Row Address
Bank Activate
2
2
L
H
L
L
BA
Column
Write w/o Precharge
ILLEGAL
Precharging
L
L
L
H
H
H
L
H
H
H
L
BA
X
Column
Read w/o Precharge
Burst Termination
No Operation
ILLEGAL
20
X
X
No Operation; Bank(s) idle after tRP
No Operation; Bank(s) idle after tRP
H
X
H
X
X
X
X
X
Device Deselect
No Operation; Bank(s) idle after tRP
L
L
L
L
L
L
L
L
H
L
L
L
L
L
H
L
OP Code
OP Code
OP Code
Mode Register Set
Auto or Self Refresh
Precharge
ILLEGAL
ILLEGAL
X
X
X
L
H
H
L
X
ILLEGAL
2
2
2
2
L
H
L
BA
BA
BA
X
Row Address
Bank Activate
Write
ILLEGAL
Row Activating
H
H
H
H
X
Column
ILLEGAL
L
H
L
Column
Read
ILLEGAL
H
H
X
X
X
X
Burst Termination
No Operation
Device Deselect
No Operation; Row active after tRCD
No Operation; Row active after tRCD
No Operation; Row active after tRCD
H
X
X
X
L
L
L
L
Mode Register Set
ILLEGAL
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
L
L
L
L
H
H
L
H
L
X
X
X
Auto or Self Refresh
Precharge
ILLEGAL
ILLEGAL
X
2
2
6
6
L
H
L
BA
BA
BA
X
Row Address
Bank Activate
Write
ILLEGAL
Write
Recovering
H
H
H
H
X
L
Column
Start Write; Determine if Auto Precharge
Start Read; Determine if Auto Precharge
No Operation; Precharge after tDPL
No Operation; Precharge after tDPL
No Operation; Precharge after tDPL
ILLEGAL
L
H
L
Column
Read
H
H
X
L
X
X
X
Burst Termination
No Operation
Device Deselect
Mode Register Set
Auto or Self Refresh
Precharge
H
X
L
X
X
L
L
H
L
X
X
X
ILLEGAL
L
H
H
L
X
Row Address
Column
Column
X
ILLEGAL
2
L
H
L
BA
BA
BA
X
Bank Activate
Write
ILLEGAL
2
With Recovering
with Auto
Precharging
H
H
H
H
ILLEGAL
2,6
2,6
L
H
L
Read
ILLEGAL
H
H
Burst Termination
No Operation
No Operation; Precharge after tDPL
No Operation; Precharge after tDPL
H
X
X
H
X
X
X
X
X
Device Deselect
No Operation; Precharge after tDPL
Contact factory for ordering information.
White Electronic Designs Corp. reserves the right to change products or specifications without notice.
September, 2003
Rev. 1
12
White Electronic Designs Corporation • (602) 437-1520 • www.wedc.com
WEDC [ WHITE ELECTRONIC DESIGNS CORPORATION ]
