WED3DL644V
White Electronic Designs
CURRENT STATE TRUTH TABLE
Command
A11,
Current State
Action
Notes
CE#
RAS# CAS#
WE#
BA0-1
Description
A10/AP-A0
OP Code
L
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
L
H
L
L
L
L
L
L
L
L
H
L
L
L
L
L
H
L
H
L
H
L
H
X
L
H
L
H
L
H
L
H
X
L
H
L
H
L
H
L
H
X
L
H
L
H
L
H
L
H
X
L
Mode Register Set
Auto or Self Refresh
Precharge
Set the Mode Register
Start Auto or Self Refresh
No Operation
2
2,3
X
X
X
X
L
L
H
H
L
BA
BA
BA
X
X
X
Row Address
Column
Column
Bank Activate
Write w/o Precharge
Read w/o Precharge
Burst Termination
No Operation
Device Deselect
Mode Register Set
Auto or Self Refresh
Precharge
Activate the specified bank and row
ILLEGAL
Idle
H
H
H
H
X
L
4
2
2
L
ILLEGAL
No Operation
No Operation
H
H
X
L
X
X
X
No Operation or Power Down
ILLEGAL
5
OP Code
L
L
X
X
X
X
ILLEGAL
Precharge
ILLEGAL
L
L
H
H
L
6
2
7,8
7,8
BA
BA
BA
X
X
X
Row Address
Column
Column
Bank Activate
Write
Row Active
H
H
H
H
X
L
Start Write; Determine if Auto Precharge
Start Read; Determine if Auto Precharge
No Operation
L
Read
H
H
X
L
X
X
X
Burst Termination
No Operation
Device Deselect
Mode Register Set
Auto or Self Refresh
Precharge
No Operation
No Operation
ILLEGAL
ILLEGAL
OP Code
L
L
X
X
X
X
L
L
H
H
L
Terminate Burst; Start the Precharge
ILLEGAL
BA
BA
BA
X
X
X
Row Address
Column
Column
Bank Activate
Write
4
8,9
8,9
Read
H
H
H
H
X
L
Terminate Burst; Start the Write cycle
Terminate Burst; Start a new Read cycle
Terminate the Burst
Continue the Burst
Continue the Burst
ILLEGAL
ILLEGAL
Terminate Burst; Start the Precharge
ILLEGAL
Terminate Burst; Start a new Write cycle
Terminate Burst; Start the Read cycle
Terminate the Burst
Continue the Burst
Continue the Burst
ILLEGAL
L
Read
H
H
X
L
X
X
X
Burst Termination
No Operation
Device Deselect
Mode Register Set
Auto or Self Refresh
Precharge
OP Code
L
L
X
X
X
X
L
L
H
H
L
BA
BA
BA
X
X
X
Row Address
Column
Column
Bank Activate
Write
4
8,9
8,9
Write
H
H
H
H
X
L
L
Read
H
H
X
L
X
X
X
Burst Termination
No Operation
Device Deselect
Mode Register Set
Auto or Self Refresh
Precharge
OP Code
L
L
H
L
H
L
H
L
H
X
X
X
X
X
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
ILLEGAL
L
L
H
H
L
4
4
BA
BA
BA
X
X
X
Row Address
Column
Column
Bank Activate
Write
Read with
Auto Precharge
H
H
H
H
X
L
Read
H
H
X
X
X
X
Burst Termination
No Operation
Device Deselect
Continue the Burst
Continue the Burst
August 2005
Rev. 6
9
White Electronic Designs Corporation • (602) 437-1520 • www.wedc.com
WEDC [ WHITE ELECTRONIC DESIGNS CORPORATION ]
