White Electronic Designs
CLOCK ENABLE (CKE0) TRUTH TABLE
CKE
Current State
Previous
Cycle
H
L
L
L
L
L
L
H
L
L
H
H
H
H
H
H
H
H
H
H
H
L
H
H
L
L
Current
Cycle
X
H
H
H
H
H
L
X
H
H
X
H
H
H
H
H
L
L
L
L
H
X
H
L
H
L
CE#
X
H
L
L
L
L
X
X
H
L
L
H
L
L
L
L
H
L
L
L
L
X
X
X
X
X
RAS#
X
X
H
H
H
L
X
X
X
X
H
X
H
L
L
L
X
H
L
L
L
X
X
X
X
X
Command
CAS#
X
X
H
H
L
X
X
X
X
X
L
X
X
H
L
L
X
X
H
L
L
X
X
X
X
X
WE#
X
X
H
L
X
X
X
X
X
X
L
X
X
X
H
L
X
X
X
H
L
X
X
X
X
X
BA0-1
X
X
X
X
X
X
X
X
X
X
X
A10-11 Action
X
X
X
X
X
X
X
X
X
X
WED3DL3216V
Notes
1
Self Refresh
Power Down
INVALID
Exit Self Refresh with Device Deselect
Exit Self Refresh with No Operation
ILLEGAL
ILLEGAL
ILLEGAL
Maintain Self Refresh
INVALID
Power Down Mode exit, all banks idle
ILLEGAL
Maintain Power Down Mode
Refer to the Idle State section of the
Current State Truth Table
2
1
2
2
2
3
X
X
OP Code
CBR Refresh
Mode Register Set
Refer to the Idle State section of the
Current State Truth Table
4
3
4
4
All Banks Idle
X
X
OP Code
X
X
X
X
X
X
X
X
X
X
Any State
other than
listed above
Entry Self Refresh
Mode Register Set
Power Down
Refer to the Operations in the Current
State Truth Table
Begin Clock Suspend next cycle
Exit Clock Suspend next cycle
Maintain Clock Suspend
5
NOTES:
1.
For the given Current State CKE must be low in the previous cycle.
2.
When CKE has a low to high transition, the clock and other inputs are re-enabled asynchronously. The minimum setup time for CKE (t
CKS
)
must be satisfied before any command other than Exit is issued.
3.
The address inputs (A12-0) depend on the command that is issued. See the Idle State section of the Current State Truth Table for more
information.
4.
The Power Down Mode, Self Refresh Mode, and the Mode Register Set can only be entered from the all banks idle state.
5.
Must be a legal command as defined in the Current State Truth Table.
White Electronic Designs Corp. reserves the right to change products or specifications without notice.
January, 2004
Rev. 0
7
White Electronic Designs Corporation • (602) 437-1520 • www.wedc.com
WEDC [ WHITE ELECTRONIC DESIGNS CORPORATION ]
