Electronic digital logic circuitry – Multifunctional or programmable – Array
Reexamination Certificate
2005-10-18
2005-10-18
Tan, Vibol (Department: 2819)
Electronic digital logic circuitry
Multifunctional or programmable
Array
C326S038000, C326S105000
Reexamination Certificate
active
06956399
ABSTRACT:
A lookup table (LUT) circuit comprises a multiplexer circuit having two modes. In a first mode, the multiplexer circuit functions as a standard multiplexer. In a second mode, the multiplexer circuit selects two or more stored values, where the two or more stored values have the same logical value. Thus, in the second mode the delay through the multiplexer circuit is reduced. In a PLD embodiment, two select terminals of the multiplexer are coupled to two different signal lines. When both signal lines are used, the multiplexer circuit is placed into the first mode. When only one of the signal lines is used, the multiplexer circuit is placed into the second mode, a value on the unused signal line is ignored, and two stored values are provided to the output terminal. Thus, the multiplexer circuit has a reduced path delay when one of the two signal lines is unused.
REFERENCES:
patent: 6505337 (2003-01-01), Wittig et al.
patent: 6621296 (2003-09-01), Carberry et al.
patent: 6621298 (2003-09-01), Agrawal et al.
U.S. Appl. No. 09/783,821, filed Feb. 14, 2001, Carmichael et al.
U.S. Appl. No. 10/603,734, filed Jun. 21, 2003, Keller et al.
U.S. Appl. No. 10/768, 304, filed Jan. 29, 2004, Keller et al.
Phil Brinkley, Carl Carmichael; XAPP181 (v.1.0); “SEU Mitigation Design Techniques for the XQR4000XL”; Mar. 15, 2000; available from Xilinx, Inc., 2100 Logic Drive, San Jose, CA 95124 or http//www.xilinx.com.; pp. 1-14.
Cartier Lois D.
Tan Vibol
Xilinx , Inc.
LandOfFree
High-speed lookup table circuits and methods for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High-speed lookup table circuits and methods for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High-speed lookup table circuits and methods for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3437816