The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 21, 2014
Filed:
Sep. 29, 2010
Andrew W. Lai, Fremont, CA (US);
Andrew W. Lai, Fremont, CA (US);
Xilinx, Inc., San Jose, CA (US);
Abstract
In one embodiment a circuit for testing delays is provided. A test signal generator circuit toggles a plurality of output signals 1 through N in sequential order, separating the toggles by a delay period. Each output signal is coupled to an input of a respective one of a plurality of delay circuits. A phase detector circuit is coupled to the delay circuits and is configured to determine the order in which signals output from delay circuits X−1, X, and X+1 are toggled for each delay circuit X. In response to the output signals being toggled in the order X−1 followed by X followed by X+1, the phase comparator circuit is configured to output a first signal indicating correct operation. Otherwise, the phase comparator circuit is configured to output a second signal indicating incorrect operation.