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:
Aug. 20, 2002
Filed:
Apr. 11, 2001
Applicant:
Inventor:
Siuki Chan, Cupertino, CA (US);
Assignee:
Xilinx, Inc., San Jose, CA (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K 1/900 ; H03K 1/9177 ;
U.S. Cl.
CPC ...
H03K 1/900 ; H03K 1/9177 ;
Abstract
A test configuration for a programmable logic device (PLD) measures and stores the relative signal-propagation delays of a pair of signal paths extending into the PLD from PLD input pins. The PLD is configured to instantiate a ring oscillator that selectively includes either signal path in the ring. The oscillator exhibits a first oscillation period when the oscillator includes the first signal path, and exhibits a second oscillation period when the oscillator includes the second signal path. The difference between the first and second periods provides a measure of the difference between the signal propagation delays of the two paths of interest.