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:
Dec. 13, 2005
Filed:
Jan. 07, 2002
Robert Walter Berry, Jr., Round Rock, TX (US);
Michael Timothy Saunders, Round Rock, TX (US);
Robert Walter Berry, Jr., Round Rock, TX (US);
Michael Timothy Saunders, Round Rock, TX (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
In an LSSD/LBIST scan design, AC scan test coverage is enhanced with a scan chain configuration capable of selectively inverting scan-in signals. For example, one or more XOR gates are inserted in the scan chain. The XOR gates is controlled by a control signal preferably coming from a primary input such that original scan-in signals as well as inverted scan-in signals are shifted into the scan chain. The proposed configuration significantly enhances the AC test coverage for a scan chain having adjacent SRLs feeding the same cone of logic by adding a simple logic circuit such as an XOR gate between the adjacent SRLs.