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:
Apr. 18, 2006
Filed:
Jun. 28, 2004
Laung-terng (L.-t.) Wang, Sunnyvale, CA (US);
Shun-miin (Sam) Wang, San Jose, CA (US);
Khader S. Abdel-hafez, San Francisco, CA (US);
Xiaoqing Wen, Sunnyvale, CA (US);
Boryau (Jack) Sheu, San Jose, CA (US);
Laung-Terng (L.-T.) Wang, Sunnyvale, CA (US);
Shun-Miin (Sam) Wang, San Jose, CA (US);
Khader S. Abdel-Hafez, San Francisco, CA (US);
Xiaoqing Wen, Sunnyvale, CA (US);
Boryau (Jack) Sheu, San Jose, CA (US);
Syntest Technologies, Inc., Sunnyvale, CA (US);
Abstract
A method and apparatus for selectively masking off unknown ('x') captured scan data in first selected scan cellsfrom propagating through the scan chainsfor test, debug, diagnosis, and yield improvement of a scan-based integrated circuitin a selected scan-test modeor selected self-test mode. The scan-based integrated circuitcontains a plurality of scan chains, a plurality of pattern generators, a plurality of pattern compactors, with each scan chaincomprising multiple scan cellscoupled in series. The method and apparatus further includes an output-mask controllerand an output-mask networkembedded on the scan data input path of second selected scan cells, or a set/reset controller controlling selected set/reset inputs of second selected scan cells. A synthesis method is also proposed for synthesizing the output-mask controllerand the set/reset controller.