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:
Sep. 15, 2009
Filed:
May. 05, 2005
Khader S. Abdel-hafez, San Francisco, CA (US);
Laung-terng (L.-t.) Wang, Sunnyvale, CA (US);
Boryau (Jack) Sheu, San Jose, CA (US);
Shianling Wu, Princeton Junction, NJ (US);
Khader S. Abdel-Hafez, San Francisco, CA (US);
Laung-Terng (L.-T.) Wang, Sunnyvale, CA (US);
Boryau (Jack) Sheu, San Jose, CA (US);
Shianling Wu, Princeton Junction, NJ (US);
Syntest Technologies, Inc., Sunnyvale, CA (US);
Abstract
A pipelined scan compression method and apparatus for reducing test data volume and test application time in a scan-based integrated circuit without reducing the speed of the scan chain operation in scan-test mode or self-test mode. The integrated circuit contains one or more scan chains, each scan chain comprising one or more scan cells coupled in series. A decompressor is embedded between N scan chains and M scan chains, where N<M, to broadcast compressed scan data patterns driven through the N scan chains into decompressed scan data patterns stored in the M scan chains. To speed up the shift-in/shift-out operation during decompression, the decompressor can be further split into two or more pipelined decompressors each placed between two sets of intermediate scan chains. The invention further comprises one or more pipelined compressors to speed up the shift-in/shift-out operation during compression.