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:
Jun. 12, 2007
Filed:
May. 05, 2005
Laung-terng (L.-t.) Wang, Sunnyvale, CA (US);
Khader S. Abdel-hafez, San Francisco, CA (US);
Boryau (Jack) Sheu, San Jose, CA (US);
Shianling Wu, Princeton Junction, NJ (US);
Laung-Terng (L.-T.) Wang, Sunnyvale, CA (US);
Khader S. Abdel-Hafez, San Francisco, CA (US);
Boryau (Jack) Sheu, San Jose, CA (US);
Shianling Wu, Princeton Junction, NJ (US);
Syntest Technologies, Inc., Sunnyvale, CA (US);
Abstract
A multi-level 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 scan-based integrated circuit contains one or more scan chains, each scan chain including one or more scan cells coupled in series. Two or more decompressors are embedded between N compressed scan inputs and M scan chains, where N<M, to broadcast compressed scan data patterns driven through the N compressed scan inputs into decompressed scan data patterns stored in the M scan chains. The multi-level scan compression approach allows to speed up the shift-in/shift-out operation during decompression using two or more decompressors separated by intermediate scan chains. Two or more compressors are separated by intermediate scan chains to speed up the shift-in/shift-out operation during compression.