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:
Mar. 16, 1999
Filed:
Aug. 15, 1997
James Alan Turnquist, Santa Clara, CA (US);
Leon Lee Chen, Santa Clara, CA (US);
Advantest Corp., Tokyo, JP;
Abstract
A compression and decompression apparatus to be used for transferring test pattern data from a storage device of a host computer to a pattern memory in a semiconductor test system for testing a semiconductor device to decrease the time required for the data transfer. The compression and decompression apparatus includes: a compression means for classifying vector data in the test pattern data into a first group to be compressed to a short code and a second group not to be compressed, and for producing a look-up table showing relationship between the short code and the vector data in the first group; a compressed test pattern file storing compressed test pattern including the short code, data vector in the second group and the look-up table; and a hardware decompression circuit provided in the semiconductor test system or proximity thereto for decompressing the compressed test pattern based on the short code and the relationship shown in the look-up table and for sending decompressed test pattern to the pattern memory in the semiconductor test system.