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:
Feb. 10, 2004
Filed:
Feb. 23, 2001
Brian William Hughes, Fort Collins, CO (US);
Warren Kurt Howlett, Windsor, CO (US);
Hewlett-Packard Development Company, L.P., Houston, TX (US);
Abstract
The present invention incorporates built-in self test and self repair functionality into a semiconductor memory device in which reconfiguration data used to replace faulty memory is stored at the same time testing to identify other faulty memory cells continues. To avoid access contention conflicts to a content addressable memory used to identify rows or groups of rows having faulty memory cells, the built in test function writes test data to each cell at least twice before reading the stored data. By writing twice before reading, contention problems caused by simultaneous updating of the content addressable memory are avoided. That is, even if the content addressable memory is initially unavailable to process address information used to access a memory cell to be tested, repetition of the write process ensure that the data will be properly stored when the memory again becomes available after being updated.