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:
Jul. 01, 2003
Filed:
Jul. 01, 1999
Hisaya Mori, Hyogo, JP;
Teruhiko Funakura, Tokyo, JP;
Other;
Abstract
A semiconductor test apparatus and method for performing a test on a nonvolatile semiconductor memory such as a flash memory while preventing excessive erasing with reliability. In each erase operation, all addresses are scanned to fetch an error address and error data into a catch memory. Then, on the basis of error information (error address and error data), a rewrite operation is performed to write data on all memory cells. The write data varies according to a comparison result between an address signal and an error address signal. If they disagree, a “0” is written on a memory cell at the address. If they agree, a “0” is written on a “pass” memory cell and a “1” is virtually written on a fail memory cell.