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:
Dec. 28, 2004
Filed:
Aug. 08, 2001
Applicant:
Inventors:
Makoto Tabata, Tokyo, JP;
Noboru Okino, Tokyo, JP;
Assignee:
Advantest Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11C 2/900 ;
U.S. Cl.
CPC ...
G11C 2/900 ;
Abstract
A memory block is subject to an erasure operation by a batch operation. Subsequently, a read-out test is conducted upon the memory block to count the number of unerased memory cells. If the count F is equal to or greater than a given number T , a plurality of erasure operations are conducted consecutively next. If F <T , a single erasure operation is conducted next, subsequently followed by a read-out test. The erasure operations and the read-out tests are repeated.