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. 18, 2001
Filed:
Dec. 07, 2000
Takamichi Kasai, Kawasaki, JP;
Nozomi Kasai, Kawasaki, JP;
Kabushiki Kaisha Toshiba, , JP;
Abstract
This invention provides a nonvolatile semiconductor memory device capable of avoiding complicatedness of algorithm for normal write operation and a write operation prior to erasing in a memory system in which the distribution of threshold of cells after erasing is adjusted. This nonvolatile semiconductor memory device generates check bits as error correction code according to a check bit generating matrix so formed that in both the normal write operation and the write operation prior to erasing, the factors of “1” of respective rows satisfy the quantity absolutely necessary for generating check bits and the quantity of the factors of “1” is an odd number.