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:
Jan. 01, 2008
Filed:
Sep. 28, 2004
Yasuyuki Fukuda, Yokohama, JP;
Masatsugu Kojima, Yokohama, JP;
Kenichi Imamiya, Tokyo, JP;
Koji Hosono, Yokohama, JP;
Yasuyuki Fukuda, Yokohama, JP;
Masatsugu Kojima, Yokohama, JP;
Kenichi Imamiya, Tokyo, JP;
Koji Hosono, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A non-volatile semiconductor memory device includes: a cell array having electrically rewritable and non-volatile memory cells arranged therein, the cell array being divided into a plurality of blocks, each the block being divided into a plurality of sub-blocks each having one or plural and continuous pages; and a controller for controlling data erasure of the cell array in a way that each the sub-block serves as a unit of data erasure, wherein each the sub-block in the cell array stores the number of data erasure which is renewed by each data erasure, and the number of data erasure is limited for each the sub-block to a permissible maximum value stored in a certain block in the cell array.