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:
Apr. 01, 2014
Filed:
Aug. 20, 2012
Noboru Shibata, Kanagawa-ken, JP;
Kazunori Kanebako, Kanagawa-ken, JP;
Noboru Shibata, Kanagawa-ken, JP;
Kazunori Kanebako, Kanagawa-ken, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A semiconductor memory device which includes multi-bit memory cells that store multi-bit data and memory cells that store data of fewer bits then that of the multi-bit data. Thus, the semiconductor memory device includes a plurality of memory cells which store n-bit (where n is a natural number that is equal to or larger than 2) data for one cell. Among the plurality of memory cells, h-bit (h≦n) data is stored in a memory MLC of a first region MLB, and i-bit (i<h) data is stored in a memory SLC of a second region SLB. If the number of rewritings in the memory cells of the second region SLB reaches a prescribed value, the i-bit data is stored in the memory of the first region MLB rather than the memory cells of the second region SLB.