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. 29, 2003
Filed:
Sep. 12, 2001
Applicant:
Inventors:
Katsuyuki Nomura, Hino, JP;
Akihisa Fujimoto, Fussa, JP;
Assignee:
Kabushiki Kaisha Toshiba, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G06F 1/200 ; G11C 1/600 ;
U.S. Cl.
CPC ...
G06F 1/200 ; G11C 1/600 ;
Abstract
A rewritable nonvolatile memory comprises a block usage control table indicating a usage status of each block of the nonvolatile memory. When the data is written, it is determined whether or not the data is correctly written. If it is determined that the data is not correctly written, the block address is stored as a candidate address of a defective block and writing operation is performed for another block. If it is determined that the data is correctly written, the block usage control table is updated such that the usage status of the candidate of a defective block and the present block is changed to a used status.