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:
Oct. 27, 2015
Filed:
Sep. 05, 2014
Kabushiki Kaisha Toshiba, Minato-ku, JP;
Naoaki Kokubun, Yokohama, JP;
Osamu Torii, Setagaya, JP;
Kohsuke Harada, Yokohama, JP;
Riki Suzuki, Yokohama, JP;
Kabushiki Kaisha Toshiba, Minato-ku, JP;
Abstract
According to one embodiment, a storage device comprises a nonvolatile memory and a memory controller that performs reading and writing data from and into the nonvolatile memory. A number, not being 2, of threshold areas can be set in the memory cells of the nonvolatile memory. The memory controller performs first writing based on first data value assignment, which sets 2data values to correspond to 2threshold areas, in first-time writing into a first memory cell of the nonvolatile memory and performs second writing on the first memory cell after the first writing without erasing data based on second data value assignment, which sets 2data values to correspond to 2threshold areas including threshold areas not used in the first data value assignment.