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:
Sep. 15, 2015
Filed:
Jan. 07, 2014
Kabushiki Kaisha Toshiba, Minato-ku, JP;
Haruki Toda, Yokohama, JP;
KABUSHIKI KAISHA TOSHIBA, Minato-ku, JP;
Abstract
A semiconductor memory device according to the embodiment comprises memory cells each having asymmetrical voltage-current characteristics, wherein the memory cell has a first state, and a second state and a third state of higher resistances than that in the first state, wherein the memory cell, (1) in the second state, makes a transition to the first state on application of a first voltage of the first polarity, (2) in the first state, makes a transition to the second state on application of a second voltage of the second polarity, (3) in the first state, makes a transition to the third state on application of a third voltage of the second polarity (the third voltage<the second voltage), and (4) in the third state, makes a transition to the first state on application of a fourth voltage of the first polarity (the fourth voltage<the first voltage).