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:
Aug. 14, 2007
Filed:
Sep. 22, 2005
Atsushi Nakayama, Kawasaki, JP;
Toshimasa Namekawa, Tokyo, JP;
Hiroaki Nakano, Yokohama, JP;
Hiroshi Ito, Yokohama, JP;
Osamu Wada, Yokohama, JP;
Atsushi Nakayama, Kawasaki, JP;
Toshimasa Namekawa, Tokyo, JP;
Hiroaki Nakano, Yokohama, JP;
Hiroshi Ito, Yokohama, JP;
Osamu Wada, Yokohama, JP;
Kabushiki Kaisha Toshiba, Tokyo, JP;
Abstract
A nonvolatile semiconductor memory device comprising a storage element which is programmed with information by varying electrical properties irreversibly, a selection switch connected in series to the storage element, a protection element connected in parallel to the storage element to protect the storage element from irreversible variations of electrical properties when the storage element is unprogrammed, a first activation circuit which activates the selection switch, a second activation circuit which activates the protection element in complement with the first activation circuit in normal mode, and a test circuit which conducts a test on the storage element while the second activation circuit is activating the protection element together with the first activation circuit in test mode.