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. 30, 2019
Filed:
Jan. 04, 2018
Winbond Electronics Corp., Taichung, TW;
Norio Hattori, Kanagawa, JP;
Masaru Yano, Kanagawa, JP;
Winbond Electronics Corp., Taichung, TW;
Abstract
A semiconductor memory device for suppressing a decrease of durability caused by erasure of a block unit or programming of a word unit is provided. A resistance change memoryincludes a memory arrayand a controller. The memory arraystores data by a reversible and nonvolatile variable resistance element. When erasing a selected block of the memory arrayin response to an external erasure command, the controllersets an EF flag indicating the selected block is in an erasure state without changing block data. The controllerfurther includes a reading unit. The reading unit outputs data of a selected word or data indicating the erasure based on the EF flag when reading the selected word of the memory arrayin response to an external reading command.