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:
Dec. 08, 2009
Filed:
Mar. 11, 2008
Yasuhiko Taito, Tokyo, JP;
Naoki Otani, Tokyo, JP;
Tomohisa Iba, Itami, JP;
Tsukasa Oishi, Tokyo, JP;
Yasuhiko Taito, Tokyo, JP;
Naoki Otani, Tokyo, JP;
Tomohisa Iba, Itami, JP;
Tsukasa Oishi, Tokyo, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
With this flash memory, because a plurality of memory blocks are formed on a surface of a single P-type well, a layout area can be made small. Further, when erasing data for a memory block to be erased, a voltage of the P-type well is applied to all word lines of a memory block to be not erased. Consequently, the voltage of the P-type well and the voltage of all word lines of the memory block to be not erased change at the same time. With this, it is possible to prevent a threshold voltage for the memory block to be not erased from changing.