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. 13, 1996
Filed:
Oct. 13, 1994
George Nakane, Nara, JP;
Toshio Mukunoki, Takatsuki, JP;
Nobuyuki Moriwaki, Kyoto, JP;
Tatsumi Sumi, Mishima-gun, JP;
Hiroshige Hirano, Nara, JP;
Tetsuji Nakakuma, Takatsuki, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
The life of a semiconductor memory device can be prolonged by using a plurality of memory cells and decreasing the stress applied to the dielectric film of the memory cells storing a data value '1.' This is achieved in the present invention by decreasing the number of rewritings required to retain stored data. Specifically, the present invention utilizes a reverse and rewrite means to reverse and rewrite data back into memory cells after being read, memory means for memorizing a signal indicating whether the currently stored data is in a reversed state, and judging means for judging whether the data should be reversely output.