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. 15, 2006
Filed:
Dec. 22, 2004
Kunisato Yamaoka, Takatsuki, JP;
Hiroshige Hirano, Nara, JP;
Kunisato Yamaoka, Takatsuki, JP;
Hiroshige Hirano, Nara, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
In a ferro-electric memory including reference cells, if one reference cell is associated with a plurality of normal cells, a period in which 'L' data is written in the reference cell and a period in which 'H' data is written or read out in/from the reference cell are controlled to be shorter than a period in which “L” data is written in each normal cell and a period in which “H” data is written or read out in/from each normal cell, respectively. In this manner, stress applied to the reference cell is reduced and, even if writing or reading is repeatedly performed on the normal cells, the reliability of the reference cell is enhanced and deterioration in characteristics of the reference cell due to repetitive rewriting of data is suppressed.