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. 24, 2007
Filed:
Mar. 03, 2005
Applicants:
Hajime Sato, Kasugai, JP;
Yuji Nakagawa, Kasugai, JP;
Satoru Kawamoto, Kasugai, JP;
Inventors:
Assignee:
Fujitsu Limited, Kawasaki, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11C 7/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A refresh method for a semiconductor memory device features high noise resistance, lower power consumption, and lower cost. All word lines of one or more memory cell blocks that have not been selected in a self refresh mode are controlled to have a floating potential substantially at ground level. Even when a word line and a bit line are short-circuited, this control prevents destruction of memory cell information, which may be caused by noise, and also prevents generation of leakage current. A fuse, etc., for preventing generation of leakage current is unnecessary, so that lower cost is realized.