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. 30, 2008
Filed:
May. 02, 2007
Tomohiro Kawakubo, Kawasaki, JP;
Tomohiro Kawakubo, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
A core control circuit outputs operation control signals to a memory core in order to perform refresh operations in response to an internal refresh request from a refresh request generating circuit and an external refresh request. The core control circuit sets the number of memory cells each subjected to the refresh operation in response to the external refresh request larger than the number of memory cells each subjected to the refresh operations in response to the internal refresh request. By relatively increasing the number of memory cells each subjected to the refresh operation in response to one external refresh request, the number of external refresh requests required to refresh all memory cells can be reduced. Accordingly, the frequency with which the external refresh request is supplied to the semiconductor memory can be lowered, which can improve access efficiency.