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:
Jun. 22, 2010
Filed:
Dec. 04, 2007
Chiaki Dono, Tokyo, JP;
Yasuji Koshikawa, Tokyo, JP;
Chiaki Dono, Tokyo, JP;
Yasuji Koshikawa, Tokyo, JP;
Elpida Memory, Inc., Tokyo, JP;
Abstract
A semiconductor memory device includes a first refresh cycle changing circuit that changes a refresh cycle according to an auto-refresh mode, without giving influence to a refresh cycle according to a self-refresh mode, and a second refresh cycle changing circuit that changes a refresh cycle according to the self-refresh mode, without giving influence to a refresh cycle according to the auto-refresh mode. In this way, according to the present invention, the refresh cycle according to the auto-refresh mode and the refresh cycle according to the self-refresh mode can be controlled independently. Therefore, refresh operation considering the characteristic of each mode can be executed.