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. 27, 2010
Filed:
Dec. 16, 2008
Kenichi Sakakibara, Tokyo, JP;
Kenichi Sakakibara, Tokyo, JP;
Elpida Memory, Inc., Tokyo, JP;
Abstract
A semiconductor memory device having two refreshment modes of auto-refreshment and partial self-refreshment imposed on memory cells includes a command decoder which detects one of the refreshment modes from an input command, outputs type data which indicates the detected refreshment mode, and outputs a refreshment signal which indicates the start of refreshment; a mode register in which the type data is set; a signal selection circuit which determines whether or not the refreshment signal is to be delayed, in accordance with the type data set in the mode register, and outputs the refreshment signal, which is delayed or not delayed in accordance with the result of the determination, as a refreshment start signal; and a control circuit which reads the type data set in the mode register based when receiving the refreshment start signal, and performs refreshment corresponding to the type data.