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:
Apr. 10, 2007
Filed:
Oct. 28, 2005
Yoshiaki Okuyama, Kawasaki, JP;
Yoshiaki Okuyama, Kawasaki, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
An oscillator generates a refresh request signal periodically. A storing circuit changes a stored value by a predetermined value in response to the refresh request signal and returns the stored value by one in response to a refresh operation. A store control circuit, when a state detecting circuit detects a change of an operational state of a semiconductor memory, increases or decreases the predetermined value which the storing circuit uses. A refresh decision circuit outputs refresh signals of a number corresponding to the stored value until the stored value returns to an initial value. This makes it possible to change the frequency of the refresh operations according to a change of the operational state without changing an oscillation cycle of the oscillator. Without unnecessary oscillation of the oscillator, it is possible to decrease a standby current of the semiconductor memory.