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. 09, 2009
Filed:
Aug. 23, 2007
Hiroyoshi Tomita, Kawasaki, JP;
Hiroyoshi Tomita, Kawasaki, JP;
Fujitsu Microelectronics Limited, Tokyo, JP;
Abstract
A semiconductor memory device includes a timing signal circuit to generate a refresh timing signal comprised of a series of pulses, a refresh address circuit to generate a refresh address in synchronization with each pulse of the refresh timing signal, a pulse selecting circuit to assert a refresh request signal in synchronization with pulses selected from the series of pulses, and a memory core to receive the refresh address and the refresh request signal and to perform a refresh operation with respect to the refresh address in response to assertion of the refresh request signal, wherein arrangement is made to switch between a first operation mode in which the selected pulses are obtained by selecting one pulse out of every predetermined number of pulses from the series of pulses and a second operation mode in which the selected pulses are obtained by selecting consecutive pulses from the series of pulses.