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. 28, 2016
Filed:
May. 22, 2015
Ps4 Luxco S.a.r.i., Luxembourg, LU;
Nakaba Kaiwa, Tokyo, JP;
Yutaka Ikeda, Tokyo, JP;
Hiroki Fujisawa, Tokyo, JP;
Tetsuaki Okahiro, Tokyo, JP;
PS4 Luxco S.a.r.l., Luxembourg, LU;
Abstract
A semiconductor device having a circuit that selectively adjusts an impedance of an output buffer. A calibration operation can be performed automatically without issuing a calibration command from a controller. Because a calibration operation to a memory is performed in response to an auto refresh command having been issued for a predetermined number of times, a periodic calibration operation can be secured, and a read operation or a write operation is not requested from a controller during a calibration operation. A start-up circuit activates the calibration circuit when a refresh counter indicates a predetermined value, and prohibits a refresh operation in response to the auto refresh command when the calibration circuit is activated. A temperature detecting circuit may be used to change the frequency of performing a calibration operation.