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:
Jan. 16, 2007
Filed:
Oct. 21, 2004
Hiroki Ueno, Kokubunji, JP;
Hiroki Ueno, Kokubunji, JP;
Renesas Technology Corp., Tokyo, JP;
Abstract
The present invention provides a semiconductor device that can shorten the initialization cycle of impedance matching of interface buffers and reduce as much as possible affects on other circuits at the time of fine control thereafter. The semiconductor device () includes interface buffers (to) whose internal impedances are controlled by impedance control data and an impedance control circuit () that generates the impedance control data. The impedance control circuit includes a first impedance control mode that initially generates the impedance control data by a binary search and comparison operation resulting from predetermined impedance control steps and sets the impedance control data in the interface buffers, and a second impedance control mode that updates the impedance control data set in the interface buffers by a sequential comparison operation resulting from the predetermined impedance control steps.