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.

Date of Patent:
Apr. 29, 2003

Filed:

Aug. 20, 2001
Applicant:
Inventors:

Nam-Seog Kim, Seoul, KR;

Uk-Rae Cho, Suwon, KR;

Assignee:
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H03K 1/716 ;
U.S. Cl.
CPC ...
H03K 1/716 ;
Abstract

An impedance updating apparatus includes a terminator circuit for receiving and terminating an external input signal, the terminator circuit having an up-terminator and a down-terminator; and an update controller for separately controlling the up-terminator and the down-terminator based on the level of the external input signal. The update controller includes at least one latch for latching impedance codes of a programmable impedance controller, the impedance codes being used for controlling transistors in the up-terminator and down-terminator. The update controller performs updating impedance of the up-terminator, or down-terminator when an up-update enable signal or a down-update enable signal and a level of the external input signal correspond to a predetermined condition. And the update controller performs updating impedance of the up-terminator, or down-terminator in response to a level of the external input signal during set-up or hold time only. An impedance updating method of termination circuit having up/down terminators and a separate update controller for detecting terminator through which minimum current flows in response to level of an external input signal is also provided which includes the steps of: determining signal levels of an external input signal to thereby detect a terminator through which minimum current flows between the up or down terminator; and impedance updating the detected terminator through which minimum current flows.


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