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Title: I/O impedance controller

Abstract

There is disclosed apparatus and apparatus for impedance control to provide for controlling the impedance of a communication circuit using an all-digital impedance control circuit wherein one or more control bits are used to tune the output impedance. In one example embodiment, the impedance control circuit is fabricated using circuit components found in a standard macro library of a computer aided design system. According to another example embodiment, there is provided a control for an output driver on an integrated circuit ("IC") device to provide for forming a resistor divider network with the output driver and a resistor off the IC device so that the divider network produces an output voltage, comparing the output voltage of the divider network with a reference voltage, and adjusting the output impedance of the output driver to attempt to match the output voltage of the divider network and the reference voltage. Also disclosed is over-sampling the divider network voltage, storing the results of the over sampling, repeating the over-sampling and storing, averaging the results of multiple over sampling operations, controlling the impedance with a plurality of bits forming a word, and updating the value of the word by only one least significant bit atmore » a time.« less

Inventors:
; ;
Issue Date:
Research Org.:
Silicon Graphics, Inc., Mountain View, CA, (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1174757
Patent Number(s):
6,703,908
Application Number:
09/619,724
Assignee:
Silicon Graphics, Inc. OSTI
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
42 ENGINEERING; 30 DIRECT ENERGY CONVERSION

Citation Formats

Ruesch, Rodney, Jenkins, Philip N., and Ma, Nan. I/O impedance controller. United States: N. p., 2004. Web.
Ruesch, Rodney, Jenkins, Philip N., & Ma, Nan. I/O impedance controller. United States.
Ruesch, Rodney, Jenkins, Philip N., and Ma, Nan. Tue . "I/O impedance controller". United States. https://www.osti.gov/servlets/purl/1174757.
@article{osti_1174757,
title = {I/O impedance controller},
author = {Ruesch, Rodney and Jenkins, Philip N. and Ma, Nan},
abstractNote = {There is disclosed apparatus and apparatus for impedance control to provide for controlling the impedance of a communication circuit using an all-digital impedance control circuit wherein one or more control bits are used to tune the output impedance. In one example embodiment, the impedance control circuit is fabricated using circuit components found in a standard macro library of a computer aided design system. According to another example embodiment, there is provided a control for an output driver on an integrated circuit ("IC") device to provide for forming a resistor divider network with the output driver and a resistor off the IC device so that the divider network produces an output voltage, comparing the output voltage of the divider network with a reference voltage, and adjusting the output impedance of the output driver to attempt to match the output voltage of the divider network and the reference voltage. Also disclosed is over-sampling the divider network voltage, storing the results of the over sampling, repeating the over-sampling and storing, averaging the results of multiple over sampling operations, controlling the impedance with a plurality of bits forming a word, and updating the value of the word by only one least significant bit at a time.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2004},
month = {3}
}

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