ON-LINE CALIBRATION METHOD AND DEVICE THEREFOR OF UNIVERSAL SERIAL BUS (USB) SYSTEM

摘要

PROBLEM TO BE SOLVED: To simultaneously refer to termination resistance characteristics of a USB host and a device and to improve mutual adaptability between USB apparatuses.

SOLUTION: An on-line calibration method applied to a USB system includes the steps of: providing a plurality of pairs of chirp signals; applying electric power to a termination resistance of the device and a termination resistance of the host connected thereto and varying levels of the chirp signals before detecting the chirp signals and sending a predetermined number of chirp signals; detecting level changes of the chirp signals having been varied on nodes; and keeping the levels of the chirp signals having been varied within a predetermined range by performing on-line calibration based upon the level changes.

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