Patent ID: 7907021

Claim:
A two-step VCO calibration method, comprising the steps of: power-on calibration, used to provide a coarse VCO tuning, said power-on calibration being triggered by one control signal, then waiting a period for all channels to turn on and settle down, said power-on calibration comprising; binary search, used to locate a first one channel; storing a result of said binary search to a channel register; judging whether storing all the channels, if false, then going to binary search to locate the other channel; wherein said channel or channels have 9 bits; wherein said binary search locating said first one channel, comprising: counting a feed-back divided clock; using the counting result to decide calibration bits until first 5 correct bits found to locate the first channel; wherein said judging whether storing all the channels, if true, then said power-on calibration ends and system finally enters into an idle state; real-time calibration, used to provide a fine VCO tuning according to loaded result of said power-on calibration, said real-time calibration being triggered by said one control signal when system is ready to transmit/receive data packets, then waiting a period for all the channels to turn on and settle down, said real-time calibration comprising: loading the power-on calibration result from the channel register according to a second channel setting; binary search, used to locate said second channel; wherein said binary search locating said second channel comprising: counting the feed-back divided clock; using the counting result to decide the calibration bits until last 4 correct bits found to locate said second channel.