Patent ID: 7272078

Claim:
A method of ascertaining a representative measurement that is indicative of a relative oscillation speed of a reference clock during a representative calibration period, wherein the reference clock generates a reference clock signal, and wherein a known number of cycles of a signal generated by a non-reference clock span the representative calibration period, the method comprising: defining a plurality of calibration periods including a first calibration period and a second calibration period; causing the first calibration period to begin at a first start time, wherein a first time offset value is equal to a difference between the first start time and a transition point of the reference clock signal within the first calibration period; causing the second calibration period to begin at a second start time, wherein a second time offset value is equal to a difference between the second start time and a transition point of the reference clock signal within the second calibration period, and wherein the first time offset value is different from the second time offset value; generating a plurality of measurements by, for each one of the plurality of calibration periods, ascertaining a characteristic that is indicative of the relative oscillation speed of the reference clock during said one of the plurality of calibration periods; using the plurality of measurements to ascertain an average measurement value; and using the average measurement value as the representative measurement that is indicative of the relative oscillation speed of the reference clock during the representative calibration period.