Patent ID: 7250825

Claim:
A method for calibrating an on-chip non-precision oscillator, comprising the steps of: providing an on-chip precision oscillator having a known frequency of operation that is within an acceptable operating tolerance; using the on-chip precision oscillator as a time base; measuring the period of the on-chip non-precision oscillator as a function of the time base; determining from the measured period relative to the frequency of the on-chip precision oscillator the frequency of the non-precision oscillator; determining the difference between the determined frequency of the on-chip non-precision oscillator and a desired operating frequency of the on-chip non-precision oscillator; adjusting the frequency of the on-chip non-precision oscillator via a control input to said non-precision oscillator to minimize the determined difference; and when minimized, fixing the frequency of the non-precision oscillator to operate independent of the on-chip precision oscillator.