Patent ID: 9503100
Filing Date: 2016-11-22
CPC Classification: G06F,H03L

Claim Text:
1. A method of tuning an internal oscillator to a desired frequency F1, the method using an RC delay element that comprises a resistor, a capacitor and a comparator, the method comprising: receiving a clock signal from an oscillator to be tuned; triggering charging of the RC delay element; at M clock cycles from triggering the charging, obtaining a first result that indicates whether the voltage on the RC delay element is higher than or lower than a reference voltage; providing corrective feedback to the oscillator based on the first result; after obtaining the first result, charging the capacitor to twice the reference voltage and triggering discharging of the RC delay element; at N clock cycles from triggering the discharging, obtaining a second result that indicates whether the charge on the RC delay element is higher than or lower than the reference voltage; determining whether the first and second results are the same; if the first and second results are not the same, performing the providing; and if the first and second results are the same, adjusting the values of M and N based on the results and refraining from providing corrective feedback to the oscillator.