A system, method and apparatus for tuning an internal oscillator to a desired frequency F1 is shown and uses an RC delay element that comprises a resistor, a capacitor and a comparator. The method includes receiving a clock signal from an oscillator to be tuned, triggering charging of the RC delay element, and N clock cycles after triggering the charging, the method determines whether the charge on the precision RC delay element is higher than or lower than a reference voltage. Correction to the clock frequency is based on the results.