Patent ID: 7581132
Filing Date: 2009-08-25
Classification: G06F

Abstract:
1. A method for configuring a clock system for a microcontroller, the method comprising the steps of: providing a main oscillator; providing a phase locked loop that includes an oscillator; loading at least one configuration bit into at least one configuration register of the phase locked loop; using the oscillator of the phase locked loop operating in open loop mode as a backup oscillator; activating the main oscillator and the backup oscillator in reset mode; generating a clock signal from the backup oscillator; applying the clock signal that is generated from the backup oscillator to the microcontroller so as to start the microcontroller; and after the main oscillator generates a stabilized signal, applying the stabilized signal that is generated by main oscillator to the microcontroller so as to switch from the backup oscillator to the main oscillator to generate the clock signal for the microcontroller.