Patent ID: 6107841
Filing Date: 2000-08-22
Classification: G06F

Abstract:
A clock switching apparatus for switching a clock source from among one or more asynchronous clock sources, the apparatus comprising:means for selecting an asynchronous clock source from among said one or more asynchronous clock sources;multiplexor means capable of receiving one selected clock source and outputting a corresponding system clock output;first switch means responsive to a switching control signal and a system clock output corresponding to a first asynchronous clock source for generating a first control signal, said selecting means responsive to said first control signal for coupling a selected second asynchronous clock source signal into said multiplexor means, and said multiplexor means further responsive to said first control signal for said maintaining said system clock output at a constant level; and,second switch means responsive to a second control signal and said coupled second asynchronous clock source signal to provide a reset signal input to said first switching means for resetting said first control signal,wherein said multiplexor means is responsive to said reset first control signal to provide a system clock output corresponding to said second asynchronous clock source.