Methods include receiving a pair of input clock signals; utilizing a stratum clock state machine to control a multiplexer; utilizing the multiplexer to switch an input of a main clock between each of the pair of input clock signals; inducing a phase build-out activity; and transmitting an output clock...http://www.google.fr/patents/US6765424?utm_source=gb-gplus-shareBrevet US6765424 - Stratum clock state machine multiplexer switching
