US Patent 7944241 Circuit for glitchless switching between asynchronous clocks

A circuit for glitchless switching between asynchronous clocks includes a select circuit and enable circuits. The select circuit receives a selection signal for selecting one of the clock input signals and to generate enabling signals for activating the corresponding enable circuits on the basis of the current output signal. The feedback logic in the circuit ensures that at any given instance only one of the clock input signals is outputted so as to avoid the formation of glitches. The circuit can be applied to switches between any number of asynchronous clocks.