Patent ID: 7221687

Claim:
An apparatus for providing a reference timing signal for use in a synchronous network, the apparatus comprising: a first selector for receiving a first plurality of candidate waveforms and for selecting a first active waveform from said first plurality of candidate waveforms based on a first selection signal; a first signal evaluator for deriving a first evaluation signal based on a characteristic of said first active waveform in comparison to a first threshold; a second selector for receiving a second plurality of candidate waveforms and for selecting a second active waveform from said second plurality of candidate waveforms based on a second selection signal; a second signal evaluator for deriving a second evaluation signal based on a characteristic of said second active waveform in comparison to a second threshold; and a controller for deriving said first selection signal based on said first evaluation signal and on an ordering of said first plurality of candidate waveforms, and for deriving said second selection signal based on said second evaluation signal and on an ordering of said second plurality of candidate waveforms; wherein a change in the first selection signal by said controller is independent of a change in said second selection signal by said controller; and wherein said ordering of said first plurality of candidate waveforms is independent of said ordering of said second plurality of candidate waveforms; a first timing signal generator for deriving a first stabilized signal based on said first active waveform; a second timing signal generator for deriving a second stabilized signal based on said second aactive waveform; and a third selector for selecting a reference timing signal from said first stabilized signal and said second stabilized signal.