Patent ID: 7334149

Claim:
A clock board for a redundant clock distribution system, the clock board comprising: a clock synthesizer configured to provide an input clock signal, wherein energy of the input clock signal is substantially concentrated around an input clock signal frequency; and a spread spectrum unit coupled to receive the input clock signal from the clock synthesizer, wherein the spread spectrum unit is configured to frequency modulate the input clock signal, thereby producing an output clock signal, wherein energy of the output clock signal is spread over a range of frequencies, and wherein, when the clock board is operating as a master in a redundant clock distribution system having a master clock board and a slave clock board, the spread spectrum unit is enabled; wherein the clock board is configured to disable the spread spectrum unit when operating as the slave clock board; and wherein the clock board, when operating as the slave clock board, is configured to assume the role of the master responsive to a failure of the master clock board.