US Patent 7405604 Variable delay clock circuit and method thereof

An apparatus for generating an output clock is disclosed. The apparatus comprises: N variable offset clock circuits for receiving N input clocks and for generating N intermediate clocks having N phase offsets controlled by N intermediate signals, respectively, where N>1; a clock multiplexer for selecting one of the N intermediate clocks as the output clock according to a finite-state signal having N possible states; and a finite-state-machine for receiving a control signal and the N intermediate clocks and for generating the finite-state signal and the N intermediate signals.