A method and apparatus are disclosed for recovering data and clock information from high speed self-clocking data streams at rates of up to approximately 50 Mbps. The self-clocking data stream has a predetermined bit period and two voltage levels with negative-going and positive-going voltage level transitions....http://www.google.com/patents/US4578799?utm_source=gb-gplus-sharePatent US4578799 - Method and apparatus for recovering data and clock information from a self-clocking data stream
