Abstract: An electronic ignition and engine management system with anti-lockup and anti-kickback features for use in an internal combustion marine engine wherein the engine's operating speed is measured and appropriate ignition advance timing values are determined from the operating speed. An ignition pulse is generated at the ignition advances unless the engine is in a startup mode, or below a predetermined startup threshold speed. During startup mode, ignition pulses are generated at or top dead center to avoid overadvanced firing conditions and thus prevent engine lockup and kickback.

Abstract: A circuit for signal generation and synchronization is disclosed for a ring network in which a number of stations communicate with each other. The circuit, which is provided at each station in the ring, includes a phase locked loop which loosely couples the transmit and receive clocks of each station during a repeater mode of operation. During a transmit mode the receive and transmit clocks are de-coupled so that phase delay around the ring does not degrade the transmit clock each time a transmission is initiated. The circuit includes logic gates for detecting the transmission of a token, means for generating a token and means for jam syncing the transmit and receive clocks to detect transistions in the incoming data during the repeater mode and after a token has been generated at the end of the transmit mode.