Abstract: An apparatus for generating a trigger signal in response to a selected pattern of events includes event synchronizers for generating synchronized event signals of states indicating the current state of each event on the falling edge of each pulse of a clock signal. A programmable encoder provides a set of event encoding signals of states set according to selected patterns of synchronized event signal states. A set of bus drivers actively drives the potential of each conductor of a bus high on the falling edge of each clock signal pulse and actively drives the potential of selected conductors of the bus low on the rising edge of each clock signal pulse, the conductors being selected according to the pattern of event indicating signal states generated by the encoder.

Abstract: An apparatus for generating trigger signals responsive to a selected pattern of event detection signals, the apparatus comprising an interim function bus, programmable means to selectively energize conductors of the interim function bus on detection of the selected event detection signal pattern, and programmable means to generate the trigger signal on detection of a selected pattern of interim function bus signals. The generating means are programmed for pattern recognition by binary data appearing on control lines from a shift register, the shift register being loaded by serial data from external control circuits. The apparatus also includes provisions for synchronizing the generation of signal patterns on the interim function bus to a system clock, and for synchronizing the generation of trigger signals to clocks associated with triggerable devices.