| 摘要 |
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 signals 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. A set of signal detectors produces output signals of states indicating whether the potential of each conductor has been driven low since the last rising edge of each clock signal pulse, and a programmable decoder supplies a trigger initiating signal on detection of selected patterns of signal detector output signal states. A trigger synchronizer generates the trigger signal of state set according to the current state of the trigger initiating signal on the rising edge of each clock pulse. |
