Pure, unadulterated inventiveness III: The digital trigger system
Implementing a digital trigger system was rather difficult. This is because the ASIC has to handle a massive stream of data after A/D conversion. The volume of this stream is roughly equivalent to five DVDs worth of data every second. The digital trigger has to look at this data stream in realtime and then trigger at the right moment. With a 500 MHz clock, that means checking and correctly evaluating 20 samples every 2 nanoseconds. To avoid the problem of a mismatch between an analog trigger and the digital data path, the right algorithms have to be used. High speeds were achieved, because there is no need to switch domains and the rearm time that temporarily blinds systems with analog triggers is eliminated.
