A parallel pipelined dataflow trigger processor

A parallel pipelined dataflow trigger processor which is used in Fermilab E789 is described. E789 is an experiment designed to study low-multiplicity decays of particles containing b or c quarks. The processor consists of an upstream vertex processor and a downstream track processor. The algorithms which reconstruct the postulated particle paths and calculate particle origin are implemented via interconnected function-specific hardware modules. The algorithm is directly dependent upon the organization of the modules, the specific arrangement of the intermodule cabling, the on-board wire patch patterns, and, where appropriate, the on-board memory data. The uniqueness of this particular dataflow processor lies in the inclusion of the particle origin calculation. The vertex processor utilizes silicon detector hits to calculate the particle origin and to verify consistency with the downstream track. The downstream tracks are reconstructed by the track processor. The processor provides an indication of the presence of at least one interesting particle pair in the current event by asserting read on its read/skip output. The read assertion is then used as a trigger to capture all of the event´s data for subsequent extensive offline analysis