The Trigger Supervisor of the NA48 experiment at CERN SPS

The NA48 experiment aims to measure direct CP violation in the KL0 decays system with an accuracy of 2x10-4. High performances are required of the trigger and acquisition systems. This paper describes the NA48 Trigger Supervisor, a 40 MHz pipelined hardware system which correlates and processes trigger informations from local trigger sources, searching for interesting patterns. The trigger packet include a timestamp information used by the readout systems to retrieve detector data. The design architecture and functionality during 98 data taking are described