The trigger supervisor of the NA48 experiment at CERN SPS

The NA48 experiment aims to measure direct CP violation in the $K_{L}^{0}$ decays system with an accuracy of $2 \times 10^{-4}$. High performances are required to the trigger and acquisition systems. This paper describes the NA48 Trigger Supervisor, a 40 MHz pipelined hardware system which correlates and processes trigger information 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.