A General Purpose Trigger and Readout Board for HADES and FAIR-Experiments

HADES is a running spectrometer installed at GSI, Germany. PANDA and CBM are planned detector systems for the new FAIR facility at GSI. For these detectors, a general-purpose trigger and readout board with on-board DAQ functionality was developed. The original motivation for this project was the implementation of a 128-channel time to digital converter (TDC) with a time resolution of sigma=40 ps based on the HPTDC chip from CERN into a fully fledged data acquisition system. The application of the board is detector independent, includes a 2 Gbit/s optical link and has the option to employ the TDC chips and/or to integrate versatile add-on boards through 16 Gbit/s connectors. The latter one may interface to the front end electronics of other types of detectors. A large FPGA (Xilinx Virtex 4 LX40) and a TigerSharc DSP can be used as on-board resources for trigger and on-line analysis algorithms. Data transfer to mass storage and slow control is done via an ETRAX processor running Linux and a 100 Mbit/s Ethernet interface.