Conclusions

The presented document briefly prensents the design for an FPGA implementation of a fully figital CDR.

The design is intended has proven to work with rates up to 250 Mbps. At such data rate, a possible implementation would be on the Global Control Unit (GCU) board of the JUNO experiment.

JUNO is a neutrino physics experiment, under development, where a big liquid scintillator detector will be read by about 20‘000 large PMTs. Very close to the PMTs, underwater, the analogue signals are digitized, analyzed and stored in the GCU’s FPGA.

Each GCU looks at three PMTs and, elaborating their data, a primitive trigger is generated. The trigger is then sent to the higher lever electronics, via a synchronous link, for a global trigger validation. In case the validation is positive, the same link is used to send back its timestamp. When received, the GCU sends the related waveform to the DAQ via Ethernet.

A CDR is needed to decode the synchronous link messages, which presents a data rate of 125 Mbps. This would be beneficial in terms of cost reduction.