Run Control Communication for the Upgrade of the ATLAS Muon-to-Central-Trigger-Processor Interface (MUCTPI)

The Muon-to-Central Trigger Processor Interface (MUCTPI) of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN will be upgraded to an ATCA blade system for Run 3. The new design requires development of new communication models for control, configuration and monitoring. A System-on-Chip (SoC) with a programmable logic part and a processor part will be used for communication to the run control system and to the MUCTPI processing FPGAs. Different approaches have been compared. First, we tried an available UDP-based implementation in firmware for the programmable logic. Although this approach works as expected, it does not provide any flexibility to extend the functionality to more complex operations, e.g. for serial protocols. Second, we used the SoC processor with an embedded Linux operating system and an application-specific software written in C++ using a TCP remote-procedure-call approach. The software is built and maintained using the Yocto/OpenEmbedded framework. This approach was successfully used to test and validate the MUCTPI prototype. A third approach under investigation is the option of porting the ATLAS run control software directly to the embedded Linux.