Implementing Temperature Supervision for the ALICE CRU Card Using the Onboard Microcontroller

We report on the first implementation of the thermal supervisory firmware for the onboard microcontroller on the ALICE CRU card. The Common Readout Unit (CRU) is a custom PCI Express FPGA card developed by “Centre Physique des Particules de Marseille” in collaboration of LHCb and ALICE. While the main effort has been focused on the development of the FPGA firmware that implements all the communication needs, there are several independent design tasks identified to ensure the safe operation of the CRU card under all possible conditions. One such task is to implement a robust local (on-board) temperature monitoring and safeguarding subsystem based on ATmega128 microcontroller. It will autonomously prevent the thermal damage of the card even if the remote HW monitoring and controlling functions (integrated in DCS) failed for any reason. Consequently, our main goal in this project will be implementing the temperature supervision using the onboard microcontroller.