Design and Application of a MicroTCA.4-Based Embedded Event Receiver for CSNS-II

[Background] The existing event receivers (EVRs) based on VME or MicroTCA.4 architectures often rely on external controllers for coordinated operations, leading to issues in integration density and cost reduction. Motivated by the critical need for self-reliant core devices for the CSNS-II project, a highly integrated embedded EVR based on an indigenous MicroTCA.4 platform is proposed. [Purpose] This study aims to develop a fully embedded EVR based on a domestically manufactured MicroTCA.4 platform to ensure system autonomy and controllability. [Methods] The proposed EVR utilizes an embedded architecture. In terms of hardware, it employs a Xilinx Zynq SoC to perform real-time decoding of high-speed optical event frames and high-precision trigger generation. On the software side, a tightly integrated architecture combining embedded Linux and EPICS is adopted. A three-layer software stack, comprising a hardware abstraction layer, a record adapter layer, and an application interface layer, is designed to implement a standardized on-board Input/Output Controller (IOC). [Results] Performance tests demonstrate that the RMS synchronization jitter of the output event clock and pulse signals, relative to the RF reference, is less than 15 ps. The embedded EVR has been deployed in the LLRF timing substation of the CSNS-II RCS, achieving continuous online operation for over six months. [Conclusions] The long-term operation validates the functional completeness and stability of the system. The results confirm that the proposed design fully meets the stringent timing and synchronization requirements of the CSNS-II project.