FPGA-based 10G/40G Ethernet Firmware for Pixel Detector in SHINE

Background Shanghai HIgh repetition rate XFEL aNd Extreme light facility (SHINE) is a free electron laser facility, which will provide research methods such as high-resolution imaging for many disciplines. The pixel detector, which is in the pre-research stage, is one of most important components of the facility. Purpose The current target data rate of the pixel detector in SHINE is about 100 GB/s. Considering the high data rate, the 10G/40G Ethernet firmware for pixel detector in SHINE was developed on field programmable gate array (FPGA), which will lead to more integrated electronic design and make the system smaller. Methods The firmware converts the media independent interfaces (MII) of 10G and 40G Ethernet to each other and uses a polling method to process data from four 10G Ethernet channels. Based on the above methods, the firmware can merge four 10G Ethernet channels into one 40G Ethernet channel. Results and Conclusion The firmware successfully transmits data between the data source and the server. The bandwidth of the firmware is 36.66 Gbps when the computer equipped with 10G network interface controller (NIC) is set as the data source. Through joint test with the 1G/10G hub and SiTCP, the bandwidth of firmware is 36.3 Gbps. And 40 SiTCP nodes whose system clock frequency can exceed 125 MHz can be used as the data source of the firmware, which will provide a variety of technical solutions for pixel detector.