Hermes — a robust, low latency, optical link protocol for synchronous data transfer at commercial asynchronous line rates. (1st June 2022)

• Record Type: Journal Article
• Authors: Adamidis, K.; Bestintzanos, I.; Foudas, C.; Howard, A.; Iles, G.M.; Mallios, S.; Williams, T.
• Is Part Of: Journal of instrumentation. Volume 17:Number 6(2022)
• Publication Date: 2022-06-01
• Subjects: Digital electronic circuits -- VLSI circuits; Scientific apparatus and instruments -- Periodicals; 502.84
• DOI: 10.1088/1748-0221/17/06/C06002
• Languages: English
• ISSNs: 1748-0221

Abstract

Abstract: The CMS Level-1 Trigger at HL-LHC and associated upstream systems employ more than 10000 25 Gb/s optical links, transferring almost a Pb/s of data synchronously between the different back-end processing nodes. Stable operation of these links is essential to avoid the injection of erroneous signals into the trigger path, potentially leading to a flood of false triggers or data loss. The Hermes protocol, implemented on Xilinx UltraScale+ FPGAs, provides this stability while operating at asynchronous, industry standard line rates. The protocol design as well as results on the performance from extensive testing are presented here.