Overview of the HL-LHC Upgrade for the CMS Level-1 Trigger

In view of the High-Luminosity LHC, the Compact Muon Solenoid (CMS) experiment is planning to entirely replace its trigger and data acquisition system. Novel design choices are being explored through ATCA prototyping platforms and newly available interconnect technologies proving links up to 28~Gb/s. Higher-level trigger object reconstruction is performed through large scale FPGAs (such as Xilinx UltraScale) handling over 50~Tb/s of fine granularity detector data with an event rate of 750~kHz.