New development in the CMS ECAL Level-1 trigger system to meet the challenges of LHC Run 2

The CMS Electromagnetic Calorimeter (ECAL) provides energy sums to the Level-1 calorimeter trigger at a rate of 40 MHz. The processing of these trigger primitives (TPs) is performed by dedicated trigger concentrator cards (TCCs) located in the CMS service cavern. Updates to the functionality of the TCCs are required to respond to the challenging experimental conditions of LHC Run 2, where the center-of-mass of proton-proton collision energy was 13 TeV and the peak instantaneous luminosity of the proton beams reached 2x10$^{34}$ cm$^{-2}$s$^{-1}$. A new algorithm, termed the Cumulative Overflow Killing Engine (COKE), has been developed and implemented via software and firmware updates to the TCCs in order to automatically detect and mask noisy or problematic TPs via configurable thresholds. The auto-recovery of the TCC from Single Event Upsets (SEUs) has also been improved. This allows the detector to trigger efficiently without direct expert intervention, and the thresholds can evolve with evolving LHC conditions.