The development of Global Feature eXtractor (gFEX) - the ATLAS calorimeter Level 1 trigger for ATLAS at High Luminosity LHC

As part of the ATLAS Phase-I Upgrade, the gFEX is designed to help maintain the ATLAS Level-1 trigger acceptance rate with the increasing LHC luminosity. The gFEX identifies patterns of energy associated with the hadronic decays of high momentum Higgs, W, & Z bosons, top quarks, and exotic particles in real time at the 40MHz LHC bunch crossing rate. The prototype v1 and v2 were designed and fully tested in 2015 and 2016 respectively. A pre-production gFEX board has been manufactured, which is an ATCA module consisting of three UltraScale+ FPGAs and one ZYNQ UltraScale+, and 35 MiniPODs are implemented in an ATCA module. This board receives coarse-granularity (0.2x0.2) information from the entire ATLAS calorimeters on up to 300 optical fibers and 96 links to the L1Topo at the speed up to 12.8 Gb/s.