ATLAS Level-1 Calorimeter Trigger Upgrade for Phase-I Qian W Rutherford 2012 The ATLAS Level-1 Trigger requires several upgrades to maintain physics sensitivity as the LHC luminosity is raised. One of the most challenging is the electron trigger, with a major development planned for installation in 2018. New on-detector electronics will be installed to digitize electromagnetic calorimetry signals, providing trigger access to shower profile information. The trigger processing will be ATCA-based, with each multi-FPGA module processing ~1 Tbit/s of calorimeter digits within the current 2.5 microseconds Level-1 Trigger latency limit. This paper will address the system architecture and design, and give the status of a current technology demonstrator. INTNOTEATLASPUBL