The Level-1 Global Muon Trigger for the CMS Experiment

The three independent Level-1 muon trigger systems in CMS deliver up to 16 muon candidates per bunch crossing, each described by transverse momentum, direction, charge and quality. The Global Muon Trigger combines these measurements in order to find the best four muon candidates in the entire detector and attaches bits from the calorimeter trigger to denote calorimetric isolation and confirmation. A single-board logic design is presented: via a special front panel and a custom back plane more than 1100 bits are received in every bunch crossing and processed without dead-time by pipelined logic implemented in five large and several small Xilinx FPGAs.