The Barrel Muon Track finder of the CMS experiment at the Large Hadron Collider uses custom
processors to identify muons and measure their momenta in the central region of the CMS detector. An upgrade of the L1 tracking algorithm is presented, featuring a Kalman Filter in FPGAs,
implemented using High Level Synthesis tools. The matrix operations are mapped to the DSP
cores reducing resource utilization to a level that allows the new algorithm to fit in the same
FPGA as the legacy one, thus enabling studies during nominal CMS data taking. The algorithm
performance has been verified in CMS collisions during 2018 operations. The algorithm is also
proposed for standalone muon tracking at the High Luminosity LHC. The algorithm development
is complemented by ATCA processor R&D featuring a large ZYNQ Ultrascale+ SoC with high
speed optical links.