  In Run-3, beginning in 2022, the LHCb software trigger will start
reconstructing events at the LHC average crossing rate of 30 MHz. Within the
upgraded DAQ system, LHCb established a testbed for new heterogeneous computing
solutions for real-time event reconstruction, in view of future runs at even
higher luminosities. One such solution is a highly-parallelized custom tracking
processor ("Artificial Retina"), implemented in state of the art FPGA devices
connected by fast serial links. We describe the status of a realistic prototype
for the reconstruction of pixel tracking detectors that will run on real data
during Run-3.
