External scrubber implementation for the ALICE ITS Readout Unit

The ALICE Inner Tracking System is currently being upgraded for the LHC run 3. The whole detector and its associated systems, including the readout electronics are being designed and built. The Readout Unit is responsible for the first level of data aggregation and detector control in the ITS detector. 192 of the Readout Units will be operational in the ALICE cavern, where their proximity to the beam makes radiation tolerant design for all components mandatory. The Readout Unit is designed with a Xilinx Kintex Ultrascale at its core, providing high-density reconfigurable logic and high-speed IOs to handle the data-load from the sensors. Inclusion of a Microsemi flash-based auxiliary FPGA on the Readout Unit enables fault-tolerant operation, by implementing periodic blind scrubbing to correct single event upsets in the configuration memory of the SRAM-based Xilinx FPGA. This contribution discusses the external scrubber implementation for the Readout Unit for the ALICE ITS upgrade.