On-line data reduction on the ALICE SDD data concentrator card CARLOSrx

This work deals with the design of an upgraded firmware version of the CARLOSrx data concentrator board which is part of the readout chain of the silicon drift detector at the ALICE experiment at the LHC. The goal is to on-line reduce the SDD data volume size in low-occupancy (cosmic and p-p) runs, thus leading to a decreased data throughput and a reduced amount of data to be stored. In order to reach this goal a transition from a variable-length encoding to a fixed 32-bit encoding scheme has been adopted, together with the elimination of the redundant information performed in parallel over the 12 data channels processed by each CARLOSrx board.