A VME barrel shifter system for event reconstruction for up to 3 Gbps signal trains

A VME barrel shifter system for event reconstruction was developed for the SDC experiment, together with a special semicustom switch IC. This system takes in fragments of a physical event through its inputs, combines and reorganizes the fragments, and produces a complete data set of the event from one of its outputs. The complete output data set for successive events is delivered to waiting computers at its outputs. Up to 3-Gb/s signal trains can be fed through the switch unit. Building blocks of this barrel shifter system are switch modules, optical to electrical and electrical to optical converter modules, and a dedicated crate. The switch modules are a dual-4×4/quad-2×2 unit and an 8×8 unit. They can be combined to deal with a very large number of I/O channels