High speed EPICS data acquisition and processing on one VME board

A custom VME board is being designed at the Los Alamos Neutron Science Center (LANSCE) for high speed signal acquisition and processing. While it is desirable to design around the EPICS/VME platform, it can be difficult to process high-speed signals with long record lengths. The relatively slow data path between the IOC and the general-purpose computer makes real time computations impossible. Commercial VME processor boards can be used, but the data must still flow over the VME backplane in lieu of other traffic. This custom board is designed to overcome this problem by acquiring and processing the signal in one place, with the processed result presented at the VME interface instead of the raw data. The board consists of multiple front-end signal conditioners/digitizer cards plugged into the foundation 6U VME board with an embedded digital signal processor (DSP). The DSP is programmed in C to process the raw signal any way the user wants before writing results into a VME register map. The present front-end conditioner/digitizer cards are being designed with the LANSCE low momentum detector in mind, but other variations on this card could be developed. The architecture is flexible enough to deploy in many accelerator applications.