Construction of a compact DAQ-system using DSP-based VME modules

A data-acquisition system based upon the SHARC digital-signal-processor (DSP) has been developed. Either one or two DSPs are mounted onto VME boards, WS2126. VME-to-VME data transfer utilizes SHARC links (33.7 MB/s of measured transfer rate), routed onto a front panel of the WS2126 by I/O piggy pack modules, WS9002. The system has been designed for readout of 81,920 FADC (flash analog-to-digital converter) channels at a maximum trigger rate of 500 Hz. This system could be accomplished in a compact setup of four FADC readout VME crates and one master-control VME crate (for event-building and run-control). The system was tested for readout of the BELLE silicon vertex detector.