A Programmable Data Source for SCI

Paper: 239
Session: B (poster)
Presenter: Kolya, Scott, University of Manchester, Manchester
Keywords: SCI, network performance, switches (eg ATM


A Programmable Data Source for SCI

Abstract

A VME based programmable Data Source & Sink has been designed and
operated in small networks of up to twenty nodes, implemented with
first and second generation commercial SCI (Scalable Coherent
Interface) interface chips produced by Dolphin Interconnect Solutions
and organised into various configurations of rings and switches.
The Data Source uses the Dolphin LC1 chip, with low cost
conventional static RAM for inward & outgoing data, deep counters
to allow extended checks on packet loss, and a minimalist A24 VME for
access to packet data and control. The board can generate and sink
traffic patterns at sustained rates of a substantial fraction of the
link bandwidth - significantly higher than our previous interfaces
implemented with first generation interface chips and limited by host
performance. The design and operation of the Data Source is presented,
together with preliminary results of a study of loading effects in the
various network configurations, operating close to or at saturation.
Our plans for incorporating this device into a demonstrator system for
the Atlas second level trigger are also presented.


NB: This is a poster session submission to back up the results presented in
one or both of our more general presentations (Robin Middleton and R.E.
Hughes-Jones).