John Stylianos Pezaris, NuMesh CFSM Revision 2: A Comparative Analysis of Three Candidate Architectures, Master's thesis, February 1993.

Abstract:

This thesis lays the architectural groundwork for the third implementation of the NuMesh Communications Finite State Machine (CFSM), a four-neighbor multicomputer communications network router. Desired characteristics are (1) efficient support for compile-time scheduled routing, (2) good support for run-time scheduled routing, (3) one-chip implementability.

Three candidate Revision 2 CFSM architectures are proposed: A1, a traditional uniprocessor; A2, a crossbar-based multiprocessor; and A3, a bus-based multiprocessor. Each architecture is first presented and then used to implement a suite of 11 hand-coded examples. Through analysis of these examples, the third architecture, A3, is argued to be the best candidate and most applicable to the NuMesh model of primarily synchronous communication.

During the presentation and comparative evaluation of the three candidate architectures, a series of design questions are approached: the advantage of multiple FSMS over multiple PCs; the necessary hardware to support a large class of communications models; the advantages of a central FSM in a multi-FSM design; the importance of full/empty routing bits; the advantage of crossbar over bus-based datapaths; the problem of scalable reset and booting.