A programmable routing controller supporting multi-mode routing and switching in distributed real-time systems.

Abstract

Distributed systems with point-to-point interconnection networks are natural candidate architectures for supporting embedded real-time applications due mainly to their potential for high-performance and high-dependability with the multiplicity of processors and internode routes. In addition, distributed systems based on point-to-point interconnection networks also hold great promise for delivering systems with some level of intermediate dependability: something not as expensive and complete as the ultra-dependable systems used in mission-critical applications but more dependable than systems constructed using standard networking techniques and commercially-available components. This dissertation investigates an area of the design space in which a homogeneous distributed computing system is constructed that has the potential for an intermediate level of dependability. Most of the characteristics of this system can be traced to either the parallel computing domain, the distributed systems domain, or the ultra-dependable systems domain. The unifying feature not explicitly present in the three "parent" domains is the flexibility of the underlying communication support hardware which allows these other features to co-exist while supporting the end goals. One of the central themes of this dissertation is that if flexibility is provided in the front-end routing hardware, the management of issues related to operating in this hybrid domain are then possible. To that end, most of the results presented here focus on the development and implementation of a programmable routing controller (PRC) that acts both as a single sample in the design space and supports further exploration of the design space. Specifically, this work proposes an architecture and an implementation for a front-end programmable routing controller that supports multiple routing and switching schemes. We then proceed to analyze the performance of one of the supported switching schemes for a hexagonal mesh interconnection network based on the capabilities provided by the PRC. We then conclude by showing how the capability of supporting multiple routing and switching schemes simultaneously offers great potential for supporting real-time communication subsystems.