Emulation of a Virtual Shared Memory Architecture

In designing a multiprocessor architecture, the motivating factors are that the architecture should be general purpose, easier to program and at the same time scalable. The Data Diffusion Machine (DDM) seeks to fulfil such criteria. The DDM provides shared-data access on distributed memory hardware, allowing data to freely migrate to processors on demand. The DDM concept was originally proposed in terms of a hierarchy of buses, but has since been elaborated for different interconnects. This thesis presents a link-based realisation of the architecture and a link-based coherence protocol which is central in maintaining coherence of data. The link-based protocol exploits the combining properties of the DDM network to minimise traffic in the DDM hierarchy. The protocol also contains efficient and general support for synchronisation