Interconnecting off-the-shelf microprocessors

This paper outlines the design and analysis of a crossbar-type interconnection network that can be used with off-the-shelf microprocessor components to construct a four-processor/eight-memory module multiprocessor system. The only custom component is an interconnection (ICN) chip presently being fabricated by the authors. The ICN chip integrates 4 x 8 crosspoints for a 3-bit bus slice together with related priority circuitry into a single component. System design using the ICN chip is illustrated with the Intel 8086 family of microprocessor components. An analysis of the resulting system is presented. The degradation of performance resulting from the memory interference associated with multiprocessors is shown to be small compared to that resulting from the setup time required by the interconnection logic.