A routing model for the NCR GAPP

Abstract

A routing model for the NCR Geometric Arithmetic Parallel Processor (GAPP) is described. The objective is to permit virtual reconfigurations of the array of processing elements (PEs) and nonlocal connections between arbitrarily distant PEs. The main feature of the model is the multiplexing of two instruction sets, over an additional pin, controlling either the SIMD (single-instruction, multiple-data-stream) machine or the set of router-cells organized as a hypercube network. A description is given of which structural changes are applied to the GAPP SIMD machine to support the routing scheme, and the operations concurrently executed by the router-cells for receiving, delivering or forwarding messages. A functional description of a semantic network which was designed expressly to test the routing model is given together with examples of its use.<>