A Built-in Circuit for Self-Repairing Mesh-Connected Processor Arrays with Spares on Diagonal

Abstract

We present a built-in self-restructuring system for a mesh-connected processor array where faulty processing elements are compensated for by spare processing elements located on a diagonal. First, an algorithm for restructuring the array with faulty processing elements is presented. The reliability of the system is analyzed by simulation. It is compared with that of an array with spare processing elements on a line at the edge of the array which has the same number of spare processing elements as that in the proposed array. It is shown that the former is fairly higher than the latter. Next, a logical circuit realizing the algorithm is presented. The circuit controls interconnection of processing elements and is so simple that its hardware overhead is small. The proposed system is effective for the case where each processing element is fairly reliable and the small number of spares will be enough for retaining the reliability of an array so high under small hardware overhead. It is also effective in enhancing especially the run-time reliability of a processor array.