PARALLEL PROCESSING APPARATUS FOR BINARY TREE

摘要

A plurality of parallel processing elements are connected in a binary tree configuration, with each processing element except those in the highest and lowest levels being in communication with a single parent processing element as well as first and second (or left and right) child processing elements. Each processing element comprises a processor, a read/write or random access memory, and an input/output (I/O) device. The I/O device provides interfacing between each processing element and its parent and children processing elements so as to provide significant improvements in propagation speeds through the binary tree. The I/O device allows the presently preferred embodiment of the invention to be clocked at 12 megahertz, producing in the case of a tree of 1023 processors, each having an average instruction cycle time of 1.8 mu s, a system with a raw computational throughput of approximately 570 million instructions per second. The I/O device communicates data and queries from the root processing element to all other N processing elements in the array in one processor instruction cycle instead of in O(log2N) processor instruction cycles as in prior art binary tree arrays. Primitive queries are executed in parallel by each processing element and the results made available for reporting back to the root processing element. In several important cases, these results can be combined and reported back to the root processing element in a single processor instruction cycle instead of in O(log2N) processor instruction cycles as in prior art binary tree arrays. Thus, the elapsed time for a broadcast and report operation is in effect a constant time regardless of the number of processors in the array.