MULTIPROCESSING(second)
Classification perforated metal .Multiprocessor systems may be classified into four types:single instruction stream, single data stream; single instruction stream, multiple data stream; multiple instruction stream, single data stream; and multiple instruction stream, architectural wire mesh multiple data stream. Systems in the MISD category are rarely built. The other three architectures may be distinguished simply by the differences in their respective instruction cycles: In an SISD architectrue there is a single instruction cycle; operands are fetched serially into a single processing unit before execution. An SIMD architecture also has a single instruction cycle, 冲孔网 but multiple sets of operands may be fetched to multiple processing units and may be operated upon simultaneously within a single instruction cycle. Multiple functional-unit, array, vector, and pipeline processors are in this category.