PARALLEL STRING PROCESSOR AND METHOD FOR A MINICOMPUTER

摘要

A processor is disclosed for use in a computer system for comparing a number of bytes simultaneously in order to locate a particular character in a string of data. The processor includes a register (B) for holding the data bytes, a register (A) for storing the particular character, a comparison circuit (102, 109) for simultaneously comparing the bytes of the first register (B) with the bytes of the second register (A), and a circuit (115, 122) for generating indicator bits when a match has been found between the two registers. Microcode instructions cause the system to branch to a predetermined memory location when the control character has been located and to branch to a second predetermined memory location when no control character is found in the data string. A second portion of the processor finds the indicator bits generated from the circuit (115, 122) which have a predetermined characteristic and thus identifies the position of a particular byte in the data word that has the selected predetermined characteristic. In particular, four instructions are provided which find the first matching byte; the first non-matching byte; the first matching byte after the first non-matching byte; and the first non-matching byte after the first matching byte. A number of different operations can be performed based upon the output of the circuit (115, 122) to accomplish in one instruction operations that previously required a large number of instructions.