DIVISION/ROOT EXTRACTION ARITHMETIC METHOD AND DEVICE

摘要

PURPOSE: To attain the high speed of a convergence type division using a Newton-Raphson method. ;CONSTITUTION: This device is equipped with a low-order digit multiplier 21, high-order digit multiplier 22, redundant binary/binary converting part 23, data ROM 24 which stores the double value 2R0 and squared value R0² of the initial approximate value of the inverse number of a divisor Y, data aligner 61, sticky bit preparation and rounding processing part 62, and try state buffers 41-48 which transmit the outputs of the high-order digit and low-order digit multipliers 22 and 21 to an X bus 51 and a Y bus 52. Especially the first convergent factor R1 among the softening type convergent factors is searched by the high-order digit multiplier 22 by the arithmetic operation of -R1_rb=Y×R02-2R0. And also, the search of a high-order digit approximate quotient and the search of a low-order digit approximate inverse number are processed in parallel, and a test related with the high-order digit approximate quotient and the search of the low-order digit approximate quotient are processed in parallel, by the parallel operations of the high-order digit multiplier 22 and the low-order digit multiplier 21.;COPYRIGHT: (C)1994,JPO&Japio