JPS55116143A - Data processor - Google Patents

Abstract

PURPOSE: To make it possible to find an accurate quotient at a high speed by performing a process by providing a method of judging whether the quotient should be corrected or not to a division system which finds an approximate solution by repeating multiplication.

CONSTITUTION: An approximate solution n-bit more than m-bits, the number of effective digit needed for a quotient, is found by repeating multiplication and then inputted to output register 9. Then, n-bits of register 9 are inputted to correction decision circuit 20 to check whether correction arithmetic of the quotient is required or not and the result is reported to correction arithmetic control circuit 21. When the correction is required, the contents of register 9 are outputted. Once the correction is judged to be required, circuit 21 actuates division control part 23 to performs the multiplication processing again, and consequently an approximate solution with a many number of effective digits to check the correction arithmetic of quotient Q is required or not. When the correction of quotient Q is judged to be needed, circuit 21 actuates input data control part 22, multiplication control part 24 and subtraction control part 25 to find the solution of dividend-Q divisor=R, so that Q when R≥0 or a value obtained by subtracting "1" from the lowest-order bit position of Q when R<0 will be outputted as the final quotient.

COPYRIGHT: (C)1980,JPO&Japio