CONVERSION DEVICE AND CONVERSION METHOD FOR CONVERTING NUMERAL TO BE CONVERTED IN RESIDUE NUMBER SYSTEM INTO BINARY NUMERAL

摘要

PPROBLEM TO BE SOLVED: To convert a numeric value in a residue number system into a binary numeral at high speed with a small quantity of hardware. PSOLUTION: In a conversion device, a first modulus in the residue number system takes the value obtained by adding 1 to the exponentiation value of 2 exponentiated with a natural number larger than the product of moduli smaller than the first modulus. The conversion device comprises: a modulus corresponding conversion value generating section for generating, for each modulus, a modulus corresponding conversion value based on the value in which a residue value is multiplied by the product of moduli other than the modulus; and a modulus corresponding conversion value adding section for adding each modulus corresponding conversion value and calculating the binary numeral to be converted. The modulus corresponding conversion value generating section comprises: a partial bit string generating section for generating, on the basis of a bit string of residue value corresponding to the second modulus smaller than the first modulus, a partial bit string becoming a part of the modulus corresponding conversion value corresponding to the second modulus, and a partial bit string duplicating section for duplicating the partial bit string on a plurality of points of the modulus corresponding conversion value. PCOPYRIGHT: (C)2006,JPO&NCIPI