INVERSE ELEMENT ARITHMETIC UNIT AND METHOD

摘要

PROBLEM TO BE SOLVED: To provide an inverse element arithmetic unit capable of speedily obtaining an inverse element. SOLUTION: This unit is provided with a memory part for holding the four values of intermediate values U2, V2, U3 and V3, a Ramer coefficient operation part for calculating a multiplication coefficient in accordance with the algorithm of a Ramer method by using higher k-bits obtained by removing the higher bits of a value 0 in the intermediate value U3 and the k-bits of the same place in V3 and an inner variable update part for judging whether the intermediate value can be updated or not by the obtained multiplication coefficient and updating the intermediate value by the obtained multiplication coefficient when it is judged that it can be updated and obtaining the approximate quotient of the intermediate values U3 and V3 by an approximate quotient operation part when it is judged that it cannot be updated and updating the intermediate value by using the approximate quotient. Thus, an inverse element operation is performed in accordance with the algorithm of the Ramer method by controlling the respective parts.