| 摘要 |
PROBLEM TO BE SOLVED: To provide a reciprocal operator which can perform reciprocal operation at a small cycle number.SOLUTION: Provided is a reciprocal operator 100 for computing a reciprocal of an input value in a Galois field of m bits. As for a U register 10 and a V register 12, when 0 is continuously included across y bits from lowermost bits toward upper bits, the U register 10 and the V register 12 are right-shifted by y bits. In linkage with the right-shift, the V register 12 and a G1 register 14 are subjected to y times of 1/Z processing. When the lowermost bits of the U register 10 and the V register 12 are both 1, the one with a higher degree is updated by an addition result of the U register 10 and the V register 12. Further, in linkage with the update, when a degree of the U register 10 is higher, the G1 register 14 is updated by an addition result of the G1 register 14 and a G2 register 16, whereas when a degree of the V register 12 is higher, the G2 register 16 is updated by an addition result of the G1 register 14 and the G2 register 16. |
