| 摘要 |
PURPOSE:To attain compact and high speed division by previously storing the reciprocal of a value corresponding to uppermost M digits D of a divisor D in a reciprocal table and executing collective type division through the use of the value and the reciprocal of lowermost N-M digits of the divisor D. CONSTITUTION:A ROM1 is accessed by D0, and the reciprocal 1/D0' of D0' is outputted, and the product D1'/D0'(=r) of 1/D0' and the inversion of residual lowermost N-M bits of the divisor is obtained in a multiplier 12, whereby a product A/D0' is calculated. Next, a product r<2> is calculated in the multiplier 12, and 1+r is calculated by using an adder equivalence 14, whereby the product (A/D0')(1+r) with the product A/D0' which has previously been obtained is calculated in the multiplier 12. Next, a product (r<4>) is similarly calculated in the multiplier 12 and 1+r<2> is calculated in the adder equivalence 14, whereby a product (A/D0')(1+r)(1+r<2>) with preceding (A/D0')(1+r) is calculated in the multiplier 12. Next, 1+r<4> is calculated in the adder equivalence 14 and a product (A/D0')(1+r)(1+r<2>)(1+r<4>) with previously obtained (A/D0')(1+r)(1+r<2>) is calculated in the multiplier 12, and the result is outputted as a quotient. |
