Patent ID: 7634524
Filing Date: 2009-12-15
Classification: G06F

Abstract:
1. A function arithmetic method comprising: a cyclic equation setting step performed by an arithmetic unit of a circuit for transforming and setting a Taylor series equation for calculating a sine function into a single cyclic equation common to terms of the Taylor series equation, the single cyclic equation having a new known number Q that is defined by multiplying a known number Q and the square of a variable X, shifting the result by a shift number S and then adding a constant K thereto; an adjustment step performed by an adjustment unit of said circuit for adjusting and preparing the shift number S such that within a variation range of the variable X the variable X has a maximum value 1 with the constant K being not greater than 1; a cyclic equation executing step preformed by the adjustment unit of said circuit for inputting and converting angle information i to the variable X, and executing the cyclic equation in sequence from higher order term to lower order term for the number of terms of the Taylor series equation to derive a sine function of the angle information i; and an output step outputting the sine function for a fast Fourier transform.