NUMERICALLY-CONTROLLED OSCILLATOR AND OPERATING METHOD FOR GENERATING COSINE AND SINE SIGNAL USING ONLY COSINE LOOK-UP TABLE

摘要

A numerically-controlled oscillator capable of outputting a sine signal and a cosine signal, and an operating method thereof are provided to simply calculate a first address and a second address about an input signal phase value by using a function value calculated by a cosine function. An address generator(34) outputs a first address(Ac) about a function value of a cosine signal corresponding to a phase value of an input signal, a first code(Sc) about a code conversion of a function value of the cosine signal, a second address(As) about a function value of a sine signal, and a second code(Ss) about a code conversion of a function value of the sine signal. A look up table memory(32) outputs a first function value and a second function value corresponding to the first address and the second address by using a look up table. A code converter(36) outputs the cosine signal and the sine signal by converting codes of the first function value and the second function value according to a set reference.