Method of cordic computing vector angle and electronic apparatus using the same

A method of computing a vector angle by using a coordinate rotation digital computer (CORDIC), comprising:

• obtaining an initial coordinate, a base phase and an index;
• judging a shift unit according to the initial coordinate;
• performing a phase error detection on the initial coordinate so as to lock a phase error according to the shift unit;
• performing a loop filtering, wherein a first transfer function is used to filter out the high-frequency component of the phase error;
• performing an update processing and computing an intermediate coordinate;
• providing a rotation angle to the index according to an iteration look up table;
• performing a numerical controlled oscillating to accumulate the rotation angle so as to obtain a rotated angle;
• performing a dynamic shifting processing of the iteration look up table;
• and
• performing a second transfer function processing on the rotated angle to obtain a normalized rotated angle, wherein when the difference between the normalized rotated angle and the base phase is greater than a predetermined value, the above-mentioned steps are repeated;
• otherwise, a phase compensation processing is performed and the intermediate coordinate and the normalized rotated angle are output.