To achieve arctan calculation in second quadrant or third quadrant
the improvement measure of in creasing the two 45° rotation on traditional CORDIC algorithm is proposed. The hardware pipeline structure of the modified CORDIC algorithm is put forward and simulated on FPGA stratix EP1S10F484C5 of A1tera company. The simulation results indicated that the modified CORDIC algorithm result is essentially coincident with theoretical value and has less errors
therefour
the modified CORDIC algorithm can be used for arctan calculation of any point in coordinate plane.