`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company:
// Engineer:
//
// Create Date: 03/20/2018 08:47:34 PM
// Design Name:
// Module Name: Cordic_base
// Project Name:
// Target Devices:
// Tool Versions:
// Description:
//
// Dependencies:
//
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
//
//////////////////////////////////////////////////////////////////////////////////


module cordic_beh();
/**
* Cordic algorithm
*/
//Input arguments
real angle_deg=45;
parameter integer iterations=20;


parameter integer FXP_SCALE=10000;
parameter integer data_vec_size=15;

//program constants
reg signed [data_vec_size:0] pi=3.1415926535897932384626433832795;
reg signed [data_vec_size:0] t_angle = (pi*angle_deg)*FXP_SCALE/180; //Input parameter. The angle

//Table of arctan (1/2^i)
// Note. Table initialization below is not correct for Verilog. Select System-Verilog mode
// in your simulator in the case of syntax errors
reg signed [data_vec_size:0] arctan[0:23] = {
0.78539816339745*FXP_SCALE ,  0.46364760900081*FXP_SCALE  , 0.24497866312686*FXP_SCALE ,  0.12435499454676*FXP_SCALE,
0.06241880999596*FXP_SCALE ,  0.03123983343027*FXP_SCALE ,  0.01562372862048*FXP_SCALE  , 0.00781234106010*FXP_SCALE,
0.00390623013197*FXP_SCALE ,  0.00195312251648*FXP_SCALE  , 0.00097656218956*FXP_SCALE  , 0.00048828121119*FXP_SCALE,
0.00024414062015*FXP_SCALE ,  0.00012207031189*FXP_SCALE ,  0.00006103515617*FXP_SCALE  , 0.00003051757812*FXP_SCALE,
0.00001525878906*FXP_SCALE ,  0.00000762939453*FXP_SCALE ,  0.00000381469727*FXP_SCALE ,  0.00000190734863*FXP_SCALE,
0.00000095367432*FXP_SCALE ,  0.00000047683716*FXP_SCALE  , 0.00000023841858*FXP_SCALE  , 0.00000011920929*FXP_SCALE
};
reg signed [data_vec_size:0] Kn[0:23] ={
0.70710678118655*FXP_SCALE,   0.63245553203368*FXP_SCALE,   0.61357199107790*FXP_SCALE,   0.60883391251775*FXP_SCALE,
0.60764825625617*FXP_SCALE,   0.60735177014130*FXP_SCALE,   0.60727764409353*FXP_SCALE,   0.60725911229889*FXP_SCALE,
0.60725447933256*FXP_SCALE,   0.60725332108988*FXP_SCALE,   0.60725303152913*FXP_SCALE,   0.60725295913894*FXP_SCALE,
0.60725294104140*FXP_SCALE,  0.60725293651701 *FXP_SCALE,   0.60725293538591*FXP_SCALE,   0.60725293510314*FXP_SCALE,
0.60725293503245*FXP_SCALE,   0.60725293501477*FXP_SCALE,   0.60725293501035*FXP_SCALE,   0.60725293500925*FXP_SCALE,
0.60725293500897*FXP_SCALE,   0.60725293500890*FXP_SCALE,  0.60725293500889 *FXP_SCALE,   0.60725293500888*FXP_SCALE
}; //Cordic scaling factor for 10 iterations
//Variables
reg signed [data_vec_size:0] cos=1*FXP_SCALE; //Initial vector x coordinate
reg signed [data_vec_size:0] sin=0; //and y coordinate
reg signed [data_vec_size:0] angle = 0.0; //A running angle
integer i, d;
reg signed [data_vec_size:0] tmp;

reg signed [data_vec_size*2:0] sin_out;
reg signed [data_vec_size*2:0] cos_out;

initial //Execute only once
begin
 for ( i = 0; i < iterations-1; i = i + 1) //Ten algorithm iterations
 begin
 if( t_angle > angle )
     begin
         angle = angle + arctan[i];
         tmp = cos - ( sin / 2**i );
         sin = ( cos / 2**i ) + sin;
         cos = tmp;
     end
 else
     begin
         angle = angle - arctan[i];
         tmp = cos + ( sin / 2**i );
         sin = - ( cos / 2**i) + sin;
         cos = tmp;
     end //if
 end //for
 //Scale sin/cos values
sin_out = Kn[iterations-1] * sin;
cos_out = Kn[iterations-1] * cos;
sin_out =sin_out/FXP_SCALE;
cos_out =cos_out/FXP_SCALE ;
$display("sin=%f, cos=%f, with factor scale = %d", sin_out, cos_out, FXP_SCALE);
end
endmodule