| module cordic (clk,rst_n,ena,phase_in,sin_out,cos_out,eps);parameter DATA_WIDTH=8; parameter PIPELINE=8; input clk; input rst_n; input ena; input [DATA_WIDTH-1:0] phase_in; output [DATA_WIDTH-1:0] sin_out; output [DATA_WIDTH-1:0] cos_out; output [DATA_WIDTH-1:0] eps; reg [DATA_WIDTH-1:0] sin_out; reg [DATA_WIDTH-1:0] cos_out; reg [DATA_WIDTH-1:0] eps; reg [DATA_WIDTH-1:0] phase_in_reg; reg [DATA_WIDTH-1:0] x0,y0,z0; reg [DATA_WIDTH-1:0] x1,y1,z1; reg [DATA_WIDTH-1:0] x2,y2,z2; reg [DATA_WIDTH-1:0] x3,y3,z3; reg [DATA_WIDTH-1:0] x4,y4,z4; reg [DATA_WIDTH-1:0] x5,y5,z5; reg [DATA_WIDTH-1:0] x6,y6,z6; reg [DATA_WIDTH-1:0] x7,y7,z7; reg [1:0] quadrant[PIPELINE:0]; integer i; //get real quadrant and map to first_n quadrant always@(posedge clk or negedge rst_n) begin if(!rst_n) phase_in_reg<=8'b0000_0000; else if(ena) begin case(phase_in[7:6]) 2'b00:phase_in_reg<=phase_in; 2'b01:phase_in_reg<=phase_in-8'h40; //-pi/2 2'b10:phase_in_reg<=phase_in-8'h80; //-pi 2'b11:phase_in_reg<=phase_in-8'hc0; //-3pi/2 default:; endcase end end always@(posedge clk or negedge rst_n) begin if(!rst_n) begin x0<=8'b0000_0000; y0<=8'b0000_0000; z0<=8'b0000_0000; end else if(ena) begin x0<=8'h4D; //define aggregate constant Xi=1/P=1/1.6467=0.60725 (Xi=2^7*P+8'h4D) y0<=8'h00; z0<=phase_in_reg; end end //level 1 always@(posedge clk or negedge rst_n) begin if(!rst_n) begin x1<=8'b0000_0000; y1<=8'b0000_0000; z1<=8'b0000_0000; end else if(ena) if(z0[7]==1'b0) begin x1<=x0-y0; y1<=y0+x0; z1<=z0-8'h20; //45deg end else begin x1<=x0+y0; y1<=y0-x0; z1<=z0+8'h20; //45deg end end //level 2 always@(posedge clk or negedge rst_n) begin if(!rst_n) begin x2<=8'b0000_0000; y2<=8'b0000_0000; z2<=8'b0000_0000; end else if(ena) if(z1[7]==1'b0) begin x2<=x1-{y1[DATA_WIDTH-1],y1[DATA_WIDTH-1:1]}; y2<=y1+{x1[DATA_WIDTH-1],x1[DATA_WIDTH-1:1]}; z2<=z1-8'h12; //26deg end else begin x2<=x1+{y1[DATA_WIDTH-1],y1[DATA_WIDTH-1:1]}; y2<=y1-{x1[DATA_WIDTH-1],x1[DATA_WIDTH-1:1]}; z2<=z1+8'h12; end end //level 3 always@(posedge clk or negedge rst_n) begin if(!rst_n) begin x3<=8'b0000_0000; y3<=8'b0000_0000; z3<=8'b0000_0000; end else if(ena) if(z2[7]==1'b0) begin x3<=x2-{{2{y2[DATA_WIDTH-1]}},y2[DATA_WIDTH-1:2]}; y3<=y2+{{2{x2[DATA_WIDTH-1]}},x2[DATA_WIDTH-1:2]}; z3<=z2-8'h09; //14deg end else begin x3<=x2+{{2{y2[DATA_WIDTH-1]}},y2[DATA_WIDTH-1:2]}; y3<=y2-{{2{x2[DATA_WIDTH-1]}},x2[DATA_WIDTH-1:2]}; z3<=z2+8'h09; end end //level 4 always@(posedge clk or negedge rst_n) begin if(!rst_n) begin x4<=8'b0000_0000; y4<=8'b0000_0000; z4<=8'b0000_0000; end else if(ena) if(z3[7]==1'b0) begin x4<=x3-{{3{y3[DATA_WIDTH-1]}},y3[DATA_WIDTH-1:3]}; y4<=y3+{{3{x3[DATA_WIDTH-1]}},x3[DATA_WIDTH-1:3]}; z4<=z3-8'h04; //7deg end else begin x4<=x3+{{3{y3[DATA_WIDTH-1]}},y3[DATA_WIDTH-1:3]}; y4<=y3-{{3{x3[DATA_WIDTH-1]}},x3[DATA_WIDTH-1:3]}; z4<=z3+8'h04; end end //level 5 always@(posedge clk or negedge rst_n) begin if(!rst_n) begin x5<=8'b0000_0000; y5<=8'b0000_0000; z5<=8'b0000_0000; end else if(ena) if(z4[7]==1'b0) begin x5<=x4-{{4{y4[DATA_WIDTH-1]}},y4[DATA_WIDTH-1:4]}; y5<=y4+{{4{x4[DATA_WIDTH-1]}},x4[DATA_WIDTH-1:4]}; z5<=z4-8'h02; //4deg end else begin x5<=x4+{{4{y4[DATA_WIDTH-1]}},y4[DATA_WIDTH-1:4]}; y5<=y4-{{4{x4[DATA_WIDTH-1]}},x4[DATA_WIDTH-1:4]}; z5<=z4+8'h02; end end //level 6 always@(posedge clk or negedge rst_n) begin if(!rst_n) begin x6<=8'b0000_0000; y6<=8'b0000_0000; z6<=8'b0000_0000; end else if(ena) if(z5[7]==1'b0) begin x6<=x5-{{5{y5[DATA_WIDTH-1]}},y5[DATA_WIDTH-1:5]}; y6<=y5+{{5{x5[DATA_WIDTH-1]}},x5[DATA_WIDTH-1:5]}; z6<=z5-8'h01; //2deg end else begin x6<=x5+{{5{y5[DATA_WIDTH-1]}},y5[DATA_WIDTH-1:5]}; y6<=y5-{{5{x5[DATA_WIDTH-1]}},x5[DATA_WIDTH-1:5]}; z6<=z5+8'h01; end end always@(posedge clk or negedge rst_n) begin if(!rst_n) for(i=0;i<=PIPELINE;i=i+1) quadrant[i]<=2'b00; else if(ena) begin for(i=0;i<PIPELINE;i=i+1) quadrant[i+1]<= quadrant[i]; quadrant[0]<=phase_in[7:6]; endendalways@(posedge clk or negedge rst_n) begin if(!rst_n) begin sin_out<=8'b0000_0000; cos_out<=8'b0000_0000;eps<=8'b0000_0000; end else if(ena) case(quadrant[7]) 2'b00:begin sin_out<=y6; cos_out<=x6; eps<=z6; end 2'b01:begin sin_out<=x6; cos_out<=~(y6)+ 1'b1; eps<=z6; end 2'b10:begin sin_out<=~(y6)+ 1'b1; cos_out<=~(x6)+ 1'b1; eps<=z6; end 2'b11:begin sin_out<=~(x6)+ 1'b1; cos_out<=y6; eps<=z6; end encaseendendmodule |
