cordic计算sin，cos出错
万能的坛子，请教下这个正弦值在过零点和峰值点峰谷点的值是怎么出现异常的~{:cry:}代码如下：
module cordic
#(parameter DATA_WIDTH=8)
(
input clk,
input rst_n,
input ena,
input phase_in,
output reg sin_out,
output reg cos_out,
output reg eps
);
localparam PIPELINE=8;
reg phase_in_reg;
reg x0,y0,z0;
reg x1,y1,z1;
reg x2,y2,z2;
reg x3,y3,z3;
reg x4,y4,z4;
reg x5,y5,z5;
reg x6,y6,z6;
reg x7,y7,z7;
reg quadrant ;
integer i;
always @(posedge clk,negedge rst_n)
begin
if(!rst_n)
phase_in_reg <= 8'b0;
else
if(ena)
begin
case(phase_in)//phase_in/360*256,so phase_in is discrete 360/256=1.40625 degree
2'b00: phase_in_reg <= phase_in; //when phase_in <90 degree,phase_in =phase_in
2'b01: phase_in_reg <= phase_in-8'h40;//when phase_in >=90 degree,phase_in-90
2'b10: phase_in_reg <= phase_in-8'h80;//when phase_in >=180 degree,phase_in-180
2'b11: phase_in_reg <= phase_in-8'hc0;//when phase_in >=270 degree,phase_in-270
default:;
endcase
end
end // this program is intend to turn phase_in into
always @ (posedge clk,negedge rst_n)//circul cordic
begin
if(!rst_n)
begin
x0<=8'b0;
y0<=8'b0;
z0<=8'b0;
end
else
if(ena)
begin
x0 <= 8'h4D; //0.60725*2^7,gian K
y0 <= 8'h00;
z0 <= phase_in_reg;//start values of x0,y0,z0,
end
end
//level 1
always @ (posedge clk,negedge rst_n)
begin
if(!rst_n)
begin
x1 <=8'b0;
y1 <=8'b0;
z1 <=8'b0;
end
else
if(ena)
if(z0==1'b0)// if MSB of z0 is not 1,z0 is positive,of course it is true
begin
x1 <= x0-y0;
y1 <= y0+x0;
z1 <=z0-8'h20; //45deg
end
else
begin //z0 is defined as positive value
x1<=x0+y0;
y1<=y0-x0;
z1<=z0+8'h20;
end
end
//level 2
always @ (posedge clk,negedge rst_n)
begin
if(!rst_n)
begin
x2 <=8'b0;
y2 <=8'b0;
z2 <=8'b0;
end
else
if(ena)
if(z1==1'b0)// if z0 is still > 0
begin
x2 <= x1-{y1,y1};//concatation why not shift operation
y2 <= y1+{x1,x1};//make MSB stable
z2 <=z1-8'h12;//26deg
end
else
begin
x2<= x1+{y1,y1};
y2<= y1-{x1,x1};
z2<= z1+8'h12;
end
end
//level 3
always @ (posedge clk,negedge rst_n)
begin
if(!rst_n)
begin
x3 <=8'b0;
y3 <=8'b0;
z3 <=8'b0;
end
else
if(ena)
if(z2==1'b0)
begin
x3 <= x2-{{2{y2}},y2};//{y2,y2,y2}
y3 <= y2+{{2{x2}},x2};
z3 <=z2-8'h09;//14deg
end
else
begin
x3<= x2+{{2{y2}},y2};
y3<= y2-{{2{x2}},x2};
z3<= z2+8'h09;
end
end
//level 4
always @ (posedge clk,negedge rst_n)
begin
if(!rst_n)
begin
x4 <=8'b0;
y4 <=8'b0;
z4 <=8'b0;
end
else
if(ena)
if(z3==1'b0)
begin
x4 <= x3-{{3{y3}},y3};
y4 <= y3+{{3{x3}},x3};
z4 <= z3-8'h04;//7deg
end
else
begin
x4<= x3+{{3{y3}},y3};
y4<= y3-{{3{x3}},x3};
z4<= z3+8'h04;
end
end
//level 5
always @ (posedge clk,negedge rst_n)
begin
if(!rst_n)
begin
x5 <=8'b0;
y5 <=8'b0;
z5 <=8'b0;
end
else
if(ena)
if(z4==1'b0)
begin
x5 <= x4-{{4{y4}},y4};
y5 <= y4+{{4{x4}},x4};
z5 <= z4-8'h02;//4deg
end
else
begin
x5<= x4+{{4{y4}},y4};
y5<= y4-{{4{x4}},x4};
z5<= z4+8'h02;
end
end
//level 6
always @ (posedge clk,negedge rst_n)
begin
if(!rst_n)
begin
x6 <=8'b0;
y6 <=8'b0;
z6 <=8'b0;
end
else
if(ena)
if(z5==1'b0)
begin
x6 <= x5-{{5{y5}},y5};
y6 <= y5+{{5{x5}},x5};
z6 <= z5-8'h01;//2deg
end
else
begin
x6<= x5+{{5{y5}},y5};
y6<= y5-{{5{x5}},x5};
z6<= z5+8'h01;
end
end
//level 7
always @ (posedge clk,negedge rst_n)
begin
if(!rst_n)
begin
x7 <=8'b0;
y7 <=8'b0;
z7 <=8'b0;
end
else
if(ena)
if(z6==1'b0)
begin
x7 <= x6-{{6{y6}},y6};
y7 <= y6+{{6{x6}},x6};
z7 <= z6-8'h00;//2deg
end
else
begin
x7<= x6+{{6{y6}},y6};
y7<= y6-{{6{x6}},x6};
z7<= z6+8'h00;
end
end
//-------
always @ (posedge clk,negedge rst_n)
begin
if(!rst_n)
for(i=0;i<=PIPELINE;i=i+1)
quadrant<=2'b00;
else
if(ena)
begin
for(i=0;i<PIPELINE;i=i+1)
quadrant<=quadrant;
quadrant<=phase_in;
end
end //remark the quadrant of the first eight phases_in
//------------
always @ (posedge clk,negedge rst_n)
begin
if(!rst_n)
begin
sin_out <= 8'b0;
cos_out <= 8'b0;
eps <= 8'b0;
end
else
if(ena)
case(quadrant)//if the phase is in first quadrant,the sin(X)=sin(A),cos(X)=cos(X)
2'b00:
begin
sin_out <= y7;
cos_out <= x7;
eps <= z7;
end
2'b01:
begin //if the phase is in second quadrant,the sin(X)=sin(A+90)=cosA,cos(X)=cos(A+90)=-sinA
sin_out <= x7;
cos_out <= ~(y7)+1'b1;
eps <= z7;
end
2'b10:
begin//if the phase is in third quadrant,the sin(X)=sin(A+180)=-sinA,cos(X)=cos(A+180)=-cosA
sin_out <= ~(y7)+1'b1;
cos_out <= ~(x7)+1'b1;
eps <= z7;
end
2'b11: //if the phase is in forth quadrant,the sin(X)=sin(A+270)=-cosA,cos(X)=cos(A+270)=cosA
begin
sin_out <= ~(x7)+1'b1;
cos_out <= y7;
eps <= z7;
end
endcase
end
endmodule 抢沙发 LZ的分析仪是什么型号？ Eps是什么啊 bigZ 发表于 2014-6-30 20:46
LZ的分析仪是什么型号？
modelsim6.5b linjpxt 发表于 2014-6-30 23:47
Eps是什么啊
剩余的旋转角度
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