fft_complex.m

ADI TS系列的DSP FFT源代码

%_______________________________________________________________________
% FFT_COMPLEX.M          Matlab script to plot ADSP-TS201 FFT results
%
%_______________________________________________________________________

clear all;
close all;

%please introduce here the number X from the assembly program. 
%Nothing else is to be done. X=2*number of complex points
N='1024';

Number_points=num2str(str2num(N)*2);

input_file=['inputs/input',Number_points,'.dat'];
output_file=['outputs/output_cplx_',N,'.dat'];
output_matlab_file=['outputs/output_cplx_',N,'_matlab.dat'];


%//load input file from generated random value.
        fid = fopen(input_file, 'r');
            [a, count] = fscanf (fid, '%f%c');
        fclose(fid);
        %I have to eliminate the comma that is written after each input number

        for i=1:size(a)/2
            input(i,1)=a(2*i-1);
        end;

                    %//input is NOT complex, so the point of FFT must be halved.
N1=length(input)/2;  %//get the length of input file and point for FFT.
FFT_point=N1
j=sqrt(-1);
for i=1:N1
    inreal(i)=input(2*i-1);
    inimag(i)=input(2*i);
end
incomplex=inreal+(inimag*j);
incplx=fft(incomplex,N1);    %//FFT of input.

    fin = fopen(output_matlab_file, 'wt');
        for i=1:N1
          fprintf(fin, '%g\n%g\n', real(incplx(1,i)), imag(incplx(1,i)));
        end;
    fclose(fin);




output=load (output_file);      %//load file output of optimized FFT for TigerSHARC TS-101.
                                %//output of optimized FFT for TigerSHARC TS-101.
for k=1:N1
    outreal(k)=output(2*k-1);
    outimag(k)=output(2*k);
end
outcplx=outreal+(outimag*j);

y=0:1/N1:1-1/N1;
mlb=20*log10(abs(incplx));
%chip=20*log10(sqrt((outreal.*outreal)+(outimag.*outimag)));
chip=20*log10(abs(outcplx));

figure
subplot(2,2,1);
plot(y,abs(incomplex))      %//plot input data.
grid
title([num2str(FFT_point),' Complex Input data'])

%subplot(2,2,2);
%plot(y,outcplx,'r',y,incplx,'g')    %//plot comparison of FFT TigerSHARC vs MATLAB.
%grid
%title(['Output of ',num2str(FFT_point),' point FFT, TS in green')

subplot(2,2,2);
plot(y,mlb,'r',y,chip,'g')      %//plot Log Magnitude comparison TigerSHARC vs MATLAB.
grid
title('Log Magnitude Comparison, TS in green')

subplot(2,2,3);
plot(y,abs(incplx),'r',y,abs(outcplx),'g')  %//plot Magnitude comparison TigerSHARC vs MATLAB.
grid
title('Magnitude Comparison, TS in green')

subplot(2,2,4);
plot(y,abs(incplx)-(abs(outcplx)))    %//plot Error Magnitude TigerSHARC vs MATLAB.
grid
title('Error in Magnitude')

figure
subplot(2,2,1);
plot(y,real(incplx),'r',y,outreal,'g')
grid
title('Real Part Comparison, TS in green')
subplot(2,2,2);
plot(y,real(incplx)-outreal)
grid
title('Error in Real')
subplot(2,2,3);
plot(y,imag(incplx),'r',y,outimag,'g')
grid
title('Imaginary Part Comparison, TS in green')
subplot(2,2,4);
plot(y,imag(incplx)-outimag)
grid
title('Error in Imaginary')