fft_32k_tb.m

FFT 32k use VHDL MATLAB

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% file : fft_32K_tb.m
%
% Description : The following Matlab testbench excercises the Altera FFT Model fft_small_model.m
% generated by Altera's FFT Megacore and outputs results to text files.
%
% Copyright (C) 1988-2005 Altera Corporation                                                
% Parameterization Space    
N=16384;
num_frames = 2;
% Read input complex vector from source text files 
fidr = fopen('..\source\real_input.txt','r');                                            
fidi = fopen('..\source\imag_input.txt','r');  
foreal = fopen('..\source\real_output_ver.txt', 'r');
foimag = fopen('..\source\imag_output_ver.txt', 'r');
foexp = fopen('..\source\exponent_output_ver.txt', 'r');
xreali=fscanf(fidr,'%d');                                                      
ximagi=fscanf(fidi,'%d');                   
fftrealo = fscanf(foreal,'%d');
fftimago = fscanf(foimag,'%d');
fftexpo = fscanf(foexp, '%d');
fclose(fidi);                                                                  
fclose(fidr);                                                                  
% Create input complex row vector from source text files 
x = xreali' + j*ximagi'; 

num_sample = max(size(x));
top_i = 1;
bot_i = 1;


for i=1:num_sample
    if (mod(i,2) == 0)
        x_bot(bot_i) = x(i);
        bot_i = bot_i + 1;
    else
        x_top(top_i) = x(i);
        top_i = top_i + 1;
    end
end

for i=1:num_frames
    [y_top((i-1)*N+1:i*N), exp_out_top((i-1)*N+1:i*N)] = fft_small_model(x_top((i-1)*N+1:i*N),N,0); 
    [y_bot((i-1)*N+1:i*N), exp_out_bot((i-1)*N+1:i*N)] = fft_small_model(x_bot((i-1)*N+1:i*N),N,0); 
end

for k=1:num_frames
    for i=1:N
        op_bot((k-1)*2*N+i) = floor((y_bot((k-1)*N+i) * twiddle(i)) / 2^15);
        op_top((k-1)*2*N+i) = y_top((k-1)*N+i);
        final_fft((k-1)*2*N+i) = op_bot((k-1)*2*N+i) + op_top((k-1)*2*N+i);
    end
end

for k=1:num_frames
    for i=N+1:2*N
        op_bot((k-1)*2*N+i) = floor((y_bot((k-1)*N+i-N) * twiddle(i)) / 2^15);
        op_top((k-1)*2*N+i) = y_top((k-1)*N+i-N);
        final_fft((k-1)*2*N+i) = op_bot((k-1)*2*N+i) + op_top((k-1)*2*N+i);
    end
end


%compare fft_real_out
for k=1:num_frames
    for i=1:N*2
        comp_real((k-1)*2*N+i,1) = fftrealo((k-1)*2*N+i);
        comp_real((k-1)*2*N+i,2) = real(final_fft((k-1)*2*N+i));
    end
end

error_real = isequal(comp_real(:,1), comp_real(:,2));

%compare fft_imag_out
for k=1:num_frames
    for i=1:N*2
        comp_imag((k-1)*2*N+i,1) = fftimago((k-1)*2*N+i);
        comp_imag((k-1)*2*N+i,2) = imag(final_fft((k-1)*2*N+i));
    end
end

error_imag = isequal(comp_imag(:,1), comp_imag(:,2));

if (error_real==1 && error_imag==1)
    disp('Simulation passes - Results Match');
else
    disp('Simulation fails - Results Mismatch');
end