Subversion Repositories funbase_ip_library

%DCT

%DCT constant coefficient generator for sum and subtraction terms.

%Timo Alho, timo.a.alho@tut.fi

%10.6.2004

coeff_width=15; %coefficient datawidth

%all coefficients are scaled by 1/sqrt(2)

mult=2^(coeff_width-1) /sqrt(2);

%generate original coefficient matrix

N=8;

A=zeros(N, N);

j=[0:1:N-1];

A(1, :) = sqrt(1/N) * cos(0);

for i = 1:N-1

    A(i+1, :) = sqrt(2/N) * cos((2.*j+1)*i*pi/(2*N));

end

%sumterms

Asum=A(1:2:8, :);

Asum=Asum(:, 1:4);

%subterms

Asub=A(2:2:8, :);

Asub=Asub(:, 1:4);

fout=fopen('ROM_SUM', 'w');

fprintf(fout, 'TYPE Rom16x4x%i IS ARRAY (0 TO 15) OF signed(%i*4-1 downto 0);\n' , coeff_width, (coeff_width));

fprintf(fout, 'CONSTANT ROM_SUM : Rom16x4x%i := (\n', coeff_width);

for a3=0:1

    for a2=0:1

        for a1=0:1

            for a0=0:1

                Y0 = Asum(1,1)*a0 + Asum(1,2)*a1 + Asum(1,3)*a2 + Asum(1,4)*a3;

                Y1 = Asum(2,1)*a0 + Asum(2,2)*a1 + Asum(2,3)*a2 + Asum(2,4)*a3;

                Y2 = Asum(3,1)*a0 + Asum(3,2)*a1 + Asum(3,3)*a2 + Asum(3,4)*a3;

                Y3 = Asum(4,1)*a0 + Asum(4,2)*a1 + Asum(4,3)*a2 + Asum(4,4)*a3;

                Y0=round(mult*Y0);

                Y1=round(mult*Y1);

                Y2=round(mult*Y2);

                Y3=round(mult*Y3);

                if (Y0 == 2^(coeff_width-1))

                    Y0 = Y0 - 1;

                end

                if (Y1 == 2^(coeff_width-1))

                    Y1 = Y1 - 1;

                end

                if (Y2 == 2^(coeff_width-1))

                    Y2 = Y2 - 1;

                end

                if (Y3 == 2^(coeff_width-1))

                    Y3 = Y3 - 1;

                end

                fprintf(fout, 'conv_signed(%i, %i) & conv_signed(%i, %i) & conv_signed(%i, %i) & conv_signed(%i, %i),\n', Y0, coeff_width, Y1, coeff_width, Y2, coeff_width, Y3, coeff_width);

            end

        end

    end

end

fprintf(fout, 'REMOVE THIS, AND LAST dot\n);\n');

fclose(fout);

fout=fopen('ROM_SUB', 'w');

fprintf(fout, 'TYPE Rom16x4x%i IS ARRAY (0 TO 15) OF signed(%i*4-1 downto 0);\n' , coeff_width, (coeff_width));

fprintf(fout, 'CONSTANT ROM_SUB : Rom16x4x%i := (\n', coeff_width);

for a3=0:1

    for a2=0:1

        for a1=0:1

            for a0=0:1

                Y0 = Asub(1,1)*a0 + Asub(1,2)*a1 + Asub(1,3)*a2 + Asub(1,4)*a3;

                Y1 = Asub(2,1)*a0 + Asub(2,2)*a1 + Asub(2,3)*a2 + Asub(2,4)*a3;

                Y2 = Asub(3,1)*a0 + Asub(3,2)*a1 + Asub(3,3)*a2 + Asub(3,4)*a3;

                Y3 = Asub(4,1)*a0 + Asub(4,2)*a1 + Asub(4,3)*a2 + Asub(4,4)*a3;

                Y0=round(mult*Y0);

                Y1=round(mult*Y1);

                Y2=round(mult*Y2);

                Y3=round(mult*Y3);

                if (Y0 == 2^(coeff_width-1))

                    Y0 = Y0 - 1;

                end

                if (Y1 == 2^(coeff_width-1))

                    Y1 = Y1 - 1;

                end

                if (Y2 == 2^(coeff_width-1))

                    Y2 = Y2 - 1;

                end

                if (Y3 == 2^(coeff_width-1))

                    Y3 = Y3 - 1;

                end

                fprintf(fout, 'conv_signed(%i, %i) & conv_signed(%i, %i) & conv_signed(%i, %i) & conv_signed(%i, %i),\n', Y0, coeff_width, Y1, coeff_width, Y2, coeff_width, Y3, coeff_width);

            end

        end

    end

end

fprintf(fout, 'REMOVE THIS, AND LAST dot\n);\n');

fclose(fout);