dds_001.rar_DDS MATLAB_acceldsp

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % AccelDSP 10.1. build 1134 production, compiled 2008-02-12 % % THIS IS UNPUBLISHED, LICENSED SOFTWARE THAT IS THE CONFIDENTIAL % AND PROPRIETARY PROPERTY OF XILINX OR ITS LICENSORS % % Copyright(c) Xilinx, Inc., 2000-2008, All Rights Reserved. % Reproduction or reuse, in any form, without the explicit written % consent of Xilinx, Inc., is strictly prohibited. % % User: why % Machine: BUPT-5461E3D393 (i1586, Windows XP Service Pack 2, 5.01.2600) % Date: Mon Jun 16 09:28:40 2008 % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % AccelWare Function: DDS % AccelDSP Version: 10.1. build 1134 production %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% qFA = quantizer( 'ufixed', 'floor', 'wrap', [ 22 0 ] ); qout = quantizer( 'fixed', 'floor', 'wrap', [ 10 8 ] ); qLoop=quantizer('ufixed','floor','wrap',[32 0]); warning off Latency = 1; DDS_Frequency = 4;% MHz DesiredFreq = 0; % MHz PhaseIn = floor(DesiredFreq/DDS_Frequency*2^22); if(rem(DesiredFreq,1) == 0) ConstGain = 1; else ConstGain = round(1/rem(DesiredFreq,1)); end %N_SAMPLES = 0; % NOTE: If the desired frequency is changed N_SAMPLES should be updated with the equation below... N_SAMPLES = lcm(DDS_Frequency*ConstGain,DesiredFreq*ConstGain)/ConstGain; if (N_SAMPLES>10000) contSim = menu(['Required Samples ' num2str(N_SAMPLES) '-- This could take a long time'],'Continue','Stop'); else contSim = 1; end if(contSim == 1) PhaseStream = quantize(qFA,ones(1,N_SAMPLES+Latency)*PhaseIn); for n = 1:N_SAMPLES+Latency [Sine_All(n),Cosine_All(n)] = dds_001(PhaseStream(n)); end PhaseStreamSum=cumsum(PhaseStream); inRad=PhaseStreamSum*2*pi/(2^qFA.Format(1)); inRad = mod(inRad(1:end-Latency),2*pi); fig = figure; set(fig,'Units','normalized'); upos = [0.1 0.1 0.75 0.8]; set(fig,'Position',upos); set(fig,'Name','AccelWare::'); set(fig,'NumberTitle','off'); ha=axes('pos',[0 1 1 1],'visible','off','Tag','suptitle'); ht=text(0.5,-0.04,'Direct Digital Synthesizer (DDS)');set(ht,'horizontalalignment','center','fontsize',16,'color','b'); set(ht,'Interpreter','none'); streamSinOut=Sine_All(Latency+1:end); vecerror_sin = streamSinOut-sin(inRad); streamCosOut=Cosine_All(Latency+1:end); vecerror_cos = streamCosOut-cos(inRad); subplot(3,2,1) hold off; plot(inRad,sin(inRad),'.') hold on; plot(inRad,streamSinOut,'r.') grid on; xlabel('x (Radians)'); ylabel('sin(x)'); legend('Matlab','AccelWare'); legend('boxoff') subplot(3,2,3) hold off; plot(inRad,vecerror_sin) hold on; plot(inRad,ones(size(vecerror_sin))*2^-qout.Format(2),'g-','LineWidth',2); plot(inRad,-ones(size(vecerror_sin))*2^-qout.Format(2),'g-','LineWidth',2); grid on; xlabel('x (Radians)'); ylabel('AccelWare-Matlab'); title('Error against Matlabs built in functions'); LSBError = sprintf('1-LSB Error: %3.2e',2^-qout.Format(2)); legend('Error against sin(x)',LSBError) legend('boxoff') subplot(3,2,5) hold off; tempFFT=abs(fft(streamSinOut,N_SAMPLES)); temp2=sort(tempFFT); loc=find(tempFFT==0); minNonZero=find(temp2>0); if(~isempty(minNonZero)) tempFFT(loc)=temp2(minNonZero(1))*1e-5; % fill in zeros with 100dB below first spur end plot(linspace(0,1,N_SAMPLES),20*log10(tempFFT)) hold on; plot(linspace(0,1,N_SAMPLES),max(20*log10(tempFFT))+20*log10(2^--1),'y','LineWidth',2) plot(linspace(0,1,N_SAMPLES),max(20*log10(tempFFT))+20*log10(2^--1),'g','LineWidth',2) grid on; tooClose = 1; locC=find(tempFFT == temp2(end-1)); offSet=2; while (tooClose) loc2=find(tempFFT == temp2(end-offSet)); if (abs(locC-loc2)<=2) offSet = offSet+1; else tooClose = 0; end end tempString=sprintf('%s','Sine Spurious Free Range: ', num2str(20*log10(temp2(end-1)/temp2(end-offSet))), 'dB'); title(['FFT - ' tempString]); legend('Sine','Noise floor from input quantization','Noise floor from output quantization','location','northeast'); legend('boxoff') plot(loc2/N_SAMPLES,20*log10(tempFFT(loc2)),'ro') axis([0 0.5 20*log10(temp2(end-offSet)*1e-3) 20*log10(temp2(end)*10)]); subplot(3,2,2) hold off; plot(inRad,cos(inRad),'.') hold on; plot(inRad,streamCosOut,'r.') grid on; xlabel('x (Radians)'); ylabel('cos(x)'); legend('Matlab','AccelWare'); legend('boxoff') subplot(3,2,4) hold off; plot(inRad,vecerror_cos) hold on; plot(inRad,ones(size(vecerror_cos))*2^-qout.Format(2),'g-','LineWidth',2); plot(inRad,-ones(size(vecerror_cos))*2^-qout.Format(2),'g-','LineWidth',2); grid on; xlabel('x (Radians)'); ylabel('AccelWare-Matlab'); title('Error against Matlabs built in functions'); LSBError = sprintf('1-LSB Error: %3.2e',2^-qout.Format(2)); legend('Error against cos(x)',LSBError) legend('boxoff') subplot(3,2,6) hold off; tempFFT=abs(fft(streamCosOut,N_SAMPLES)); temp2=sort(tempFFT); loc=find(tempFFT==0); minNonZero=find(temp2>0); if(~isempty(minNonZero)) tempFFT(loc)=temp2(minNonZero(1))*1e-5; % fill in zeros with 100dB below first spur end plot(linspace(0,1,N_SAMPLES),20*log10(tempFFT)) hold on; plot(linspace(0,1,N_SAMPLES),max(20*log10(tempFFT))+20*log10(2^--1),'y','LineWidth',2) plot(linspace(0,1,N_SAMPLES),max(20*log10(tempFFT))+20*log10(2^--1),'g','LineWidth',2) grid on; tooClose = 1; locC=find(tempFFT == temp2(end-1)); offSet=2; while (tooClose) loc2=find(tempFFT == temp2(end-offSet)); if (abs(locC-loc2)<=2) offSet = offSet+1; else tooClose = 0; end end tempString=sprintf('%s','Cosine Spurious Free Range: ', num2str(20*log10(temp2(end-1)/temp2(end-offSet))), 'dB'); title(['FFT - ' tempString]); legend('Cosine','Noise floor from input quantization','Noise floor from output quantization','location','northeast'); legend('boxoff') plot(loc2/N_SAMPLES,20*log10(tempFFT(loc2)),'ro') axis([0 0.5 20*log10(temp2(end-offSet)*1e-3) 20*log10(temp2(end)*10)]); end