Verify FIR Filter on ARM Cortex-A Processor in MATLAB
This example shows how to use the Code Replacement Library (CRL) for ARM Cortex-A processor with DSP System Toolbox™. The example uses a dsp.FIRFilter
(DSP System Toolbox) object to filter two sine waves of different frequencies.
Setup and Simulate
1. Open the ex_fir_ne10_tut_ml
example function, which implements a lowpass FIR filter object.
function y1 = ex_fir_ne10_tut_ml(u1) % Copyright 2014-2022 The MathWorks, Inc. persistent fir; if isempty(fir) fir = dsp.FIRFilter('Numerator', fir1(63, 0.33)); end y1 = fir(u1); end
2. Create two sine wave signals with 1 KHz and 3 KHz frequencies, respectively.
sin1 = dsp.SineWave('Amplitude',1,'Frequency',1000,... 'SampleRate',8000, 'SamplesPerFrame', 76,... 'OutputDataType', 'single'); sin2 = dsp.SineWave('Amplitude',4,'Frequency',3000,... 'SampleRate',8000, 'SamplesPerFrame', 76,... 'OutputDataType', 'single');
3. Create a spectrum analyzer to view the spectrum of the input and filtered output.
scope = spectrumAnalyzer('SampleRate',8e3,'ShowLegend',true,... 'PlotAsTwoSidedSpectrum', false, ... 'RBWSource', 'Property',... 'RBW',8000/260, 'Window','Kaiser', ... 'OverlapPercent', 80,... 'YLimits', [-76 56], 'SpectralAverages',10);
4. Simulate the example
NN = 2000; for k = 1:NN x1k = sin1(); % generate 1K Hz sine wave x3k = sin2(); % generate 3K Hz sine wave n1 = randn(size(x1k), 'single')*sqrt(.05); % generate noise signal u1 = x1k+x3k+n1; y1 = ex_fir_ne10_tut_ml(u1); scope([u1,y1]); end
Configure for Code Replacement
1. Create a code generation configuration object for use with codegen when generating a C/C++ static library.
cfg = coder.config( "lib", "ecoder", true ); cfg.GenCodeOnly = true; cfg.CodeReplacementLibrary = "GCC ARM Cortex-A"; cfg.HardwareImplementation.ProdHWDeviceType = "ARM Compatible->ARM Cortex-A";
2. Open the Custom Code panel of the configuration dialog and verify the settings.
cfg.dialog
Generate Code
1. Generate C code for the MATLAB function ex_fir_ne10_tut_ml
.
codegen ex_fir_ne10_tut_ml -args single(0) -config cfg -report
Code generation successful: View report
2. When code generation completes, click View report to display the code generation report.
3. Click on the ex_fir_ne10_tut_ml.c
file. The code includes the calls to the accelerated NE10 functions, ne10_fir_init_float and ne10_fir_float_neon in the ex_fir_ne10_tut_ml function.
... float ex_fir_ne10_tut_ml(float u1) { ... if (fir.isInitialized != 1) { ... ne10_fir_init_float(&fir.cSFunObject.S, 64U, &fir.cSFunObject.qCoeff[0], &fir.cSFunObject.pState[0], 1U); } ... ne10_fir_float_neon(&fir.cSFunObject.S, &U0, &b_y1, 1U); ... } ...
4. Optionally, the generated code can be compiled and executed on ARM Cortex-A target by using an appropriate toolchain.