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Diffstat (limited to 'DSP_Lib/Examples/arm_fir_example/ARM/arm_fir_example_f32.c')
-rw-r--r-- | DSP_Lib/Examples/arm_fir_example/ARM/arm_fir_example_f32.c | 233 |
1 files changed, 0 insertions, 233 deletions
diff --git a/DSP_Lib/Examples/arm_fir_example/ARM/arm_fir_example_f32.c b/DSP_Lib/Examples/arm_fir_example/ARM/arm_fir_example_f32.c deleted file mode 100644 index 58dfb47..0000000 --- a/DSP_Lib/Examples/arm_fir_example/ARM/arm_fir_example_f32.c +++ /dev/null @@ -1,233 +0,0 @@ -/* ---------------------------------------------------------------------- - * Copyright (C) 2010-2012 ARM Limited. All rights reserved. - * -* $Date: 17. January 2013 -* $Revision: V1.4.0 -* -* Project: CMSIS DSP Library - * Title: arm_fir_example_f32.c - * - * Description: Example code demonstrating how an FIR filter can be used - * as a low pass filter. - * - * Target Processor: Cortex-M4/Cortex-M3 - * -* Redistribution and use in source and binary forms, with or without -* modification, are permitted provided that the following conditions -* are met: -* - Redistributions of source code must retain the above copyright -* notice, this list of conditions and the following disclaimer. -* - Redistributions in binary form must reproduce the above copyright -* notice, this list of conditions and the following disclaimer in -* the documentation and/or other materials provided with the -* distribution. -* - Neither the name of ARM LIMITED nor the names of its contributors -* may be used to endorse or promote products derived from this -* software without specific prior written permission. -* -* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS -* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE -* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, -* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, -* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; -* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER -* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT -* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN -* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -* POSSIBILITY OF SUCH DAMAGE. - * -------------------------------------------------------------------- */ - -/** - * @ingroup groupExamples - */ - -/** - * @defgroup FIRLPF FIR Lowpass Filter Example - * - * \par Description: - * \par - * Removes high frequency signal components from the input using an FIR lowpass filter. - * The example demonstrates how to configure an FIR filter and then pass data through - * it in a block-by-block fashion. - * \image html FIRLPF_signalflow.gif - * - * \par Algorithm: - * \par - * The input signal is a sum of two sine waves: 1 kHz and 15 kHz. - * This is processed by an FIR lowpass filter with cutoff frequency 6 kHz. - * The lowpass filter eliminates the 15 kHz signal leaving only the 1 kHz sine wave at the output. - * \par - * The lowpass filter was designed using MATLAB with a sample rate of 48 kHz and - * a length of 29 points. - * The MATLAB code to generate the filter coefficients is shown below: - * <pre> - * h = fir1(28, 6/24); - * </pre> - * The first argument is the "order" of the filter and is always one less than the desired length. - * The second argument is the normalized cutoff frequency. This is in the range 0 (DC) to 1.0 (Nyquist). - * A 6 kHz cutoff with a Nyquist frequency of 24 kHz lies at a normalized frequency of 6/24 = 0.25. - * The CMSIS FIR filter function requires the coefficients to be in time reversed order. - * <pre> - * fliplr(h) - * </pre> - * The resulting filter coefficients and are shown below. - * Note that the filter is symmetric (a property of linear phase FIR filters) - * and the point of symmetry is sample 14. Thus the filter will have a delay of - * 14 samples for all frequencies. - * \par - * \image html FIRLPF_coeffs.gif - * \par - * The frequency response of the filter is shown next. - * The passband gain of the filter is 1.0 and it reaches 0.5 at the cutoff frequency 6 kHz. - * \par - * \image html FIRLPF_response.gif - * \par - * The input signal is shown below. - * The left hand side shows the signal in the time domain while the right hand side is a frequency domain representation. - * The two sine wave components can be clearly seen. - * \par - * \image html FIRLPF_input.gif - * \par - * The output of the filter is shown below. The 15 kHz component has been eliminated. - * \par - * \image html FIRLPF_output.gif - * - * \par Variables Description: - * \par - * \li \c testInput_f32_1kHz_15kHz points to the input data - * \li \c refOutput points to the reference output data - * \li \c testOutput points to the test output data - * \li \c firStateF32 points to state buffer - * \li \c firCoeffs32 points to coefficient buffer - * \li \c blockSize number of samples processed at a time - * \li \c numBlocks number of frames - * - * \par CMSIS DSP Software Library Functions Used: - * \par - * - arm_fir_init_f32() - * - arm_fir_f32() - * - * <b> Refer </b> - * \link arm_fir_example_f32.c \endlink - * - */ - - -/** \example arm_fir_example_f32.c - */ - -/* ---------------------------------------------------------------------- -** Include Files -** ------------------------------------------------------------------- */ - -#include "arm_math.h" -#include "math_helper.h" - -/* ---------------------------------------------------------------------- -** Macro Defines -** ------------------------------------------------------------------- */ - -#define TEST_LENGTH_SAMPLES 320 -#define SNR_THRESHOLD_F32 140.0f -#define BLOCK_SIZE 32 -#define NUM_TAPS 29 - -/* ------------------------------------------------------------------- - * The input signal and reference output (computed with MATLAB) - * are defined externally in arm_fir_lpf_data.c. - * ------------------------------------------------------------------- */ - -extern float32_t testInput_f32_1kHz_15kHz[TEST_LENGTH_SAMPLES]; -extern float32_t refOutput[TEST_LENGTH_SAMPLES]; - -/* ------------------------------------------------------------------- - * Declare Test output buffer - * ------------------------------------------------------------------- */ - -static float32_t testOutput[TEST_LENGTH_SAMPLES]; - -/* ------------------------------------------------------------------- - * Declare State buffer of size (numTaps + blockSize - 1) - * ------------------------------------------------------------------- */ - -static float32_t firStateF32[BLOCK_SIZE + NUM_TAPS - 1]; - -/* ---------------------------------------------------------------------- -** FIR Coefficients buffer generated using fir1() MATLAB function. -** fir1(28, 6/24) -** ------------------------------------------------------------------- */ - -const float32_t firCoeffs32[NUM_TAPS] = { - -0.0018225230f, -0.0015879294f, +0.0000000000f, +0.0036977508f, +0.0080754303f, +0.0085302217f, -0.0000000000f, -0.0173976984f, - -0.0341458607f, -0.0333591565f, +0.0000000000f, +0.0676308395f, +0.1522061835f, +0.2229246956f, +0.2504960933f, +0.2229246956f, - +0.1522061835f, +0.0676308395f, +0.0000000000f, -0.0333591565f, -0.0341458607f, -0.0173976984f, -0.0000000000f, +0.0085302217f, - +0.0080754303f, +0.0036977508f, +0.0000000000f, -0.0015879294f, -0.0018225230f -}; - -/* ------------------------------------------------------------------ - * Global variables for FIR LPF Example - * ------------------------------------------------------------------- */ - -uint32_t blockSize = BLOCK_SIZE; -uint32_t numBlocks = TEST_LENGTH_SAMPLES/BLOCK_SIZE; - -float32_t snr; - -/* ---------------------------------------------------------------------- - * FIR LPF Example - * ------------------------------------------------------------------- */ - -int32_t main(void) -{ - uint32_t i; - arm_fir_instance_f32 S; - arm_status status; - float32_t *inputF32, *outputF32; - - /* Initialize input and output buffer pointers */ - inputF32 = &testInput_f32_1kHz_15kHz[0]; - outputF32 = &testOutput[0]; - - /* Call FIR init function to initialize the instance structure. */ - arm_fir_init_f32(&S, NUM_TAPS, (float32_t *)&firCoeffs32[0], &firStateF32[0], blockSize); - - /* ---------------------------------------------------------------------- - ** Call the FIR process function for every blockSize samples - ** ------------------------------------------------------------------- */ - - for(i=0; i < numBlocks; i++) - { - arm_fir_f32(&S, inputF32 + (i * blockSize), outputF32 + (i * blockSize), blockSize); - } - - /* ---------------------------------------------------------------------- - ** Compare the generated output against the reference output computed - ** in MATLAB. - ** ------------------------------------------------------------------- */ - - snr = arm_snr_f32(&refOutput[0], &testOutput[0], TEST_LENGTH_SAMPLES); - - if (snr < SNR_THRESHOLD_F32) - { - status = ARM_MATH_TEST_FAILURE; - } - else - { - status = ARM_MATH_SUCCESS; - } - - /* ---------------------------------------------------------------------- - ** Loop here if the signal does not match the reference output. - ** ------------------------------------------------------------------- */ - - if( status != ARM_MATH_SUCCESS) - { - while(1); - } - - while(1); /* main function does not return */ -} - -/** \endlink */ |