32343
843447835d
- IPS200 display menu with real-time status and parameter settings - Camera image processing and line tracking - IMU attitude solution and PID control - WiFi SPI oscilloscope data transmission
116 lines
4.4 KiB
C
116 lines
4.4 KiB
C
/**
|
|
* \file Ifx_FftF32.h
|
|
* \brief Floating-point Fast Fourier Transform
|
|
* \ingroup library_srvsw_sysse_math_f32_fft
|
|
*
|
|
*
|
|
*
|
|
* \version disabled
|
|
* \copyright Copyright (c) 2013 Infineon Technologies AG. All rights reserved.
|
|
*
|
|
*
|
|
* IMPORTANT NOTICE
|
|
*
|
|
*
|
|
* Use of this file is subject to the terms of use agreed between (i) you or
|
|
* the company in which ordinary course of business you are acting and (ii)
|
|
* Infineon Technologies AG or its licensees. If and as long as no such
|
|
* terms of use are agreed, use of this file is subject to following:
|
|
|
|
|
|
* Boost Software License - Version 1.0 - August 17th, 2003
|
|
|
|
* Permission is hereby granted, free of charge, to any person or
|
|
* organization obtaining a copy of the software and accompanying
|
|
* documentation covered by this license (the "Software") to use, reproduce,
|
|
* display, distribute, execute, and transmit the Software, and to prepare
|
|
* derivative works of the Software, and to permit third-parties to whom the
|
|
* Software is furnished to do so, all subject to the following:
|
|
|
|
* The copyright notices in the Software and this entire statement, including
|
|
* the above license grant, this restriction and the following disclaimer, must
|
|
* be included in all copies of the Software, in whole or in part, and all
|
|
* derivative works of the Software, unless such copies or derivative works are
|
|
* solely in the form of machine-executable object code generated by a source
|
|
* language processor.
|
|
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
|
|
* SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
|
|
* FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
|
|
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
|
|
* DEALINGS IN THE SOFTWARE.
|
|
|
|
*
|
|
* \defgroup library_srvsw_sysse_math_f32_fft Floating-point FFT
|
|
* This module implements the Fast Fourier Transform in single precision floating-point
|
|
* \ingroup library_srvsw_sysse_math_f32
|
|
*
|
|
*/
|
|
|
|
#ifndef IFX_FFTF32_H
|
|
#define IFX_FFTF32_H
|
|
|
|
#include "Ifx_Cf32.h"
|
|
|
|
/** \brief Maximum FFT resolution (bits).
|
|
* If redefined, then \ref Ifx_g_FftF32_bitReverseTable and \ref Ifx_g_FftF32_twiddleTable shall be regenerated. */
|
|
#define IFX_FFTF32_MAX_RESOLUTION (14)
|
|
|
|
/** \brief Maximum FFT length.
|
|
* If redefined, then \ref Ifx_g_FftF32_bitReverseTable and \ref Ifx_g_FftF32_twiddleTable shall be regenerated. */
|
|
#define IFX_FFTF32_MAX_LENGTH (1U << IFX_FFTF32_MAX_RESOLUTION)
|
|
|
|
/** \brief Bit reversal table */
|
|
IFX_EXTERN IFX_CONST uint16 Ifx_g_FftF32_bitReverseTable[IFX_FFTF32_MAX_LENGTH];
|
|
|
|
/** \brief Twiddle factor table */
|
|
IFX_EXTERN IFX_CONST cfloat32 Ifx_g_FftF32_twiddleTable[IFX_FFTF32_MAX_LENGTH / 2];
|
|
|
|
//----------------------------------------------------------------------------------------
|
|
/** \addtogroup library_srvsw_sysse_math_f32_fft
|
|
* \{ */
|
|
|
|
/** \name Transform functions
|
|
* \{ */
|
|
|
|
/** \brief Twiddle factor generator */
|
|
IFX_EXTERN cfloat32 *Ifx_FftF32_generateTwiddleFactor(cfloat32 *TF, sint16 nX);
|
|
|
|
/** \brief Radix-2 Fast-Fourier Transform */
|
|
IFX_EXTERN cfloat32 *Ifx_FftF32_radix2(cfloat32 *R, const cfloat32 *X, uint16 nX);
|
|
|
|
/** \brief Radix-2 Inverse Fast-Fourier Transform */
|
|
IFX_EXTERN cfloat32 *Ifx_FftF32_radix2I(cfloat32 *R, const cfloat32 *X, uint16 nX);
|
|
|
|
/** \} */
|
|
//----------------------------------------------------------------------------------------
|
|
/** \name Utility functions
|
|
* \{ */
|
|
|
|
/** \brief Lookup from \ref Ifx_g_FftF32_bitReverseTable the bit-reversed \<n\> with \<bits\> as number of bits */
|
|
IFX_INLINE uint16 Ifx_FftF32_lookUpReversedBits(uint16 n, unsigned bits)
|
|
{
|
|
unsigned shift = IFX_FFTF32_MAX_RESOLUTION - bits;
|
|
uint16 index = Ifx_g_FftF32_bitReverseTable[n];
|
|
return index >> shift;
|
|
}
|
|
|
|
|
|
/** \brief Lookup from \ref Ifx_g_FftF32_twiddleTable the twiddle factor for N, k */
|
|
IFX_INLINE cfloat32 Ifx_FftF32_lookUpTwiddleFactor(sint32 N, sint32 k)
|
|
{
|
|
return Ifx_g_FftF32_twiddleTable[k * IFX_FFTF32_MAX_LENGTH / N];
|
|
}
|
|
|
|
|
|
/** \brief Calculate the bit-reversed \<n\> with \<bits\> as number of bits */
|
|
IFX_EXTERN uint16 Ifx_FftF32_reverseBits(uint16 n, unsigned bits);
|
|
|
|
/** \} */
|
|
//----------------------------------------------------------------------------------------
|
|
/** \} */
|
|
|
|
#endif /* IFX_FFTF32_H */
|