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Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_q31.c')
-rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_q31.c | 349 |
1 files changed, 349 insertions, 0 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_q31.c b/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_q31.c new file mode 100644 index 0000000000..488cbd9a5f --- /dev/null +++ b/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_q31.c @@ -0,0 +1,349 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2013 ARM Limited. All rights reserved. +* +* $Date: 17. January 2013 +* $Revision: V1.4.1 +* +* Project: CMSIS DSP Library +* Title: arm_rfft_q31.c +* +* Description: RFFT & RIFFT Q31 process function +* +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* 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. +* -------------------------------------------------------------------- */ + +#include "arm_math.h" + +void arm_radix4_butterfly_inverse_q31( +q31_t * pSrc, +uint32_t fftLen, +q31_t * pCoef, +uint32_t twidCoefModifier); + +void arm_radix4_butterfly_q31( +q31_t * pSrc, +uint32_t fftLen, +q31_t * pCoef, +uint32_t twidCoefModifier); + +void arm_bitreversal_q31( +q31_t * pSrc, +uint32_t fftLen, +uint16_t bitRevFactor, +uint16_t * pBitRevTab); + +/*-------------------------------------------------------------------- +* Internal functions prototypes +--------------------------------------------------------------------*/ + +void arm_split_rfft_q31( + q31_t * pSrc, + uint32_t fftLen, + q31_t * pATable, + q31_t * pBTable, + q31_t * pDst, + uint32_t modifier); + +void arm_split_rifft_q31( + q31_t * pSrc, + uint32_t fftLen, + q31_t * pATable, + q31_t * pBTable, + q31_t * pDst, + uint32_t modifier); + +/** + * @addtogroup RealFFT + * @{ + */ + +/** + * @brief Processing function for the Q31 RFFT/RIFFT. + * @param[in] *S points to an instance of the Q31 RFFT/RIFFT structure. + * @param[in] *pSrc points to the input buffer. + * @param[out] *pDst points to the output buffer. + * @return none. + * + * \par Input an output formats: + * \par + * Internally input is downscaled by 2 for every stage to avoid saturations inside CFFT/CIFFT process. + * Hence the output format is different for different RFFT sizes. + * The input and output formats for different RFFT sizes and number of bits to upscale are mentioned in the tables below for RFFT and RIFFT: + * \par + * \image html RFFTQ31.gif "Input and Output Formats for Q31 RFFT" + * + * \par + * \image html RIFFTQ31.gif "Input and Output Formats for Q31 RIFFT" + */ + +void arm_rfft_q31( + const arm_rfft_instance_q31 * S, + q31_t * pSrc, + q31_t * pDst) +{ + const arm_cfft_radix4_instance_q31 *S_CFFT = S->pCfft; + + /* Calculation of RIFFT of input */ + if(S->ifftFlagR == 1u) + { + /* Real IFFT core process */ + arm_split_rifft_q31(pSrc, S->fftLenBy2, S->pTwiddleAReal, + S->pTwiddleBReal, pDst, S->twidCoefRModifier); + + /* Complex readix-4 IFFT process */ + arm_radix4_butterfly_inverse_q31(pDst, S_CFFT->fftLen, + S_CFFT->pTwiddle, + S_CFFT->twidCoefModifier); + /* Bit reversal process */ + if(S->bitReverseFlagR == 1u) + { + arm_bitreversal_q31(pDst, S_CFFT->fftLen, + S_CFFT->bitRevFactor, S_CFFT->pBitRevTable); + } + } + else + { + /* Calculation of RFFT of input */ + + /* Complex readix-4 FFT process */ + arm_radix4_butterfly_q31(pSrc, S_CFFT->fftLen, + S_CFFT->pTwiddle, S_CFFT->twidCoefModifier); + + /* Bit reversal process */ + if(S->bitReverseFlagR == 1u) + { + arm_bitreversal_q31(pSrc, S_CFFT->fftLen, + S_CFFT->bitRevFactor, S_CFFT->pBitRevTable); + } + + /* Real FFT core process */ + arm_split_rfft_q31(pSrc, S->fftLenBy2, S->pTwiddleAReal, + S->pTwiddleBReal, pDst, S->twidCoefRModifier); + } + +} + + + /** + * @} end of RealFFT group + */ + +/** + * @brief Core Real FFT process + * @param[in] *pSrc points to the input buffer. + * @param[in] fftLen length of FFT. + * @param[in] *pATable points to the twiddle Coef A buffer. + * @param[in] *pBTable points to the twiddle Coef B buffer. + * @param[out] *pDst points to the output buffer. + * @param[in] modifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table. + * @return none. + */ + +void arm_split_rfft_q31( + q31_t * pSrc, + uint32_t fftLen, + q31_t * pATable, + q31_t * pBTable, + q31_t * pDst, + uint32_t modifier) +{ + uint32_t i; /* Loop Counter */ + q31_t outR, outI; /* Temporary variables for output */ + q31_t *pCoefA, *pCoefB; /* Temporary pointers for twiddle factors */ + q31_t CoefA1, CoefA2, CoefB1; /* Temporary variables for twiddle coefficients */ + q31_t *pOut1 = &pDst[2], *pOut2 = &pDst[(4u * fftLen) - 1u]; + q31_t *pIn1 = &pSrc[2], *pIn2 = &pSrc[(2u * fftLen) - 1u]; + + /* Init coefficient pointers */ + pCoefA = &pATable[modifier * 2u]; + pCoefB = &pBTable[modifier * 2u]; + + i = fftLen - 1u; + + while(i > 0u) + { + /* + outR = (pSrc[2 * i] * pATable[2 * i] - pSrc[2 * i + 1] * pATable[2 * i + 1] + + pSrc[2 * n - 2 * i] * pBTable[2 * i] + + pSrc[2 * n - 2 * i + 1] * pBTable[2 * i + 1]); + */ + + /* outI = (pIn[2 * i + 1] * pATable[2 * i] + pIn[2 * i] * pATable[2 * i + 1] + + pIn[2 * n - 2 * i] * pBTable[2 * i + 1] - + pIn[2 * n - 2 * i + 1] * pBTable[2 * i]); */ + + CoefA1 = *pCoefA++; + CoefA2 = *pCoefA; + + /* outR = (pSrc[2 * i] * pATable[2 * i] */ + outR = ((int32_t) (((q63_t) * pIn1 * CoefA1) >> 32)); + + /* outI = pIn[2 * i] * pATable[2 * i + 1] */ + outI = ((int32_t) (((q63_t) * pIn1++ * CoefA2) >> 32)); + + /* - pSrc[2 * i + 1] * pATable[2 * i + 1] */ + outR = + (q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn1 * (-CoefA2))) >> 32); + + /* (pIn[2 * i + 1] * pATable[2 * i] */ + outI = + (q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn1++ * (CoefA1))) >> 32); + + /* pSrc[2 * n - 2 * i] * pBTable[2 * i] */ + outR = + (q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn2 * (-CoefA2))) >> 32); + CoefB1 = *pCoefB; + + /* pIn[2 * n - 2 * i] * pBTable[2 * i + 1] */ + outI = + (q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn2-- * (-CoefB1))) >> 32); + + /* pSrc[2 * n - 2 * i + 1] * pBTable[2 * i + 1] */ + outR = + (q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn2 * (CoefB1))) >> 32); + + /* pIn[2 * n - 2 * i + 1] * pBTable[2 * i] */ + outI = + (q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn2-- * (-CoefA2))) >> 32); + + /* write output */ + *pOut1++ = (outR << 1u); + *pOut1++ = (outI << 1u); + + /* write complex conjugate output */ + *pOut2-- = -(outI << 1u); + *pOut2-- = (outR << 1u); + + /* update coefficient pointer */ + pCoefB = pCoefB + (modifier * 2u); + pCoefA = pCoefA + ((modifier * 2u) - 1u); + + i--; + + } + + pDst[2u * fftLen] = pSrc[0] - pSrc[1]; + pDst[(2u * fftLen) + 1u] = 0; + + pDst[0] = pSrc[0] + pSrc[1]; + pDst[1] = 0; + +} + + +/** + * @brief Core Real IFFT process + * @param[in] *pSrc points to the input buffer. + * @param[in] fftLen length of FFT. + * @param[in] *pATable points to the twiddle Coef A buffer. + * @param[in] *pBTable points to the twiddle Coef B buffer. + * @param[out] *pDst points to the output buffer. + * @param[in] modifier twiddle coefficient modifier that supports different size FFTs with the same twiddle factor table. + * @return none. + */ + +void arm_split_rifft_q31( + q31_t * pSrc, + uint32_t fftLen, + q31_t * pATable, + q31_t * pBTable, + q31_t * pDst, + uint32_t modifier) +{ + q31_t outR, outI; /* Temporary variables for output */ + q31_t *pCoefA, *pCoefB; /* Temporary pointers for twiddle factors */ + q31_t CoefA1, CoefA2, CoefB1; /* Temporary variables for twiddle coefficients */ + q31_t *pIn1 = &pSrc[0], *pIn2 = &pSrc[(2u * fftLen) + 1u]; + + pCoefA = &pATable[0]; + pCoefB = &pBTable[0]; + + while(fftLen > 0u) + { + /* + outR = (pIn[2 * i] * pATable[2 * i] + pIn[2 * i + 1] * pATable[2 * i + 1] + + pIn[2 * n - 2 * i] * pBTable[2 * i] - + pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1]); + + outI = (pIn[2 * i + 1] * pATable[2 * i] - pIn[2 * i] * pATable[2 * i + 1] - + pIn[2 * n - 2 * i] * pBTable[2 * i + 1] - + pIn[2 * n - 2 * i + 1] * pBTable[2 * i]); + + */ + CoefA1 = *pCoefA++; + CoefA2 = *pCoefA; + + /* outR = (pIn[2 * i] * pATable[2 * i] */ + outR = ((int32_t) (((q63_t) * pIn1 * CoefA1) >> 32)); + + /* - pIn[2 * i] * pATable[2 * i + 1] */ + outI = -((int32_t) (((q63_t) * pIn1++ * CoefA2) >> 32)); + + /* pIn[2 * i + 1] * pATable[2 * i + 1] */ + outR = + (q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn1 * (CoefA2))) >> 32); + + /* pIn[2 * i + 1] * pATable[2 * i] */ + outI = + (q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn1++ * (CoefA1))) >> 32); + + /* pIn[2 * n - 2 * i] * pBTable[2 * i] */ + outR = + (q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn2 * (CoefA2))) >> 32); + + CoefB1 = *pCoefB; + + /* pIn[2 * n - 2 * i] * pBTable[2 * i + 1] */ + outI = + (q31_t) ((((q63_t) outI << 32) - ((q63_t) * pIn2-- * (CoefB1))) >> 32); + + /* pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1] */ + outR = + (q31_t) ((((q63_t) outR << 32) + ((q63_t) * pIn2 * (CoefB1))) >> 32); + + /* pIn[2 * n - 2 * i + 1] * pBTable[2 * i] */ + outI = + (q31_t) ((((q63_t) outI << 32) + ((q63_t) * pIn2-- * (CoefA2))) >> 32); + + /* write output */ + *pDst++ = (outR << 1u); + *pDst++ = (outI << 1u); + + /* update coefficient pointer */ + pCoefB = pCoefB + (modifier * 2u); + pCoefA = pCoefA + ((modifier * 2u) - 1u); + + /* Decrement loop count */ + fftLen--; + + } + + +} |