From 86608c6770cf08c138a2bdab5855072f64be09ef Mon Sep 17 00:00:00 2001 From: joshua Date: Sat, 30 Dec 2023 23:54:31 -0500 Subject: initial commit --- .../DSP/Source/TransformFunctions/arm_rfft_q31.c | 292 +++++++++++++++++++++ 1 file changed, 292 insertions(+) create mode 100644 Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_q31.c (limited to 'Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_q31.c') diff --git a/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_q31.c b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_q31.c new file mode 100644 index 0000000..0cc595b --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_rfft_q31.c @@ -0,0 +1,292 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_rfft_q31.c + * Description: FFT & RIFFT Q31 process function + * + * $Date: 18. March 2019 + * $Revision: V1.6.0 + * + * Target Processor: Cortex-M cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2019 ARM Limited or its affiliates. All rights reserved. + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the License); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an AS IS BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "arm_math.h" + +/* ---------------------------------------------------------------------- + * Internal functions prototypes + * -------------------------------------------------------------------- */ + +void arm_split_rfft_q31( + q31_t * pSrc, + uint32_t fftLen, + const q31_t * pATable, + const q31_t * pBTable, + q31_t * pDst, + uint32_t modifier); + +void arm_split_rifft_q31( + q31_t * pSrc, + uint32_t fftLen, + const q31_t * pATable, + const 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 input buffer + @param[out] pDst points to output buffer + @return none + + @par Input an output formats + 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_instance_q31 *S_CFFT = S->pCfft; + uint32_t L2 = S->fftLenReal >> 1U; + uint32_t i; + + /* Calculation of RIFFT of input */ + if (S->ifftFlagR == 1U) + { + /* Real IFFT core process */ + arm_split_rifft_q31 (pSrc, L2, S->pTwiddleAReal, S->pTwiddleBReal, pDst, S->twidCoefRModifier); + + /* Complex IFFT process */ + arm_cfft_q31 (S_CFFT, pDst, S->ifftFlagR, S->bitReverseFlagR); + + for(i = 0; i < S->fftLenReal; i++) + { + pDst[i] = pDst[i] << 1U; + } + } + else + { + /* Calculation of RFFT of input */ + + /* Complex FFT process */ + arm_cfft_q31 (S_CFFT, pSrc, S->ifftFlagR, S->bitReverseFlagR); + + /* Real FFT core process */ + arm_split_rfft_q31 (pSrc, L2, S->pTwiddleAReal, S->pTwiddleBReal, pDst, S->twidCoefRModifier); + } + +} + +/** + @} end of RealFFT group + */ + +/** + @brief Core Real FFT process + @param[in] pSrc points to input buffer + @param[in] fftLen length of FFT + @param[in] pATable points to twiddle Coef A buffer + @param[in] pBTable points to twiddle Coef B buffer + @param[out] pDst points to 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, + const q31_t * pATable, + const q31_t * pBTable, + q31_t * pDst, + uint32_t modifier) +{ + uint32_t i; /* Loop Counter */ + q31_t outR, outI; /* Temporary variables for output */ + const 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[4 * fftLen - 1]; + q31_t *pIn1 = &pSrc[2], *pIn2 = &pSrc[2 * fftLen - 1]; + + /* Init coefficient pointers */ + pCoefA = &pATable[modifier * 2]; + pCoefB = &pBTable[modifier * 2]; + + 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] */ + mult_32x32_keep32_R (outR, *pIn1, CoefA1); + + /* outI = pIn[2 * i] * pATable[2 * i + 1] */ + mult_32x32_keep32_R (outI, *pIn1++, CoefA2); + + /* - pSrc[2 * i + 1] * pATable[2 * i + 1] */ + multSub_32x32_keep32_R (outR, *pIn1, CoefA2); + + /* (pIn[2 * i + 1] * pATable[2 * i] */ + multAcc_32x32_keep32_R (outI, *pIn1++, CoefA1); + + /* pSrc[2 * n - 2 * i] * pBTable[2 * i] */ + multSub_32x32_keep32_R (outR, *pIn2, CoefA2); + CoefB1 = *pCoefB; + + /* pIn[2 * n - 2 * i] * pBTable[2 * i + 1] */ + multSub_32x32_keep32_R (outI, *pIn2--, CoefB1); + + /* pSrc[2 * n - 2 * i + 1] * pBTable[2 * i + 1] */ + multAcc_32x32_keep32_R (outR, *pIn2, CoefB1); + + /* pIn[2 * n - 2 * i + 1] * pBTable[2 * i] */ + multSub_32x32_keep32_R (outI, *pIn2--, CoefA2); + + /* write output */ + *pOut1++ = outR; + *pOut1++ = outI; + + /* write complex conjugate output */ + *pOut2-- = -outI; + *pOut2-- = outR; + + /* update coefficient pointer */ + pCoefB = pCoefB + (2 * modifier); + pCoefA = pCoefA + (2 * modifier - 1); + + /* Decrement loop count */ + i--; + } + + pDst[2 * fftLen] = (pSrc[0] - pSrc[1]) >> 1U; + pDst[2 * fftLen + 1] = 0; + + pDst[0] = (pSrc[0] + pSrc[1]) >> 1U; + pDst[1] = 0; +} + + +/** + @brief Core Real IFFT process + @param[in] pSrc points to input buffer + @param[in] fftLen length of FFT + @param[in] pATable points to twiddle Coef A buffer + @param[in] pBTable points to twiddle Coef B buffer + @param[out] pDst points to 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, + const q31_t * pATable, + const q31_t * pBTable, + q31_t * pDst, + uint32_t modifier) +{ + q31_t outR, outI; /* Temporary variables for output */ + const 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[2 * fftLen + 1]; + + 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] */ + mult_32x32_keep32_R (outR, *pIn1, CoefA1); + + /* - pIn[2 * i] * pATable[2 * i + 1] */ + mult_32x32_keep32_R (outI, *pIn1++, -CoefA2); + + /* pIn[2 * i + 1] * pATable[2 * i + 1] */ + multAcc_32x32_keep32_R (outR, *pIn1, CoefA2); + + /* pIn[2 * i + 1] * pATable[2 * i] */ + multAcc_32x32_keep32_R (outI, *pIn1++, CoefA1); + + /* pIn[2 * n - 2 * i] * pBTable[2 * i] */ + multAcc_32x32_keep32_R (outR, *pIn2, CoefA2); + CoefB1 = *pCoefB; + + /* pIn[2 * n - 2 * i] * pBTable[2 * i + 1] */ + multSub_32x32_keep32_R (outI, *pIn2--, CoefB1); + + /* pIn[2 * n - 2 * i + 1] * pBTable[2 * i + 1] */ + multAcc_32x32_keep32_R (outR, *pIn2, CoefB1); + + /* pIn[2 * n - 2 * i + 1] * pBTable[2 * i] */ + multAcc_32x32_keep32_R (outI, *pIn2--, CoefA2); + + /* write output */ + *pDst++ = outR; + *pDst++ = outI; + + /* update coefficient pointer */ + pCoefB = pCoefB + (modifier * 2); + pCoefA = pCoefA + (modifier * 2 - 1); + + /* Decrement loop count */ + fftLen--; + } + +} -- cgit v1.2.3