The CMSIS DSP 5 library
Dependents: Nucleo-Heart-Rate ejercicioVrms2 PROYECTOFINAL ejercicioVrms ... more
functions/TransformFunctions/arm_cfft_q31.c
- Committer:
- xorjoep
- Date:
- 2018-06-21
- Revision:
- 3:4098b9d3d571
- Parent:
- 1:24714b45cd1b
File content as of revision 3:4098b9d3d571:
/* ---------------------------------------------------------------------- * Project: CMSIS DSP Library * Title: arm_cfft_q31.c * Description: Combined Radix Decimation in Frequency CFFT fixed point processing function * * $Date: 27. January 2017 * $Revision: V.1.5.1 * * Target Processor: Cortex-M cores * -------------------------------------------------------------------- */ /* * Copyright (C) 2010-2017 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" extern void arm_radix4_butterfly_q31( q31_t * pSrc, uint32_t fftLen, q31_t * pCoef, uint32_t twidCoefModifier); extern void arm_radix4_butterfly_inverse_q31( q31_t * pSrc, uint32_t fftLen, q31_t * pCoef, uint32_t twidCoefModifier); extern void arm_bitreversal_32( uint32_t * pSrc, const uint16_t bitRevLen, const uint16_t * pBitRevTable); void arm_cfft_radix4by2_q31( q31_t * pSrc, uint32_t fftLen, const q31_t * pCoef); void arm_cfft_radix4by2_inverse_q31( q31_t * pSrc, uint32_t fftLen, const q31_t * pCoef); /** * @ingroup groupTransforms */ /** * @addtogroup ComplexFFT * @{ */ /** * @details * @brief Processing function for the fixed-point complex FFT in Q31 format. * @param[in] *S points to an instance of the fixed-point CFFT structure. * @param[in, out] *p1 points to the complex data buffer of size <code>2*fftLen</code>. Processing occurs in-place. * @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. * @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. * @return none. */ void arm_cfft_q31( const arm_cfft_instance_q31 * S, q31_t * p1, uint8_t ifftFlag, uint8_t bitReverseFlag) { uint32_t L = S->fftLen; if (ifftFlag == 1U) { switch (L) { case 16: case 64: case 256: case 1024: case 4096: arm_radix4_butterfly_inverse_q31 ( p1, L, (q31_t*)S->pTwiddle, 1 ); break; case 32: case 128: case 512: case 2048: arm_cfft_radix4by2_inverse_q31 ( p1, L, S->pTwiddle ); break; } } else { switch (L) { case 16: case 64: case 256: case 1024: case 4096: arm_radix4_butterfly_q31 ( p1, L, (q31_t*)S->pTwiddle, 1 ); break; case 32: case 128: case 512: case 2048: arm_cfft_radix4by2_q31 ( p1, L, S->pTwiddle ); break; } } if ( bitReverseFlag ) arm_bitreversal_32((uint32_t*)p1,S->bitRevLength,S->pBitRevTable); } /** * @} end of ComplexFFT group */ void arm_cfft_radix4by2_q31( q31_t * pSrc, uint32_t fftLen, const q31_t * pCoef) { uint32_t i, l; uint32_t n2, ia; q31_t xt, yt, cosVal, sinVal; q31_t p0, p1; n2 = fftLen >> 1; ia = 0; for (i = 0; i < n2; i++) { cosVal = pCoef[2*ia]; sinVal = pCoef[2*ia + 1]; ia++; l = i + n2; xt = (pSrc[2 * i] >> 2) - (pSrc[2 * l] >> 2); pSrc[2 * i] = (pSrc[2 * i] >> 2) + (pSrc[2 * l] >> 2); yt = (pSrc[2 * i + 1] >> 2) - (pSrc[2 * l + 1] >> 2); pSrc[2 * i + 1] = (pSrc[2 * l + 1] >> 2) + (pSrc[2 * i + 1] >> 2); mult_32x32_keep32_R(p0, xt, cosVal); mult_32x32_keep32_R(p1, yt, cosVal); multAcc_32x32_keep32_R(p0, yt, sinVal); multSub_32x32_keep32_R(p1, xt, sinVal); pSrc[2U * l] = p0 << 1; pSrc[2U * l + 1U] = p1 << 1; } // first col arm_radix4_butterfly_q31( pSrc, n2, (q31_t*)pCoef, 2U); // second col arm_radix4_butterfly_q31( pSrc + fftLen, n2, (q31_t*)pCoef, 2U); for (i = 0; i < fftLen >> 1; i++) { p0 = pSrc[4*i+0]; p1 = pSrc[4*i+1]; xt = pSrc[4*i+2]; yt = pSrc[4*i+3]; p0 <<= 1; p1 <<= 1; xt <<= 1; yt <<= 1; pSrc[4*i+0] = p0; pSrc[4*i+1] = p1; pSrc[4*i+2] = xt; pSrc[4*i+3] = yt; } } void arm_cfft_radix4by2_inverse_q31( q31_t * pSrc, uint32_t fftLen, const q31_t * pCoef) { uint32_t i, l; uint32_t n2, ia; q31_t xt, yt, cosVal, sinVal; q31_t p0, p1; n2 = fftLen >> 1; ia = 0; for (i = 0; i < n2; i++) { cosVal = pCoef[2*ia]; sinVal = pCoef[2*ia + 1]; ia++; l = i + n2; xt = (pSrc[2 * i] >> 2) - (pSrc[2 * l] >> 2); pSrc[2 * i] = (pSrc[2 * i] >> 2) + (pSrc[2 * l] >> 2); yt = (pSrc[2 * i + 1] >> 2) - (pSrc[2 * l + 1] >> 2); pSrc[2 * i + 1] = (pSrc[2 * l + 1] >> 2) + (pSrc[2 * i + 1] >> 2); mult_32x32_keep32_R(p0, xt, cosVal); mult_32x32_keep32_R(p1, yt, cosVal); multSub_32x32_keep32_R(p0, yt, sinVal); multAcc_32x32_keep32_R(p1, xt, sinVal); pSrc[2U * l] = p0 << 1; pSrc[2U * l + 1U] = p1 << 1; } // first col arm_radix4_butterfly_inverse_q31( pSrc, n2, (q31_t*)pCoef, 2U); // second col arm_radix4_butterfly_inverse_q31( pSrc + fftLen, n2, (q31_t*)pCoef, 2U); for (i = 0; i < fftLen >> 1; i++) { p0 = pSrc[4*i+0]; p1 = pSrc[4*i+1]; xt = pSrc[4*i+2]; yt = pSrc[4*i+3]; p0 <<= 1; p1 <<= 1; xt <<= 1; yt <<= 1; pSrc[4*i+0] = p0; pSrc[4*i+1] = p1; pSrc[4*i+2] = xt; pSrc[4*i+3] = yt; } }