You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
252 lines
6.1 KiB
252 lines
6.1 KiB
/* ----------------------------------------------------------------------
|
|
* 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;
|
|
}
|
|
}
|
|
|
|
|