+++ /dev/null
-/* ----------------------------------------------------------------------
-* Copyright (C) 2010-2013 ARM Limited. All rights reserved.
-*
-* $Date: 17. January 2013
-* $Revision: V1.4.1
-*
-* Project: CMSIS DSP Library
-* Title: arm_cfft_radix4_init_q15.c
-*
-* Description: Radix-4 Decimation in Frequency Q15 FFT & IFFT initialization 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"
-#include "arm_common_tables.h"
-
-/**
- * @ingroup groupTransforms
- */
-
-
-/**
- * @addtogroup ComplexFFT
- * @{
- */
-
-
-/**
-* @brief Initialization function for the Q15 CFFT/CIFFT.
-* @param[in,out] *S points to an instance of the Q15 CFFT/CIFFT structure.
-* @param[in] fftLen length of the FFT.
-* @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 The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if <code>fftLen</code> is not a supported value.
-*
-* \par Description:
-* \par
-* The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
-* Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
-* \par
-* The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
-* Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
-* \par
-* The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
-* \par
-* This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
-*/
-
-arm_status arm_cfft_radix4_init_q15(
- arm_cfft_radix4_instance_q15 * S,
- uint16_t fftLen,
- uint8_t ifftFlag,
- uint8_t bitReverseFlag)
-{
- /* Initialise the default arm status */
- arm_status status = ARM_MATH_SUCCESS;
- /* Initialise the FFT length */
- S->fftLen = fftLen;
- /* Initialise the Twiddle coefficient pointer */
- S->pTwiddle = (q15_t *) twiddleCoefQ15;
- /* Initialise the Flag for selection of CFFT or CIFFT */
- S->ifftFlag = ifftFlag;
- /* Initialise the Flag for calculation Bit reversal or not */
- S->bitReverseFlag = bitReverseFlag;
-
- /* Initializations of structure parameters depending on the FFT length */
- switch (S->fftLen)
- {
- case 4096u:
- /* Initializations of structure parameters for 4096 point FFT */
-
- /* Initialise the twiddle coef modifier value */
- S->twidCoefModifier = 1u;
- /* Initialise the bit reversal table modifier */
- S->bitRevFactor = 1u;
- /* Initialise the bit reversal table pointer */
- S->pBitRevTable = (uint16_t *) armBitRevTable;
-
- break;
-
- case 1024u:
- /* Initializations of structure parameters for 1024 point FFT */
- S->twidCoefModifier = 4u;
- S->bitRevFactor = 4u;
- S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
-
- break;
-
- case 256u:
- /* Initializations of structure parameters for 256 point FFT */
- S->twidCoefModifier = 16u;
- S->bitRevFactor = 16u;
- S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
-
- break;
-
- case 64u:
- /* Initializations of structure parameters for 64 point FFT */
- S->twidCoefModifier = 64u;
- S->bitRevFactor = 64u;
- S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
-
- break;
-
- case 16u:
- /* Initializations of structure parameters for 16 point FFT */
- S->twidCoefModifier = 256u;
- S->bitRevFactor = 256u;
- S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
-
- break;
-
- default:
- /* Reporting argument error if fftSize is not valid value */
- status = ARM_MATH_ARGUMENT_ERROR;
- break;
- }
-
- return (status);
-}
-
-/**
- * @} end of ComplexFFT group
- */
projects / qmk_firmware.git / blobdiff