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- /* ----------------------------------------------------------------------
- * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
- *
- * $Date: 17. January 2013
- * $Revision: V1.4.1
- *
- * Project: CMSIS DSP Library
- * Title: arm_cfft_init_f32.c
- *
- * Description: Split Radix Decimation in Frequency CFFT Floating point processing 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 RealFFT
- * @{
- */
-
- /**
- * @brief Initialization function for the floating-point real FFT.
- * @param[in,out] *S points to an arm_rfft_fast_instance_f32 structure.
- * @param[in] fftLen length of the Real Sequence.
- * @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 RFFT 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 RFFT/CIFFT process. Supported FFT Lengths are 16, 32, 64, 128, 256, 512, 1024, 2048, 4096.
- * \par
- * This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
- */
- arm_status arm_rfft_fast_init_f32(
- arm_rfft_fast_instance_f32 * S,
- uint16_t fftLen)
- {
- arm_cfft_instance_f32 * Sint;
- /* Initialise the default arm status */
- arm_status status = ARM_MATH_SUCCESS;
- /* Initialise the FFT length */
- Sint = &(S->Sint);
- Sint->fftLen = fftLen/2;
- S->fftLenRFFT = fftLen;
- /* Initialise the Twiddle coefficient pointer */
- // S->pTwiddle = (float32_t *) twiddleCoef;
-
- /* Initializations of structure parameters depending on the FFT length */
- switch (Sint->fftLen)
- {
- case 4096u:
- /* Initializations of structure parameters for 4096 point FFT */
- /* Initialise the bit reversal table length */
- Sint->bitRevLength = ARMBITREVINDEXTABLE4096_TABLE_LENGTH;
- /* Initialise the bit reversal table pointer */
- Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable4096;
- /* Initialise the 1/fftLen Value */
- break;
- case 2048u:
- Sint->bitRevLength = ARMBITREVINDEXTABLE2048_TABLE_LENGTH;
- Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable2048;
- break;
- case 1024u:
- Sint->bitRevLength = ARMBITREVINDEXTABLE1024_TABLE_LENGTH;
- Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable1024;
- break;
- case 512u:
- Sint->bitRevLength = ARMBITREVINDEXTABLE_512_TABLE_LENGTH;
- Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable512;
- break;
- case 256u:
- Sint->bitRevLength = ARMBITREVINDEXTABLE_256_TABLE_LENGTH;
- Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable256;
- break;
- case 128u:
- Sint->bitRevLength = ARMBITREVINDEXTABLE_128_TABLE_LENGTH;
- Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable128;
- break;
- case 64u:
- Sint->bitRevLength = ARMBITREVINDEXTABLE__64_TABLE_LENGTH;
- Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable64;
- break;
- case 32u:
- Sint->bitRevLength = ARMBITREVINDEXTABLE__32_TABLE_LENGTH;
- Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable32;
- break;
- case 16u:
- Sint->bitRevLength = ARMBITREVINDEXTABLE__16_TABLE_LENGTH;
- Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable16;
- break;
- default:
- /* Reporting argument error if fftSize is not valid value */
- status = ARM_MATH_ARGUMENT_ERROR;
- break;
- }
-
- return (status);
- }
-
- /**
- * @} end of RealFFT group
- */
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