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| bfc108 | 1 | /* ---------------------------------------------------------------------- |
| Q | 2 | * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
| 3 | * | |
| 4 | * $Date: 19. March 2015 | |
| 5 | * $Revision: V.1.4.5 | |
| 6 | * | |
| 7 | * Project: CMSIS DSP Library | |
| 8 | * Title: arm_cfft_radix2_init_q31.c | |
| 9 | * | |
| 10 | * Description: Radix-2 Decimation in Frequency Fixed-point CFFT & CIFFT Initialization function | |
| 11 | * | |
| 12 | * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 | |
| 13 | * | |
| 14 | * Redistribution and use in source and binary forms, with or without | |
| 15 | * modification, are permitted provided that the following conditions | |
| 16 | * are met: | |
| 17 | * - Redistributions of source code must retain the above copyright | |
| 18 | * notice, this list of conditions and the following disclaimer. | |
| 19 | * - Redistributions in binary form must reproduce the above copyright | |
| 20 | * notice, this list of conditions and the following disclaimer in | |
| 21 | * the documentation and/or other materials provided with the | |
| 22 | * distribution. | |
| 23 | * - Neither the name of ARM LIMITED nor the names of its contributors | |
| 24 | * may be used to endorse or promote products derived from this | |
| 25 | * software without specific prior written permission. | |
| 26 | * | |
| 27 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS | |
| 28 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT | |
| 29 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS | |
| 30 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE | |
| 31 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, | |
| 32 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, | |
| 33 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
| 34 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER | |
| 35 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 36 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN | |
| 37 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| 38 | * POSSIBILITY OF SUCH DAMAGE. | |
| 39 | * -------------------------------------------------------------------- */ | |
| 40 | ||
| 41 | ||
| 42 | #include "arm_math.h" | |
| 43 | #include "arm_common_tables.h" | |
| 44 | ||
| 45 | /** | |
| 46 | * @ingroup groupTransforms | |
| 47 | */ | |
| 48 | ||
| 49 | /** | |
| 50 | * @addtogroup ComplexFFT | |
| 51 | * @{ | |
| 52 | */ | |
| 53 | ||
| 54 | ||
| 55 | /** | |
| 56 | * | |
| 57 | * @brief Initialization function for the Q31 CFFT/CIFFT. | |
| 58 | * @deprecated Do not use this function. It has been superseded by \ref arm_cfft_q31 and will be removed | |
| 59 | * @param[in,out] *S points to an instance of the Q31 CFFT/CIFFT structure. | |
| 60 | * @param[in] fftLen length of the FFT. | |
| 61 | * @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. | |
| 62 | * @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. | |
| 63 | * @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. | |
| 64 | * | |
| 65 | * \par Description: | |
| 66 | * \par | |
| 67 | * The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed. | |
| 68 | * Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated | |
| 69 | * \par | |
| 70 | * The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order. | |
| 71 | * Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order. | |
| 72 | * \par | |
| 73 | * The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. | |
| 74 | * \par | |
| 75 | * This Function also initializes Twiddle factor table pointer and Bit reversal table pointer. | |
| 76 | */ | |
| 77 | ||
| 78 | arm_status arm_cfft_radix2_init_q31( | |
| 79 | arm_cfft_radix2_instance_q31 * S, | |
| 80 | uint16_t fftLen, | |
| 81 | uint8_t ifftFlag, | |
| 82 | uint8_t bitReverseFlag) | |
| 83 | { | |
| 84 | /* Initialise the default arm status */ | |
| 85 | arm_status status = ARM_MATH_SUCCESS; | |
| 86 | ||
| 87 | /* Initialise the FFT length */ | |
| 88 | S->fftLen = fftLen; | |
| 89 | ||
| 90 | /* Initialise the Twiddle coefficient pointer */ | |
| 91 | S->pTwiddle = (q31_t *) twiddleCoef_4096_q31; | |
| 92 | /* Initialise the Flag for selection of CFFT or CIFFT */ | |
| 93 | S->ifftFlag = ifftFlag; | |
| 94 | /* Initialise the Flag for calculation Bit reversal or not */ | |
| 95 | S->bitReverseFlag = bitReverseFlag; | |
| 96 | ||
| 97 | /* Initializations of Instance structure depending on the FFT length */ | |
| 98 | switch (S->fftLen) | |
| 99 | { | |
| 100 | /* Initializations of structure parameters for 4096 point FFT */ | |
| 101 | case 4096u: | |
| 102 | /* Initialise the twiddle coef modifier value */ | |
| 103 | S->twidCoefModifier = 1u; | |
| 104 | /* Initialise the bit reversal table modifier */ | |
| 105 | S->bitRevFactor = 1u; | |
| 106 | /* Initialise the bit reversal table pointer */ | |
| 107 | S->pBitRevTable = (uint16_t *) armBitRevTable; | |
| 108 | break; | |
| 109 | ||
| 110 | /* Initializations of structure parameters for 2048 point FFT */ | |
| 111 | case 2048u: | |
| 112 | /* Initialise the twiddle coef modifier value */ | |
| 113 | S->twidCoefModifier = 2u; | |
| 114 | /* Initialise the bit reversal table modifier */ | |
| 115 | S->bitRevFactor = 2u; | |
| 116 | /* Initialise the bit reversal table pointer */ | |
| 117 | S->pBitRevTable = (uint16_t *) & armBitRevTable[1]; | |
| 118 | break; | |
| 119 | ||
| 120 | /* Initializations of structure parameters for 1024 point FFT */ | |
| 121 | case 1024u: | |
| 122 | /* Initialise the twiddle coef modifier value */ | |
| 123 | S->twidCoefModifier = 4u; | |
| 124 | /* Initialise the bit reversal table modifier */ | |
| 125 | S->bitRevFactor = 4u; | |
| 126 | /* Initialise the bit reversal table pointer */ | |
| 127 | S->pBitRevTable = (uint16_t *) & armBitRevTable[3]; | |
| 128 | break; | |
| 129 | ||
| 130 | /* Initializations of structure parameters for 512 point FFT */ | |
| 131 | case 512u: | |
| 132 | /* Initialise the twiddle coef modifier value */ | |
| 133 | S->twidCoefModifier = 8u; | |
| 134 | /* Initialise the bit reversal table modifier */ | |
| 135 | S->bitRevFactor = 8u; | |
| 136 | /* Initialise the bit reversal table pointer */ | |
| 137 | S->pBitRevTable = (uint16_t *) & armBitRevTable[7]; | |
| 138 | break; | |
| 139 | ||
| 140 | case 256u: | |
| 141 | /* Initializations of structure parameters for 256 point FFT */ | |
| 142 | S->twidCoefModifier = 16u; | |
| 143 | S->bitRevFactor = 16u; | |
| 144 | S->pBitRevTable = (uint16_t *) & armBitRevTable[15]; | |
| 145 | break; | |
| 146 | ||
| 147 | case 128u: | |
| 148 | /* Initializations of structure parameters for 128 point FFT */ | |
| 149 | S->twidCoefModifier = 32u; | |
| 150 | S->bitRevFactor = 32u; | |
| 151 | S->pBitRevTable = (uint16_t *) & armBitRevTable[31]; | |
| 152 | break; | |
| 153 | ||
| 154 | case 64u: | |
| 155 | /* Initializations of structure parameters for 64 point FFT */ | |
| 156 | S->twidCoefModifier = 64u; | |
| 157 | S->bitRevFactor = 64u; | |
| 158 | S->pBitRevTable = (uint16_t *) & armBitRevTable[63]; | |
| 159 | break; | |
| 160 | ||
| 161 | case 32u: | |
| 162 | /* Initializations of structure parameters for 32 point FFT */ | |
| 163 | S->twidCoefModifier = 128u; | |
| 164 | S->bitRevFactor = 128u; | |
| 165 | S->pBitRevTable = (uint16_t *) & armBitRevTable[127]; | |
| 166 | break; | |
| 167 | ||
| 168 | case 16u: | |
| 169 | /* Initializations of structure parameters for 16 point FFT */ | |
| 170 | S->twidCoefModifier = 256u; | |
| 171 | S->bitRevFactor = 256u; | |
| 172 | S->pBitRevTable = (uint16_t *) & armBitRevTable[255]; | |
| 173 | break; | |
| 174 | ||
| 175 | ||
| 176 | default: | |
| 177 | /* Reporting argument error if fftSize is not valid value */ | |
| 178 | status = ARM_MATH_ARGUMENT_ERROR; | |
| 179 | break; | |
| 180 | } | |
| 181 | ||
| 182 | return (status); | |
| 183 | } | |
| 184 | ||
| 185 | /** | |
| 186 | * @} end of ComplexFFT group | |
| 187 | */ | |
