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| 2 | mjames | 1 | /* ---------------------------------------------------------------------- |
| 2 | * Copyright (C) 2010-2014 ARM Limited. All rights reserved. |
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| 3 | * |
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| 4 | * $Date: 19. March 2015 |
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| 5 | * $Revision: V.1.4.5 |
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| 6 | * |
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| 7 | * Project: CMSIS DSP Library |
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| 8 | * Title: arm_cfft_radix4_init_q31.c |
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| 9 | * |
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| 10 | * Description: Radix-4 Decimation in Frequency Q31 FFT & IFFT initialization function |
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| 11 | * |
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| 12 | * Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 |
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| 13 | * |
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| 14 | * Redistribution and use in source and binary forms, with or without |
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| 15 | * modification, are permitted provided that the following conditions |
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| 16 | * are met: |
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| 17 | * - Redistributions of source code must retain the above copyright |
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| 18 | * notice, this list of conditions and the following disclaimer. |
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| 19 | * - Redistributions in binary form must reproduce the above copyright |
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| 20 | * notice, this list of conditions and the following disclaimer in |
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| 21 | * the documentation and/or other materials provided with the |
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| 22 | * distribution. |
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| 23 | * - Neither the name of ARM LIMITED nor the names of its contributors |
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| 24 | * may be used to endorse or promote products derived from this |
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| 25 | * software without specific prior written permission. |
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| 26 | * |
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| 27 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
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| 28 | * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
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| 29 | * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
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| 30 | * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
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| 31 | * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, |
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| 32 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, |
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| 33 | * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
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| 34 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
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| 35 | * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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| 36 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN |
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| 37 | * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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| 38 | * POSSIBILITY OF SUCH DAMAGE. |
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| 39 | * -------------------------------------------------------------------- */ |
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| 40 | |||
| 41 | #include "arm_math.h" |
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| 42 | #include "arm_common_tables.h" |
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| 43 | |||
| 44 | /** |
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| 45 | * @ingroup groupTransforms |
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| 46 | */ |
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| 47 | |||
| 48 | /** |
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| 49 | * @addtogroup ComplexFFT |
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| 50 | * @{ |
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| 51 | */ |
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| 52 | |||
| 53 | /** |
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| 54 | * |
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| 55 | * @brief Initialization function for the Q31 CFFT/CIFFT. |
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| 56 | * @deprecated Do not use this function. It has been superseded by \ref arm_cfft_q31 and will be removed |
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| 57 | * @param[in,out] *S points to an instance of the Q31 CFFT/CIFFT structure. |
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| 58 | * @param[in] fftLen length of the FFT. |
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| 59 | * @param[in] ifftFlag flag that selects forward (ifftFlag=0) or inverse (ifftFlag=1) transform. |
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| 60 | * @param[in] bitReverseFlag flag that enables (bitReverseFlag=1) or disables (bitReverseFlag=0) bit reversal of output. |
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| 61 | * @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. |
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| 62 | * |
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| 63 | * \par Description: |
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| 64 | * \par |
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| 65 | * The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed. |
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| 66 | * Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated |
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| 67 | * \par |
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| 68 | * The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order. |
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| 69 | * Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order. |
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| 70 | * \par |
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| 71 | * The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024. |
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| 72 | * \par |
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| 73 | * This Function also initializes Twiddle factor table pointer and Bit reversal table pointer. |
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| 74 | */ |
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| 75 | |||
| 76 | arm_status arm_cfft_radix4_init_q31( |
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| 77 | arm_cfft_radix4_instance_q31 * S, |
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| 78 | uint16_t fftLen, |
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| 79 | uint8_t ifftFlag, |
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| 80 | uint8_t bitReverseFlag) |
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| 81 | { |
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| 82 | /* Initialise the default arm status */ |
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| 83 | arm_status status = ARM_MATH_SUCCESS; |
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| 84 | /* Initialise the FFT length */ |
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| 85 | S->fftLen = fftLen; |
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| 86 | /* Initialise the Twiddle coefficient pointer */ |
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| 87 | S->pTwiddle = (q31_t *) twiddleCoef_4096_q31; |
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| 88 | /* Initialise the Flag for selection of CFFT or CIFFT */ |
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| 89 | S->ifftFlag = ifftFlag; |
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| 90 | /* Initialise the Flag for calculation Bit reversal or not */ |
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| 91 | S->bitReverseFlag = bitReverseFlag; |
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| 92 | |||
| 93 | /* Initializations of Instance structure depending on the FFT length */ |
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| 94 | switch (S->fftLen) |
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| 95 | { |
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| 96 | /* Initializations of structure parameters for 4096 point FFT */ |
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| 97 | case 4096u: |
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| 98 | /* Initialise the twiddle coef modifier value */ |
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| 99 | S->twidCoefModifier = 1u; |
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| 100 | /* Initialise the bit reversal table modifier */ |
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| 101 | S->bitRevFactor = 1u; |
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| 102 | /* Initialise the bit reversal table pointer */ |
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| 103 | S->pBitRevTable = (uint16_t *) armBitRevTable; |
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| 104 | break; |
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| 105 | |||
| 106 | /* Initializations of structure parameters for 1024 point FFT */ |
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| 107 | case 1024u: |
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| 108 | /* Initialise the twiddle coef modifier value */ |
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| 109 | S->twidCoefModifier = 4u; |
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| 110 | /* Initialise the bit reversal table modifier */ |
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| 111 | S->bitRevFactor = 4u; |
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| 112 | /* Initialise the bit reversal table pointer */ |
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| 113 | S->pBitRevTable = (uint16_t *) & armBitRevTable[3]; |
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| 114 | break; |
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| 115 | |||
| 116 | case 256u: |
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| 117 | /* Initializations of structure parameters for 256 point FFT */ |
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| 118 | S->twidCoefModifier = 16u; |
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| 119 | S->bitRevFactor = 16u; |
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| 120 | S->pBitRevTable = (uint16_t *) & armBitRevTable[15]; |
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| 121 | break; |
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| 122 | |||
| 123 | case 64u: |
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| 124 | /* Initializations of structure parameters for 64 point FFT */ |
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| 125 | S->twidCoefModifier = 64u; |
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| 126 | S->bitRevFactor = 64u; |
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| 127 | S->pBitRevTable = (uint16_t *) & armBitRevTable[63]; |
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| 128 | break; |
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| 129 | |||
| 130 | case 16u: |
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| 131 | /* Initializations of structure parameters for 16 point FFT */ |
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| 132 | S->twidCoefModifier = 256u; |
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| 133 | S->bitRevFactor = 256u; |
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| 134 | S->pBitRevTable = (uint16_t *) & armBitRevTable[255]; |
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| 135 | break; |
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| 136 | |||
| 137 | default: |
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| 138 | /* Reporting argument error if fftSize is not valid value */ |
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| 139 | status = ARM_MATH_ARGUMENT_ERROR; |
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| 140 | break; |
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| 141 | } |
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| 142 | |||
| 143 | return (status); |
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| 144 | } |
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| 145 | |||
| 146 | /** |
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| 147 | * @} end of ComplexFFT group |
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| 148 | */ |