tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/TransformFunctions/arm_rfft_fast_init_f32.c

   1 /* ----------------------------------------------------------------------
   2 * Copyright (C) 2010-2013 ARM Limited. All rights reserved.
   3 *
   4 * $Date:        17. January 2013
   5 * $Revision:    V1.4.1
   6 *
   7 * Project:          CMSIS DSP Library
   8 * Title:            arm_cfft_init_f32.c
   9 *
  10 * Description:  Split Radix Decimation in Frequency CFFT Floating point processing 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 #include "arm_math.h"
  42 #include "arm_common_tables.h"
  43
  44 /**
  45  * @ingroup groupTransforms
  46  */
  47
  48 /**
  49  * @addtogroup RealFFT
  50  * @{
  51  */
  52
  53 /**
  54 * @brief  Initialization function for the floating-point real FFT.
  55 * @param[in,out] *S             points to an arm_rfft_fast_instance_f32 structure.
  56 * @param[in]     fftLen         length of the Real Sequence.
  57 * @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.
  58 *
  59 * \par Description:
  60 * \par
  61 * The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
  62 * Set(=1) ifftFlag for calculation of CIFFT otherwise  RFFT is calculated
  63 * \par
  64 * The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
  65 * Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
  66 * \par
  67 * The parameter <code>fftLen</code>     Specifies length of RFFT/CIFFT process. Supported FFT Lengths are 16, 32, 64, 128, 256, 512, 1024, 2048, 4096.
  68 * \par
  69 * This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
  70 */
  71 arm_status arm_rfft_fast_init_f32(
  72   arm_rfft_fast_instance_f32 * S,
  73   uint16_t fftLen)
  74 {
  75   arm_cfft_instance_f32 * Sint;
  76   /*  Initialise the default arm status */
  77   arm_status status = ARM_MATH_SUCCESS;
  78   /*  Initialise the FFT length */
  79   Sint = &(S->Sint);
  80   Sint->fftLen = fftLen/2;
  81   S->fftLenRFFT = fftLen;
  82   /*  Initialise the Twiddle coefficient pointer */
  83   //  S->pTwiddle = (float32_t *) twiddleCoef;
  84
  85   /*  Initializations of structure parameters depending on the FFT length */
  86   switch (Sint->fftLen)
  87   {
  88   case 4096u:
  89     /*  Initializations of structure parameters for 4096 point FFT */
  90     /*  Initialise the bit reversal table length */
  91     Sint->bitRevLength = ARMBITREVINDEXTABLE4096_TABLE_LENGTH;
  92     /*  Initialise the bit reversal table pointer */
  93     Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable4096;
  94     /*  Initialise the 1/fftLen Value */
  95     break;
  96   case 2048u:
  97     Sint->bitRevLength = ARMBITREVINDEXTABLE2048_TABLE_LENGTH;
  98     Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable2048;
  99     break;
 100   case 1024u:
 101     Sint->bitRevLength = ARMBITREVINDEXTABLE1024_TABLE_LENGTH;
 102     Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable1024;
 103     break;
 104   case 512u:
 105     Sint->bitRevLength = ARMBITREVINDEXTABLE_512_TABLE_LENGTH;
 106     Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable512;
 107     break;
 108   case 256u:
 109     Sint->bitRevLength = ARMBITREVINDEXTABLE_256_TABLE_LENGTH;
 110     Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable256;
 111     break;
 112   case 128u:
 113     Sint->bitRevLength = ARMBITREVINDEXTABLE_128_TABLE_LENGTH;
 114     Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable128;
 115     break;
 116   case 64u:
 117     Sint->bitRevLength = ARMBITREVINDEXTABLE__64_TABLE_LENGTH;
 118     Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable64;
 119     break;
 120   case 32u:
 121     Sint->bitRevLength = ARMBITREVINDEXTABLE__32_TABLE_LENGTH;
 122     Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable32;
 123     break;
 124   case 16u:
 125     Sint->bitRevLength = ARMBITREVINDEXTABLE__16_TABLE_LENGTH;
 126     Sint->pBitRevTable = (uint16_t *)armBitRevIndexTable16;
 127     break;
 128   default:
 129     /*  Reporting argument error if fftSize is not valid value */
 130     status = ARM_MATH_ARGUMENT_ERROR;
 131     break;
 132   }
 133
 134   return (status);
 135 }
 136
 137 /**
 138  * @} end of RealFFT group
 139  */