1  /* ----------------------------------------------------------------------
  2   * Project:      CMSIS DSP Library
  3   * Title:        arm_rfft_init_q31.c
  4   * Description:  RFFT & RIFFT Q31 initialisation function
  5   *
  6   * $Date:        23 April 2021
  7   * $Revision:    V1.9.0
  8   *
  9   * Target Processor: Cortex-M and Cortex-A cores
 10   * -------------------------------------------------------------------- */
 11  /*
 12   * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
 13   *
 14   * SPDX-License-Identifier: Apache-2.0
 15   *
 16   * Licensed under the Apache License, Version 2.0 (the License); you may
 17   * not use this file except in compliance with the License.
 18   * You may obtain a copy of the License at
 19   *
 20   * www.apache.org/licenses/LICENSE-2.0
 21   *
 22   * Unless required by applicable law or agreed to in writing, software
 23   * distributed under the License is distributed on an AS IS BASIS, WITHOUT
 24   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 25   * See the License for the specific language governing permissions and
 26   * limitations under the License.
 27   */
 28  
 29  #include "dsp/transform_functions.h"
 30  #include "arm_common_tables.h"
 31  #include "arm_const_structs.h"
 32  
 33  
 34  
 35  /**
 36    @addtogroup RealFFT
 37    @{
 38   */
 39  
 40  /**
 41    @brief         Initialization function for the Q31 RFFT/RIFFT.
 42    @param[in,out] S              points to an instance of the Q31 RFFT/RIFFT structure
 43    @param[in]     fftLenReal     length of the FFT
 44    @param[in]     ifftFlagR      flag that selects transform direction
 45                     - value = 0: forward transform
 46                     - value = 1: inverse transform
 47    @param[in]     bitReverseFlag flag that enables / disables bit reversal of output
 48                     - value = 0: disables bit reversal of output
 49                     - value = 1: enables bit reversal of output
 50    @return        execution status
 51                     - \ref ARM_MATH_SUCCESS        : Operation successful
 52                     - \ref ARM_MATH_ARGUMENT_ERROR : <code>fftLenReal</code> is not a supported length
 53  
 54    @par           Details
 55                     The parameter <code>fftLenReal</code> specifies length of RFFT/RIFFT Process.
 56                     Supported FFT Lengths are 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192.
 57    @par
 58                     The parameter <code>ifftFlagR</code> controls whether a forward or inverse transform is computed.
 59                     Set(=1) ifftFlagR to calculate RIFFT, otherwise RFFT is calculated.
 60    @par
 61                     The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
 62                     Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
 63    @par
 64                     This function also initializes Twiddle factor table.
 65  */
 66  
 67  arm_status arm_rfft_init_q31(
 68      arm_rfft_instance_q31 * S,
 69      uint32_t fftLenReal,
 70      uint32_t ifftFlagR,
 71      uint32_t bitReverseFlag)
 72  {
 73       /*  Initialise the default arm status */
 74      arm_status status = ARM_MATH_ARGUMENT_ERROR;
 75  
 76  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_FFT_ALLOW_TABLES)
 77  
 78  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_REALCOEF_Q31)
 79  
 80      /*  Initialise the default arm status */
 81      status = ARM_MATH_SUCCESS;
 82  
 83      /*  Initialize the Real FFT length */
 84      S->fftLenReal = (uint16_t) fftLenReal;
 85  
 86      /*  Initialize the Twiddle coefficientA pointer */
 87      S->pTwiddleAReal = (q31_t *) realCoefAQ31;
 88  
 89      /*  Initialize the Twiddle coefficientB pointer */
 90      S->pTwiddleBReal = (q31_t *) realCoefBQ31;
 91  
 92      /*  Initialize the Flag for selection of RFFT or RIFFT */
 93      S->ifftFlagR = (uint8_t) ifftFlagR;
 94  
 95      /*  Initialize the Flag for calculation Bit reversal or not */
 96      S->bitReverseFlagR = (uint8_t) bitReverseFlag;
 97  
 98      /*  Initialization of coef modifier depending on the FFT length */
 99      switch (S->fftLenReal)
100      {
101  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_4096) && defined(ARM_TABLE_BITREVIDX_FXT_4096))
102      case 8192U:
103  
104  
105          S->twidCoefRModifier = 1U;
106  
107          #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
108             status=arm_cfft_init_q31(&(S->cfftInst),4096);
109             if (status != ARM_MATH_SUCCESS)
110             {
111                 return(status);
112             }
113          #else
114             S->pCfft = &arm_cfft_sR_q31_len4096;
115          #endif
116          break;
117  #endif
118  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_2048) && defined(ARM_TABLE_BITREVIDX_FXT_2048))
119      case 4096U:
120          S->twidCoefRModifier = 2U;
121  
122          #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
123             status=arm_cfft_init_q31(&(S->cfftInst),2048);
124             if (status != ARM_MATH_SUCCESS)
125             {
126                 return(status);
127             }
128          #else
129             S->pCfft = &arm_cfft_sR_q31_len2048;
130          #endif
131          break;
132  #endif
133  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_1024) && defined(ARM_TABLE_BITREVIDX_FXT_1024))
134      case 2048U:
135          S->twidCoefRModifier = 4U;
136  
137          #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
138             status=arm_cfft_init_q31(&(S->cfftInst),1024);
139             if (status != ARM_MATH_SUCCESS)
140             {
141                 return(status);
142             }
143          #else
144            S->pCfft = &arm_cfft_sR_q31_len1024;
145          #endif
146          break;
147  #endif
148  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_512) && defined(ARM_TABLE_BITREVIDX_FXT_512))
149      case 1024U:
150          S->twidCoefRModifier = 8U;
151          #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
152             status=arm_cfft_init_q31(&(S->cfftInst),512);
153             if (status != ARM_MATH_SUCCESS)
154             {
155                 return(status);
156             }
157          #else
158             S->pCfft = &arm_cfft_sR_q31_len512;
159          #endif
160          break;
161  #endif
162  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_256) && defined(ARM_TABLE_BITREVIDX_FXT_256))
163      case 512U:
164          S->twidCoefRModifier = 16U;
165          #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
166             status=arm_cfft_init_q31(&(S->cfftInst),256);
167             if (status != ARM_MATH_SUCCESS)
168             {
169                 return(status);
170             }
171          #else
172             S->pCfft = &arm_cfft_sR_q31_len256;
173          #endif
174          break;
175  #endif 
176  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_128) && defined(ARM_TABLE_BITREVIDX_FXT_128))
177      case 256U:
178          S->twidCoefRModifier = 32U;
179          #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
180             status=arm_cfft_init_q31(&(S->cfftInst),128);
181             if (status != ARM_MATH_SUCCESS)
182             {
183                 return(status);
184             }
185          #else
186             S->pCfft = &arm_cfft_sR_q31_len128;
187          #endif
188          break;
189  #endif 
190  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_64) && defined(ARM_TABLE_BITREVIDX_FXT_64))
191      case 128U:
192          S->twidCoefRModifier = 64U;
193          #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
194             status=arm_cfft_init_q31(&(S->cfftInst),64);
195             if (status != ARM_MATH_SUCCESS)
196             {
197                 return(status);
198             }
199          #else
200             S->pCfft = &arm_cfft_sR_q31_len64;
201          #endif
202          break;
203  #endif
204  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_32) && defined(ARM_TABLE_BITREVIDX_FXT_32))
205      case 64U:
206          S->twidCoefRModifier = 128U;
207          #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
208             status=arm_cfft_init_q31(&(S->cfftInst),32);
209             if (status != ARM_MATH_SUCCESS)
210             {
211                 return(status);
212             }
213          #else
214             S->pCfft = &arm_cfft_sR_q31_len32;
215          #endif
216          break;
217  #endif 
218  #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_16) && defined(ARM_TABLE_BITREVIDX_FXT_16))
219      case 32U:
220          S->twidCoefRModifier = 256U;
221          #if defined(ARM_MATH_MVEI) && !defined(ARM_MATH_AUTOVECTORIZE)
222             status=arm_cfft_init_q31(&(S->cfftInst),16);
223             if (status != ARM_MATH_SUCCESS)
224             {
225                 return(status);
226             }
227          #else
228             S->pCfft = &arm_cfft_sR_q31_len16;
229          #endif
230          break;
231  #endif
232      default:
233          /*  Reporting argument error if rfftSize is not valid value */
234          status = ARM_MATH_ARGUMENT_ERROR;
235          break;
236      }
237  
238  #endif
239  #endif
240      /* return the status of RFFT Init function */
241      return (status);
242  }
243  
244  /**
245    @} end of RealFFT group
246   */