1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_rfft_init_q31.c
4 * Description: RFFT & RIFFT Q31 initialisation function
5 *
6 * $Date: 18. March 2019
7 * $Revision: V1.6.0
8 *
9 * Target Processor: Cortex-M cores
10 * -------------------------------------------------------------------- */
11 /*
12 * Copyright (C) 2010-2019 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 "arm_math.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
arm_rfft_init_q31(arm_rfft_instance_q31 * S,uint32_t fftLenReal,uint32_t ifftFlagR,uint32_t bitReverseFlag)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_SUCCESS;
75
76 /* Initialize the Real FFT length */
77 S->fftLenReal = (uint16_t) fftLenReal;
78
79 /* Initialize the Twiddle coefficientA pointer */
80 S->pTwiddleAReal = (q31_t *) realCoefAQ31;
81
82 /* Initialize the Twiddle coefficientB pointer */
83 S->pTwiddleBReal = (q31_t *) realCoefBQ31;
84
85 /* Initialize the Flag for selection of RFFT or RIFFT */
86 S->ifftFlagR = (uint8_t) ifftFlagR;
87
88 /* Initialize the Flag for calculation Bit reversal or not */
89 S->bitReverseFlagR = (uint8_t) bitReverseFlag;
90
91 /* Initialization of coef modifier depending on the FFT length */
92 switch (S->fftLenReal)
93 {
94 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_4096) && defined(ARM_TABLE_BITREVIDX_FXT_4096))
95 case 8192U:
96
97
98 S->twidCoefRModifier = 1U;
99
100 #if defined(ARM_MATH_MVEI)
101 status=arm_cfft_init_q31(&(S->cfftInst),4096);
102 if (status != ARM_MATH_SUCCESS)
103 {
104 return(status);
105 }
106 #else
107 S->pCfft = &arm_cfft_sR_q31_len4096;
108 #endif
109 break;
110 #endif
111 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_2048) && defined(ARM_TABLE_BITREVIDX_FXT_2048))
112 case 4096U:
113 S->twidCoefRModifier = 2U;
114
115 #if defined(ARM_MATH_MVEI)
116 status=arm_cfft_init_q31(&(S->cfftInst),2048);
117 if (status != ARM_MATH_SUCCESS)
118 {
119 return(status);
120 }
121 #else
122 S->pCfft = &arm_cfft_sR_q31_len2048;
123 #endif
124 break;
125 #endif
126 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_1024) && defined(ARM_TABLE_BITREVIDX_FXT_1024))
127 case 2048U:
128 S->twidCoefRModifier = 4U;
129
130 #if defined(ARM_MATH_MVEI)
131 status=arm_cfft_init_q31(&(S->cfftInst),1024);
132 if (status != ARM_MATH_SUCCESS)
133 {
134 return(status);
135 }
136 #else
137 S->pCfft = &arm_cfft_sR_q31_len1024;
138 #endif
139 break;
140 #endif
141 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_512) && defined(ARM_TABLE_BITREVIDX_FXT_512))
142 case 1024U:
143 S->twidCoefRModifier = 8U;
144 #if defined(ARM_MATH_MVEI)
145 status=arm_cfft_init_q31(&(S->cfftInst),512);
146 if (status != ARM_MATH_SUCCESS)
147 {
148 return(status);
149 }
150 #else
151 S->pCfft = &arm_cfft_sR_q31_len512;
152 #endif
153 break;
154 #endif
155 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_256) && defined(ARM_TABLE_BITREVIDX_FXT_256))
156 case 512U:
157 S->twidCoefRModifier = 16U;
158 #if defined(ARM_MATH_MVEI)
159 status=arm_cfft_init_q31(&(S->cfftInst),256);
160 if (status != ARM_MATH_SUCCESS)
161 {
162 return(status);
163 }
164 #else
165 S->pCfft = &arm_cfft_sR_q31_len256;
166 #endif
167 break;
168 #endif
169 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_128) && defined(ARM_TABLE_BITREVIDX_FXT_128))
170 case 256U:
171 S->twidCoefRModifier = 32U;
172 #if defined(ARM_MATH_MVEI)
173 status=arm_cfft_init_q31(&(S->cfftInst),128);
174 if (status != ARM_MATH_SUCCESS)
175 {
176 return(status);
177 }
178 #else
179 S->pCfft = &arm_cfft_sR_q31_len128;
180 #endif
181 break;
182 #endif
183 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_64) && defined(ARM_TABLE_BITREVIDX_FXT_64))
184 case 128U:
185 S->twidCoefRModifier = 64U;
186 #if defined(ARM_MATH_MVEI)
187 status=arm_cfft_init_q31(&(S->cfftInst),64);
188 if (status != ARM_MATH_SUCCESS)
189 {
190 return(status);
191 }
192 #else
193 S->pCfft = &arm_cfft_sR_q31_len64;
194 #endif
195 break;
196 #endif
197 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_32) && defined(ARM_TABLE_BITREVIDX_FXT_32))
198 case 64U:
199 S->twidCoefRModifier = 128U;
200 #if defined(ARM_MATH_MVEI)
201 status=arm_cfft_init_q31(&(S->cfftInst),32);
202 if (status != ARM_MATH_SUCCESS)
203 {
204 return(status);
205 }
206 #else
207 S->pCfft = &arm_cfft_sR_q31_len32;
208 #endif
209 break;
210 #endif
211 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || (defined(ARM_TABLE_TWIDDLECOEF_Q31_16) && defined(ARM_TABLE_BITREVIDX_FXT_16))
212 case 32U:
213 S->twidCoefRModifier = 256U;
214 #if defined(ARM_MATH_MVEI)
215 status=arm_cfft_init_q31(&(S->cfftInst),16);
216 if (status != ARM_MATH_SUCCESS)
217 {
218 return(status);
219 }
220 #else
221 S->pCfft = &arm_cfft_sR_q31_len16;
222 #endif
223 break;
224 #endif
225 default:
226 /* Reporting argument error if rfftSize is not valid value */
227 status = ARM_MATH_ARGUMENT_ERROR;
228 break;
229 }
230
231 /* return the status of RFFT Init function */
232 return (status);
233 }
234
235 /**
236 @} end of RealFFT group
237 */
238