1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_cfft_radix4_init_f32.c
4 * Description: Radix-4 Decimation in Frequency Floating-point CFFT & CIFFT Initialization 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
32 /**
33 @ingroup groupTransforms
34 */
35
36 /**
37 @addtogroup ComplexFFT
38 @{
39 */
40
41 /**
42 @brief Initialization function for the floating-point CFFT/CIFFT.
43 @deprecated Do not use this function. It has been superceded by \ref arm_cfft_f32 and will be removed in the future.
44 @param[in,out] S points to an instance of the floating-point CFFT/CIFFT structure
45 @param[in] fftLen length of the FFT
46 @param[in] ifftFlag flag that selects transform direction
47 - value = 0: forward transform
48 - value = 1: inverse transform
49 @param[in] bitReverseFlag flag that enables / disables bit reversal of output
50 - value = 0: disables bit reversal of output
51 - value = 1: enables bit reversal of output
52 @return execution status
53 - \ref ARM_MATH_SUCCESS : Operation successful
54 - \ref ARM_MATH_ARGUMENT_ERROR : <code>fftLen</code> is not a supported length
55
56 @par Details
57 The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
58 Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT is calculated
59 @par
60 The parameter <code>bitReverseFlag</code> controls whether output is in normal order or bit reversed order.
61 Set(=1) bitReverseFlag for output to be in normal order otherwise output is in bit reversed order.
62 @par
63 The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
64 @par
65 This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
66 */
67
arm_cfft_radix4_init_f32(arm_cfft_radix4_instance_f32 * S,uint16_t fftLen,uint8_t ifftFlag,uint8_t bitReverseFlag)68 arm_status arm_cfft_radix4_init_f32(
69 arm_cfft_radix4_instance_f32 * S,
70 uint16_t fftLen,
71 uint8_t ifftFlag,
72 uint8_t bitReverseFlag)
73 {
74 /* Initialise the default arm status */
75 arm_status status = ARM_MATH_ARGUMENT_ERROR;
76
77 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_FFT_ALLOW_TABLES)
78
79 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_TWIDDLECOEF_F32_4096)
80
81 /* Initialise the default arm status */
82 status = ARM_MATH_SUCCESS;
83
84 /* Initialise the FFT length */
85 S->fftLen = fftLen;
86
87 /* Initialise the Twiddle coefficient pointer */
88 S->pTwiddle = (float32_t *) twiddleCoef;
89
90 /* Initialise the Flag for selection of CFFT or CIFFT */
91 S->ifftFlag = ifftFlag;
92
93 /* Initialise the Flag for calculation Bit reversal or not */
94 S->bitReverseFlag = bitReverseFlag;
95
96 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_TWIDDLECOEF_F32_4096)
97
98 /* Initializations of structure parameters depending on the FFT length */
99 switch (S->fftLen)
100 {
101
102 case 4096U:
103 /* Initializations of structure parameters for 4096 point FFT */
104
105 /* Initialise the twiddle coef modifier value */
106 S->twidCoefModifier = 1U;
107 /* Initialise the bit reversal table modifier */
108 S->bitRevFactor = 1U;
109 /* Initialise the bit reversal table pointer */
110 S->pBitRevTable = (uint16_t *) armBitRevTable;
111 /* Initialise the 1/fftLen Value */
112 S->onebyfftLen = 0.000244140625;
113 break;
114
115 case 1024U:
116 /* Initializations of structure parameters for 1024 point FFT */
117
118 /* Initialise the twiddle coef modifier value */
119 S->twidCoefModifier = 4U;
120 /* Initialise the bit reversal table modifier */
121 S->bitRevFactor = 4U;
122 /* Initialise the bit reversal table pointer */
123 S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
124 /* Initialise the 1/fftLen Value */
125 S->onebyfftLen = 0.0009765625f;
126 break;
127
128
129 case 256U:
130 /* Initializations of structure parameters for 256 point FFT */
131 S->twidCoefModifier = 16U;
132 S->bitRevFactor = 16U;
133 S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
134 S->onebyfftLen = 0.00390625f;
135 break;
136
137 case 64U:
138 /* Initializations of structure parameters for 64 point FFT */
139 S->twidCoefModifier = 64U;
140 S->bitRevFactor = 64U;
141 S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
142 S->onebyfftLen = 0.015625f;
143 break;
144
145 case 16U:
146 /* Initializations of structure parameters for 16 point FFT */
147 S->twidCoefModifier = 256U;
148 S->bitRevFactor = 256U;
149 S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
150 S->onebyfftLen = 0.0625f;
151 break;
152
153
154 default:
155 /* Reporting argument error if fftSize is not valid value */
156 status = ARM_MATH_ARGUMENT_ERROR;
157 break;
158 }
159 #endif
160 #endif
161 #endif
162
163 return (status);
164 }
165
166 /**
167 @} end of ComplexFFT group
168 */
169
