1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_cfft_radix4_init_q31.c
4 * Description: Radix-4 Decimation in Frequency Q31 FFT & IFFT 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
43 @brief Initialization function for the Q31 CFFT/CIFFT.
44 @deprecated Do not use this function. It has been superseded by \ref arm_cfft_q31 and will be removed in the future.
45 @param[in,out] S points to an instance of the Q31 CFFT/CIFFT structure.
46 @param[in] fftLen length of the FFT.
47 @param[in] ifftFlag flag that selects transform direction
48 - value = 0: forward transform
49 - value = 1: inverse transform
50 @param[in] bitReverseFlag flag that enables / disables bit reversal of output
51 - value = 0: disables bit reversal of output
52 - value = 1: enables bit reversal of output
53 @return execution status
54 - \ref ARM_MATH_SUCCESS : Operation successful
55 - \ref ARM_MATH_ARGUMENT_ERROR : <code>fftLen</code> is not a supported length
56
57 @par Details
58 The parameter <code>ifftFlag</code> controls whether a forward or inverse transform is computed.
59 Set(=1) ifftFlag for calculation of CIFFT otherwise CFFT 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 The parameter <code>fftLen</code> Specifies length of CFFT/CIFFT process. Supported FFT Lengths are 16, 64, 256, 1024.
65 @par
66 This Function also initializes Twiddle factor table pointer and Bit reversal table pointer.
67 */
68
arm_cfft_radix4_init_q31(arm_cfft_radix4_instance_q31 * S,uint16_t fftLen,uint8_t ifftFlag,uint8_t bitReverseFlag)69 arm_status arm_cfft_radix4_init_q31(
70 arm_cfft_radix4_instance_q31 * S,
71 uint16_t fftLen,
72 uint8_t ifftFlag,
73 uint8_t bitReverseFlag)
74 {
75
76 /* Initialise the default arm status */
77 arm_status status = ARM_MATH_ARGUMENT_ERROR;
78
79 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_FFT_ALLOW_TABLES)
80
81 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_TWIDDLECOEF_Q31_4096)
82
83 /* Initialise the default arm status */
84 status = ARM_MATH_SUCCESS;
85 /* Initialise the FFT length */
86 S->fftLen = fftLen;
87 /* Initialise the Twiddle coefficient pointer */
88 S->pTwiddle = (q31_t *) twiddleCoef_4096_q31;
89 /* Initialise the Flag for selection of CFFT or CIFFT */
90 S->ifftFlag = ifftFlag;
91 /* Initialise the Flag for calculation Bit reversal or not */
92 S->bitReverseFlag = bitReverseFlag;
93
94 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_BITREV_1024)
95
96 /* Initializations of Instance structure depending on the FFT length */
97 switch (S->fftLen)
98 {
99 /* Initializations of structure parameters for 4096 point FFT */
100 case 4096U:
101 /* Initialise the twiddle coef modifier value */
102 S->twidCoefModifier = 1U;
103 /* Initialise the bit reversal table modifier */
104 S->bitRevFactor = 1U;
105 /* Initialise the bit reversal table pointer */
106 S->pBitRevTable = (uint16_t *) armBitRevTable;
107 break;
108
109 /* Initializations of structure parameters for 1024 point FFT */
110 case 1024U:
111 /* Initialise the twiddle coef modifier value */
112 S->twidCoefModifier = 4U;
113 /* Initialise the bit reversal table modifier */
114 S->bitRevFactor = 4U;
115 /* Initialise the bit reversal table pointer */
116 S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
117 break;
118
119 case 256U:
120 /* Initializations of structure parameters for 256 point FFT */
121 S->twidCoefModifier = 16U;
122 S->bitRevFactor = 16U;
123 S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
124 break;
125
126 case 64U:
127 /* Initializations of structure parameters for 64 point FFT */
128 S->twidCoefModifier = 64U;
129 S->bitRevFactor = 64U;
130 S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
131 break;
132
133 case 16U:
134 /* Initializations of structure parameters for 16 point FFT */
135 S->twidCoefModifier = 256U;
136 S->bitRevFactor = 256U;
137 S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
138 break;
139
140 default:
141 /* Reporting argument error if fftSize is not valid value */
142 status = ARM_MATH_ARGUMENT_ERROR;
143 break;
144 }
145
146 #endif
147 #endif
148 #endif
149 return (status);
150 }
151
152 /**
153 @} end of ComplexFFT group
154 */
155