1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_cfft_radix4_init_f16.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_f16.h"
30 #include "arm_common_tables.h"
31 #include "arm_common_tables_f16.h"
32
33 /**
34 @ingroup groupTransforms
35 */
36
37 /**
38 @addtogroup ComplexFFT
39 @{
40 */
41
42 /**
43 @brief Initialization function for the floating-point CFFT/CIFFT.
44 @deprecated Do not use this function. It has been superceded by \ref arm_cfft_f16 and will be removed in the future.
45 @param[in,out] S points to an instance of the floating-point 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
69 #if defined(ARM_FLOAT16_SUPPORTED)
70
arm_cfft_radix4_init_f16(arm_cfft_radix4_instance_f16 * S,uint16_t fftLen,uint8_t ifftFlag,uint8_t bitReverseFlag)71 arm_status arm_cfft_radix4_init_f16(
72 arm_cfft_radix4_instance_f16 * S,
73 uint16_t fftLen,
74 uint8_t ifftFlag,
75 uint8_t bitReverseFlag)
76 {
77 /* Initialise the default arm status */
78 arm_status status = ARM_MATH_ARGUMENT_ERROR;
79
80 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_FFT_ALLOW_TABLES)
81
82 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_TWIDDLECOEF_F16_4096)
83
84 /* Initialise the default arm status */
85 status = ARM_MATH_SUCCESS;
86
87 /* Initialise the FFT length */
88 S->fftLen = fftLen;
89
90 /* Initialise the Twiddle coefficient pointer */
91 S->pTwiddle = (float16_t *) twiddleCoefF16;
92
93 /* Initialise the Flag for selection of CFFT or CIFFT */
94 S->ifftFlag = ifftFlag;
95
96 /* Initialise the Flag for calculation Bit reversal or not */
97 S->bitReverseFlag = bitReverseFlag;
98
99 #if !defined(ARM_DSP_CONFIG_TABLES) || defined(ARM_ALL_FFT_TABLES) || defined(ARM_TABLE_BITREV_1024)
100
101 /* Initializations of structure parameters depending on the FFT length */
102 switch (S->fftLen)
103 {
104
105 case 4096U:
106 /* Initializations of structure parameters for 4096 point FFT */
107
108 /* Initialise the twiddle coef modifier value */
109 S->twidCoefModifier = 1U;
110 /* Initialise the bit reversal table modifier */
111 S->bitRevFactor = 1U;
112 /* Initialise the bit reversal table pointer */
113 S->pBitRevTable = (uint16_t *) armBitRevTable;
114 /* Initialise the 1/fftLen Value */
115 S->onebyfftLen = 0.000244140625;
116 break;
117
118 case 1024U:
119 /* Initializations of structure parameters for 1024 point FFT */
120
121 /* Initialise the twiddle coef modifier value */
122 S->twidCoefModifier = 4U;
123 /* Initialise the bit reversal table modifier */
124 S->bitRevFactor = 4U;
125 /* Initialise the bit reversal table pointer */
126 S->pBitRevTable = (uint16_t *) & armBitRevTable[3];
127 /* Initialise the 1/fftLen Value */
128 S->onebyfftLen = 0.0009765625f;
129 break;
130
131
132 case 256U:
133 /* Initializations of structure parameters for 256 point FFT */
134 S->twidCoefModifier = 16U;
135 S->bitRevFactor = 16U;
136 S->pBitRevTable = (uint16_t *) & armBitRevTable[15];
137 S->onebyfftLen = 0.00390625f;
138 break;
139
140 case 64U:
141 /* Initializations of structure parameters for 64 point FFT */
142 S->twidCoefModifier = 64U;
143 S->bitRevFactor = 64U;
144 S->pBitRevTable = (uint16_t *) & armBitRevTable[63];
145 S->onebyfftLen = 0.015625f;
146 break;
147
148 case 16U:
149 /* Initializations of structure parameters for 16 point FFT */
150 S->twidCoefModifier = 256U;
151 S->bitRevFactor = 256U;
152 S->pBitRevTable = (uint16_t *) & armBitRevTable[255];
153 S->onebyfftLen = 0.0625f;
154 break;
155
156
157 default:
158 /* Reporting argument error if fftSize is not valid value */
159 status = ARM_MATH_ARGUMENT_ERROR;
160 break;
161 }
162
163 #endif
164 #endif
165 #endif
166 return (status);
167 }
168 #endif /* #if defined(ARM_FLOAT16_SUPPORTED) */
169 /**
170 @} end of ComplexFFT group
171 */
172