diff options
author | Clyne Sullivan <clyne@bitgloo.com> | 2025-01-29 21:34:25 -0500 |
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committer | Clyne Sullivan <clyne@bitgloo.com> | 2025-01-29 21:34:25 -0500 |
commit | 5b81bc8ccbd342b8566d88fc9f17a73aec03b5b6 (patch) | |
tree | cc57486912cfa74c6440d8b97c28f451ec787d78 /Drivers/CMSIS/DSP/Source/TransformFunctions/arm_bitreversal.c |
initial commit
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/TransformFunctions/arm_bitreversal.c')
-rw-r--r-- | Drivers/CMSIS/DSP/Source/TransformFunctions/arm_bitreversal.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_bitreversal.c b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_bitreversal.c new file mode 100644 index 0000000..687a9e8 --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/TransformFunctions/arm_bitreversal.c @@ -0,0 +1,230 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_bitreversal.c + * Description: Bitreversal functions + * + * $Date: 23 April 2021 + * $Revision: V1.9.0 + * + * Target Processor: Cortex-M and Cortex-A cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved. + * + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the License); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an AS IS BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "dsp/transform_functions.h" +#include "arm_common_tables.h" + + +/** + @brief In-place floating-point bit reversal function. + @param[in,out] pSrc points to in-place floating-point data buffer + @param[in] fftSize length of FFT + @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table + @param[in] pBitRevTab points to bit reversal table + @return none + */ + +void arm_bitreversal_f32( + float32_t * pSrc, + uint16_t fftSize, + uint16_t bitRevFactor, + const uint16_t * pBitRevTab) +{ + uint16_t fftLenBy2, fftLenBy2p1; + uint16_t i, j; + float32_t in; + + /* Initializations */ + j = 0U; + fftLenBy2 = fftSize >> 1U; + fftLenBy2p1 = (fftSize >> 1U) + 1U; + + /* Bit Reversal Implementation */ + for (i = 0U; i <= (fftLenBy2 - 2U); i += 2U) + { + if (i < j) + { + /* pSrc[i] <-> pSrc[j]; */ + in = pSrc[2U * i]; + pSrc[2U * i] = pSrc[2U * j]; + pSrc[2U * j] = in; + + /* pSrc[i+1U] <-> pSrc[j+1U] */ + in = pSrc[(2U * i) + 1U]; + pSrc[(2U * i) + 1U] = pSrc[(2U * j) + 1U]; + pSrc[(2U * j) + 1U] = in; + + /* pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */ + in = pSrc[2U * (i + fftLenBy2p1)]; + pSrc[2U * (i + fftLenBy2p1)] = pSrc[2U * (j + fftLenBy2p1)]; + pSrc[2U * (j + fftLenBy2p1)] = in; + + /* pSrc[i+fftLenBy2p1+1U] <-> pSrc[j+fftLenBy2p1+1U] */ + in = pSrc[(2U * (i + fftLenBy2p1)) + 1U]; + pSrc[(2U * (i + fftLenBy2p1)) + 1U] = + pSrc[(2U * (j + fftLenBy2p1)) + 1U]; + pSrc[(2U * (j + fftLenBy2p1)) + 1U] = in; + + } + + /* pSrc[i+1U] <-> pSrc[j+1U] */ + in = pSrc[2U * (i + 1U)]; + pSrc[2U * (i + 1U)] = pSrc[2U * (j + fftLenBy2)]; + pSrc[2U * (j + fftLenBy2)] = in; + + /* pSrc[i+2U] <-> pSrc[j+2U] */ + in = pSrc[(2U * (i + 1U)) + 1U]; + pSrc[(2U * (i + 1U)) + 1U] = pSrc[(2U * (j + fftLenBy2)) + 1U]; + pSrc[(2U * (j + fftLenBy2)) + 1U] = in; + + /* Reading the index for the bit reversal */ + j = *pBitRevTab; + + /* Updating the bit reversal index depending on the fft length */ + pBitRevTab += bitRevFactor; + } +} + + +/** + @brief In-place Q31 bit reversal function. + @param[in,out] pSrc points to in-place Q31 data buffer. + @param[in] fftLen length of FFT. + @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table + @param[in] pBitRevTab points to bit reversal table + @return none +*/ + +void arm_bitreversal_q31( + q31_t * pSrc, + uint32_t fftLen, + uint16_t bitRevFactor, + const uint16_t * pBitRevTab) +{ + uint32_t fftLenBy2, fftLenBy2p1, i, j; + q31_t in; + + /* Initializations */ + j = 0U; + fftLenBy2 = fftLen / 2U; + fftLenBy2p1 = (fftLen / 2U) + 1U; + + /* Bit Reversal Implementation */ + for (i = 0U; i <= (fftLenBy2 - 2U); i += 2U) + { + if (i < j) + { + /* pSrc[i] <-> pSrc[j]; */ + in = pSrc[2U * i]; + pSrc[2U * i] = pSrc[2U * j]; + pSrc[2U * j] = in; + + /* pSrc[i+1U] <-> pSrc[j+1U] */ + in = pSrc[(2U * i) + 1U]; + pSrc[(2U * i) + 1U] = pSrc[(2U * j) + 1U]; + pSrc[(2U * j) + 1U] = in; + + /* pSrc[i+fftLenBy2p1] <-> pSrc[j+fftLenBy2p1] */ + in = pSrc[2U * (i + fftLenBy2p1)]; + pSrc[2U * (i + fftLenBy2p1)] = pSrc[2U * (j + fftLenBy2p1)]; + pSrc[2U * (j + fftLenBy2p1)] = in; + + /* pSrc[i+fftLenBy2p1+1U] <-> pSrc[j+fftLenBy2p1+1U] */ + in = pSrc[(2U * (i + fftLenBy2p1)) + 1U]; + pSrc[(2U * (i + fftLenBy2p1)) + 1U] = + pSrc[(2U * (j + fftLenBy2p1)) + 1U]; + pSrc[(2U * (j + fftLenBy2p1)) + 1U] = in; + + } + + /* pSrc[i+1U] <-> pSrc[j+1U] */ + in = pSrc[2U * (i + 1U)]; + pSrc[2U * (i + 1U)] = pSrc[2U * (j + fftLenBy2)]; + pSrc[2U * (j + fftLenBy2)] = in; + + /* pSrc[i+2U] <-> pSrc[j+2U] */ + in = pSrc[(2U * (i + 1U)) + 1U]; + pSrc[(2U * (i + 1U)) + 1U] = pSrc[(2U * (j + fftLenBy2)) + 1U]; + pSrc[(2U * (j + fftLenBy2)) + 1U] = in; + + /* Reading the index for the bit reversal */ + j = *pBitRevTab; + + /* Updating the bit reversal index depending on the fft length */ + pBitRevTab += bitRevFactor; + } +} + + + +/** + @brief In-place Q15 bit reversal function. + @param[in,out] pSrc16 points to in-place Q15 data buffer + @param[in] fftLen length of FFT + @param[in] bitRevFactor bit reversal modifier that supports different size FFTs with the same bit reversal table + @param[in] pBitRevTab points to bit reversal table + @return none +*/ + +void arm_bitreversal_q15( + q15_t * pSrc16, + uint32_t fftLen, + uint16_t bitRevFactor, + const uint16_t * pBitRevTab) +{ + q31_t *pSrc = (q31_t *) pSrc16; + q31_t in; + uint32_t fftLenBy2, fftLenBy2p1; + uint32_t i, j; + + /* Initializations */ + j = 0U; + fftLenBy2 = fftLen / 2U; + fftLenBy2p1 = (fftLen / 2U) + 1U; + + /* Bit Reversal Implementation */ + for (i = 0U; i <= (fftLenBy2 - 2U); i += 2U) + { + if (i < j) + { + /* pSrc[i] <-> pSrc[j]; */ + /* pSrc[i+1U] <-> pSrc[j+1U] */ + in = pSrc[i]; + pSrc[i] = pSrc[j]; + pSrc[j] = in; + + /* pSrc[i + fftLenBy2p1] <-> pSrc[j + fftLenBy2p1]; */ + /* pSrc[i + fftLenBy2p1+1U] <-> pSrc[j + fftLenBy2p1+1U] */ + in = pSrc[i + fftLenBy2p1]; + pSrc[i + fftLenBy2p1] = pSrc[j + fftLenBy2p1]; + pSrc[j + fftLenBy2p1] = in; + } + + /* pSrc[i+1U] <-> pSrc[j+fftLenBy2]; */ + /* pSrc[i+2] <-> pSrc[j+fftLenBy2+1U] */ + in = pSrc[i + 1U]; + pSrc[i + 1U] = pSrc[j + fftLenBy2]; + pSrc[j + fftLenBy2] = in; + + /* Reading the index for the bit reversal */ + j = *pBitRevTab; + + /* Updating the bit reversal index depending on the fft length */ + pBitRevTab += bitRevFactor; + } +} |