From 6ab94e0b318884bbcb95e2ea3835f951502e1d99 Mon Sep 17 00:00:00 2001 From: jaseg Date: Wed, 14 Oct 2020 12:47:28 +0200 Subject: Move firmware into subdirectory --- .../FilteringFunctions/arm_fir_decimate_fast_q31.c | 339 +++++++++++++++++++++ 1 file changed, 339 insertions(+) create mode 100644 fw/cdc-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_decimate_fast_q31.c (limited to 'fw/cdc-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_decimate_fast_q31.c') diff --git a/fw/cdc-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_decimate_fast_q31.c b/fw/cdc-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_decimate_fast_q31.c new file mode 100644 index 0000000..46b7d3d --- /dev/null +++ b/fw/cdc-dials/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_decimate_fast_q31.c @@ -0,0 +1,339 @@ +/* ---------------------------------------------------------------------- + * Project: CMSIS DSP Library + * Title: arm_fir_decimate_fast_q31.c + * Description: Fast Q31 FIR Decimator + * + * $Date: 27. January 2017 + * $Revision: V.1.5.1 + * + * Target Processor: Cortex-M cores + * -------------------------------------------------------------------- */ +/* + * Copyright (C) 2010-2017 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 "arm_math.h" + +/** + * @ingroup groupFilters + */ + +/** + * @addtogroup FIR_decimate + * @{ + */ + +/** + * @brief Processing function for the Q31 FIR decimator (fast variant) for Cortex-M3 and Cortex-M4. + * @param[in] *S points to an instance of the Q31 FIR decimator structure. + * @param[in] *pSrc points to the block of input data. + * @param[out] *pDst points to the block of output data + * @param[in] blockSize number of input samples to process per call. + * @return none + * + * Scaling and Overflow Behavior: + * + * \par + * This function is optimized for speed at the expense of fixed-point precision and overflow protection. + * The result of each 1.31 x 1.31 multiplication is truncated to 2.30 format. + * These intermediate results are added to a 2.30 accumulator. + * Finally, the accumulator is saturated and converted to a 1.31 result. + * The fast version has the same overflow behavior as the standard version and provides less precision since it discards the low 32 bits of each multiplication result. + * In order to avoid overflows completely the input signal must be scaled down by log2(numTaps) bits (where log2 is read as log to the base 2). + * + * \par + * Refer to the function arm_fir_decimate_q31() for a slower implementation of this function which uses a 64-bit accumulator to provide higher precision. + * Both the slow and the fast versions use the same instance structure. + * Use the function arm_fir_decimate_init_q31() to initialize the filter structure. + */ + +void arm_fir_decimate_fast_q31( + arm_fir_decimate_instance_q31 * S, + q31_t * pSrc, + q31_t * pDst, + uint32_t blockSize) +{ + q31_t *pState = S->pState; /* State pointer */ + q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + q31_t *pStateCurnt; /* Points to the current sample of the state */ + q31_t x0, c0; /* Temporary variables to hold state and coefficient values */ + q31_t *px; /* Temporary pointers for state buffer */ + q31_t *pb; /* Temporary pointers for coefficient buffer */ + q31_t sum0; /* Accumulator */ + uint32_t numTaps = S->numTaps; /* Number of taps */ + uint32_t i, tapCnt, blkCnt, outBlockSize = blockSize / S->M; /* Loop counters */ + uint32_t blkCntN2; + q31_t x1; + q31_t acc0, acc1; + q31_t *px0, *px1; + + /* S->pState buffer contains previous frame (numTaps - 1) samples */ + /* pStateCurnt points to the location where the new input data should be written */ + pStateCurnt = S->pState + (numTaps - 1U); + + /* Total number of output samples to be computed */ + + blkCnt = outBlockSize / 2; + blkCntN2 = outBlockSize - (2 * blkCnt); + + while (blkCnt > 0U) + { + /* Copy decimation factor number of new input samples into the state buffer */ + i = 2 * S->M; + + do + { + *pStateCurnt++ = *pSrc++; + + } while (--i); + + /* Set accumulator to zero */ + acc0 = 0; + acc1 = 0; + + /* Initialize state pointer */ + px0 = pState; + px1 = pState + S->M; + + /* Initialize coeff pointer */ + pb = pCoeffs; + + /* Loop unrolling. Process 4 taps at a time. */ + tapCnt = numTaps >> 2; + + /* Loop over the number of taps. Unroll by a factor of 4. + ** Repeat until we've computed numTaps-4 coefficients. */ + while (tapCnt > 0U) + { + /* Read the b[numTaps-1] coefficient */ + c0 = *(pb); + + /* Read x[n-numTaps-1] for sample 0 sample 1 */ + x0 = *(px0); + x1 = *(px1); + + /* Perform the multiply-accumulate */ + acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32); + acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32); + + /* Read the b[numTaps-2] coefficient */ + c0 = *(pb + 1U); + + /* Read x[n-numTaps-2] for sample 0 sample 1 */ + x0 = *(px0 + 1U); + x1 = *(px1 + 1U); + + /* Perform the multiply-accumulate */ + acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32); + acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32); + + /* Read the b[numTaps-3] coefficient */ + c0 = *(pb + 2U); + + /* Read x[n-numTaps-3] for sample 0 sample 1 */ + x0 = *(px0 + 2U); + x1 = *(px1 + 2U); + pb += 4U; + + /* Perform the multiply-accumulate */ + acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32); + acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32); + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb - 1U); + + /* Read x[n-numTaps-4] for sample 0 sample 1 */ + x0 = *(px0 + 3U); + x1 = *(px1 + 3U); + + + /* Perform the multiply-accumulate */ + acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32); + acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32); + + /* update state pointers */ + px0 += 4U; + px1 += 4U; + + /* Decrement the loop counter */ + tapCnt--; + } + + /* If the filter length is not a multiple of 4, compute the remaining filter taps */ + tapCnt = numTaps % 0x4U; + + while (tapCnt > 0U) + { + /* Read coefficients */ + c0 = *(pb++); + + /* Fetch 1 state variable */ + x0 = *(px0++); + x1 = *(px1++); + + /* Perform the multiply-accumulate */ + acc0 = (q31_t) ((((q63_t) acc0 << 32) + ((q63_t) x0 * c0)) >> 32); + acc1 = (q31_t) ((((q63_t) acc1 << 32) + ((q63_t) x1 * c0)) >> 32); + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Advance the state pointer by the decimation factor + * to process the next group of decimation factor number samples */ + pState = pState + S->M * 2; + + /* The result is in the accumulator, store in the destination buffer. */ + *pDst++ = (q31_t) (acc0 << 1); + *pDst++ = (q31_t) (acc1 << 1); + + /* Decrement the loop counter */ + blkCnt--; + } + + while (blkCntN2 > 0U) + { + /* Copy decimation factor number of new input samples into the state buffer */ + i = S->M; + + do + { + *pStateCurnt++ = *pSrc++; + + } while (--i); + + /* Set accumulator to zero */ + sum0 = 0; + + /* Initialize state pointer */ + px = pState; + + /* Initialize coeff pointer */ + pb = pCoeffs; + + /* Loop unrolling. Process 4 taps at a time. */ + tapCnt = numTaps >> 2; + + /* Loop over the number of taps. Unroll by a factor of 4. + ** Repeat until we've computed numTaps-4 coefficients. */ + while (tapCnt > 0U) + { + /* Read the b[numTaps-1] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-1] sample */ + x0 = *(px++); + + /* Perform the multiply-accumulate */ + sum0 = (q31_t) ((((q63_t) sum0 << 32) + ((q63_t) x0 * c0)) >> 32); + + /* Read the b[numTaps-2] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-2] sample */ + x0 = *(px++); + + /* Perform the multiply-accumulate */ + sum0 = (q31_t) ((((q63_t) sum0 << 32) + ((q63_t) x0 * c0)) >> 32); + + /* Read the b[numTaps-3] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-3] sample */ + x0 = *(px++); + + /* Perform the multiply-accumulate */ + sum0 = (q31_t) ((((q63_t) sum0 << 32) + ((q63_t) x0 * c0)) >> 32); + + /* Read the b[numTaps-4] coefficient */ + c0 = *(pb++); + + /* Read x[n-numTaps-4] sample */ + x0 = *(px++); + + /* Perform the multiply-accumulate */ + sum0 = (q31_t) ((((q63_t) sum0 << 32) + ((q63_t) x0 * c0)) >> 32); + + /* Decrement the loop counter */ + tapCnt--; + } + + /* If the filter length is not a multiple of 4, compute the remaining filter taps */ + tapCnt = numTaps % 0x4U; + + while (tapCnt > 0U) + { + /* Read coefficients */ + c0 = *(pb++); + + /* Fetch 1 state variable */ + x0 = *(px++); + + /* Perform the multiply-accumulate */ + sum0 = (q31_t) ((((q63_t) sum0 << 32) + ((q63_t) x0 * c0)) >> 32); + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Advance the state pointer by the decimation factor + * to process the next group of decimation factor number samples */ + pState = pState + S->M; + + /* The result is in the accumulator, store in the destination buffer. */ + *pDst++ = (q31_t) (sum0 << 1); + + /* Decrement the loop counter */ + blkCntN2--; + } + + /* Processing is complete. + ** Now copy the last numTaps - 1 samples to the satrt of the state buffer. + ** This prepares the state buffer for the next function call. */ + + /* Points to the start of the state buffer */ + pStateCurnt = S->pState; + + i = (numTaps - 1U) >> 2U; + + /* copy data */ + while (i > 0U) + { + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + i--; + } + + i = (numTaps - 1U) % 0x04U; + + /* copy data */ + while (i > 0U) + { + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + i--; + } +} + +/** + * @} end of FIR_decimate group + */ -- cgit