diff options
Diffstat (limited to 'Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_sparse_q31.c')
| -rw-r--r-- | Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_sparse_q31.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_sparse_q31.c b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_sparse_q31.c new file mode 100644 index 0000000..7c92431 --- /dev/null +++ b/Drivers/CMSIS/DSP/Source/FilteringFunctions/arm_fir_sparse_q31.c @@ -0,0 +1,357 @@ +/* ----------------------------------------------------------------------
+ * Project: CMSIS DSP Library
+ * Title: arm_fir_sparse_q31.c
+ * Description: Q31 sparse FIR filter processing function
+ *
+ * $Date: 18. March 2019
+ * $Revision: V1.6.0
+ *
+ * Target Processor: Cortex-M cores
+ * -------------------------------------------------------------------- */
+/*
+ * Copyright (C) 2010-2019 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_Sparse
+ @{
+ */
+
+/**
+ @brief Processing function for the Q31 sparse FIR filter.
+ @param[in] S points to an instance of the Q31 sparse FIR structure
+ @param[in] pSrc points to the block of input data
+ @param[out] pDst points to the block of output data
+ @param[in] pScratchIn points to a temporary buffer of size blockSize
+ @param[in] blockSize number of input samples to process
+ @return none
+
+ @par Scaling and Overflow Behavior
+ The function is implemented using an internal 32-bit accumulator.
+ The 1.31 x 1.31 multiplications are truncated to 2.30 format.
+ This leads to loss of precision on the intermediate multiplications and provides only a single guard bit.
+ If the accumulator result overflows, it wraps around rather than saturate.
+ In order to avoid overflows the input signal or coefficients must be scaled down by log2(numTaps) bits.
+ */
+
+void arm_fir_sparse_q31(
+ arm_fir_sparse_instance_q31 * S,
+ const q31_t * pSrc,
+ q31_t * pDst,
+ q31_t * pScratchIn,
+ uint32_t blockSize)
+{
+ q31_t *pState = S->pState; /* State pointer */
+ const q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */
+ q31_t *px; /* Scratch buffer pointer */
+ q31_t *py = pState; /* Temporary pointers for state buffer */
+ q31_t *pb = pScratchIn; /* Temporary pointers for scratch buffer */
+ q31_t *pOut; /* Destination pointer */
+ int32_t *pTapDelay = S->pTapDelay; /* Pointer to the array containing offset of the non-zero tap values. */
+ uint32_t delaySize = S->maxDelay + blockSize; /* state length */
+ uint16_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */
+ int32_t readIndex; /* Read index of the state buffer */
+ uint32_t tapCnt, blkCnt; /* loop counters */
+ q31_t coeff = *pCoeffs++; /* Read the first coefficient value */
+ q31_t in;
+ q63_t out; /* Temporary output variable */
+
+
+ /* BlockSize of Input samples are copied into the state buffer */
+ /* StateIndex points to the starting position to write in the state buffer */
+ arm_circularWrite_f32((int32_t *) py, delaySize, &S->stateIndex, 1,
+ (int32_t *) pSrc, 1, blockSize);
+
+ /* Read Index, from where the state buffer should be read, is calculated. */
+ readIndex = (int32_t) (S->stateIndex - blockSize) - *pTapDelay++;
+
+ /* Wraparound of readIndex */
+ if (readIndex < 0)
+ {
+ readIndex += (int32_t) delaySize;
+ }
+
+ /* Working pointer for state buffer is updated */
+ py = pState;
+
+ /* blockSize samples are read from the state buffer */
+ arm_circularRead_f32((int32_t *) py, delaySize, &readIndex, 1,
+ (int32_t *) pb, (int32_t *) pb, blockSize, 1, blockSize);
+
+ /* Working pointer for the scratch buffer of state values */
+ px = pb;
+
+ /* Working pointer for scratch buffer of output values */
+ pOut = pDst;
+
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time. */
+ blkCnt = blockSize >> 2U;
+
+ while (blkCnt > 0U)
+ {
+ /* Perform Multiplications and store in destination buffer */
+ *pOut++ = (q31_t) (((q63_t) *px++ * coeff) >> 32);
+
+ *pOut++ = (q31_t) (((q63_t) *px++ * coeff) >> 32);
+
+ *pOut++ = (q31_t) (((q63_t) *px++ * coeff) >> 32);
+
+ *pOut++ = (q31_t) (((q63_t) *px++ * coeff) >> 32);
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ blkCnt = blockSize % 0x4U;
+
+#else
+
+ /* Initialize blkCnt with number of samples */
+ blkCnt = blockSize;
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ while (blkCnt > 0U)
+ {
+ /* Perform Multiplication and store in destination buffer */
+ *pOut++ = (q31_t) (((q63_t) *px++ * coeff) >> 32);
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Load the coefficient value and
+ * increment the coefficient buffer for the next set of state values */
+ coeff = *pCoeffs++;
+
+ /* Read Index, from where the state buffer should be read, is calculated. */
+ readIndex = (int32_t) (S->stateIndex - blockSize) - *pTapDelay++;
+
+ /* Wraparound of readIndex */
+ if (readIndex < 0)
+ {
+ readIndex += (int32_t) delaySize;
+ }
+
+ /* Loop over the number of taps. */
+ tapCnt = (uint32_t) numTaps - 2U;
+
+ while (tapCnt > 0U)
+ {
+ /* Working pointer for state buffer is updated */
+ py = pState;
+
+ /* blockSize samples are read from the state buffer */
+ arm_circularRead_f32((int32_t *) py, delaySize, &readIndex, 1,
+ (int32_t *) pb, (int32_t *) pb, blockSize, 1, blockSize);
+
+ /* Working pointer for the scratch buffer of state values */
+ px = pb;
+
+ /* Working pointer for scratch buffer of output values */
+ pOut = pDst;
+
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time. */
+ blkCnt = blockSize >> 2U;
+
+ while (blkCnt > 0U)
+ {
+ /* Perform Multiply-Accumulate */
+ out = *pOut;
+ out += ((q63_t) *px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ out = *pOut;
+ out += ((q63_t) *px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ out = *pOut;
+ out += ((q63_t) *px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ out = *pOut;
+ out += ((q63_t) *px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ blkCnt = blockSize % 0x4U;
+
+#else
+
+ /* Initialize blkCnt with number of samples */
+ blkCnt = blockSize;
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ while (blkCnt > 0U)
+ {
+ /* Perform Multiply-Accumulate */
+ out = *pOut;
+ out += ((q63_t) *px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Load the coefficient value and
+ * increment the coefficient buffer for the next set of state values */
+ coeff = *pCoeffs++;
+
+ /* Read Index, from where the state buffer should be read, is calculated. */
+ readIndex = (int32_t) (S->stateIndex - blockSize) - *pTapDelay++;
+
+ /* Wraparound of readIndex */
+ if (readIndex < 0)
+ {
+ readIndex += (int32_t) delaySize;
+ }
+
+ /* Decrement tap loop counter */
+ tapCnt--;
+ }
+
+ /* Compute last tap without the final read of pTapDelay */
+
+ /* Working pointer for state buffer is updated */
+ py = pState;
+
+ /* blockSize samples are read from the state buffer */
+ arm_circularRead_f32((int32_t *) py, delaySize, &readIndex, 1,
+ (int32_t *) pb, (int32_t *) pb, blockSize, 1, blockSize);
+
+ /* Working pointer for the scratch buffer of state values */
+ px = pb;
+
+ /* Working pointer for scratch buffer of output values */
+ pOut = pDst;
+
+
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time. */
+ blkCnt = blockSize >> 2U;
+
+ while (blkCnt > 0U)
+ {
+ /* Perform Multiply-Accumulate */
+ out = *pOut;
+ out += ((q63_t) * px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ out = *pOut;
+ out += ((q63_t) * px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ out = *pOut;
+ out += ((q63_t) * px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ out = *pOut;
+ out += ((q63_t) * px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ blkCnt = blockSize % 0x4U;
+
+#else
+
+ /* Initialize blkCnt with number of samples */
+ blkCnt = blockSize;
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ while (blkCnt > 0U)
+ {
+ /* Perform Multiply-Accumulate */
+ out = *pOut;
+ out += ((q63_t) *px++ * coeff) >> 32;
+ *pOut++ = (q31_t) (out);
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Working output pointer is updated */
+ pOut = pDst;
+
+ /* Output is converted into 1.31 format. */
+#if defined (ARM_MATH_LOOPUNROLL)
+
+ /* Loop unrolling: Compute 4 outputs at a time. */
+ blkCnt = blockSize >> 2U;
+
+ while (blkCnt > 0U)
+ {
+ in = *pOut << 1;
+ *pOut++ = in;
+ in = *pOut << 1;
+ *pOut++ = in;
+ in = *pOut << 1;
+ *pOut++ = in;
+ in = *pOut << 1;
+ *pOut++ = in;
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+ /* Loop unrolling: Compute remaining outputs */
+ blkCnt = blockSize % 0x4U;
+
+#else
+
+ /* Initialize blkCnt with number of samples */
+ blkCnt = blockSize;
+
+#endif /* #if defined (ARM_MATH_LOOPUNROLL) */
+
+ while (blkCnt > 0U)
+ {
+ in = *pOut << 1;
+ *pOut++ = in;
+
+ /* Decrement loop counter */
+ blkCnt--;
+ }
+
+}
+
+/**
+ @} end of FIR_Sparse group
+ */
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