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Diffstat (limited to 'DSP_Lib/Source/FilteringFunctions/arm_fir_sparse_q31.c')
-rw-r--r-- | DSP_Lib/Source/FilteringFunctions/arm_fir_sparse_q31.c | 461 |
1 files changed, 461 insertions, 0 deletions
diff --git a/DSP_Lib/Source/FilteringFunctions/arm_fir_sparse_q31.c b/DSP_Lib/Source/FilteringFunctions/arm_fir_sparse_q31.c new file mode 100644 index 0000000..2183cd3 --- /dev/null +++ b/DSP_Lib/Source/FilteringFunctions/arm_fir_sparse_q31.c @@ -0,0 +1,461 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 19. March 2015 +* $Revision: V.1.4.5 +* +* Project: CMSIS DSP Library +* Title: arm_fir_sparse_q31.c +* +* Description: Q31 sparse FIR filter processing function. +* +* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 +* +* Redistribution and use in source and binary forms, with or without +* modification, are permitted provided that the following conditions +* are met: +* - Redistributions of source code must retain the above copyright +* notice, this list of conditions and the following disclaimer. +* - Redistributions in binary form must reproduce the above copyright +* notice, this list of conditions and the following disclaimer in +* the documentation and/or other materials provided with the +* distribution. +* - Neither the name of ARM LIMITED nor the names of its contributors +* may be used to endorse or promote products derived from this +* software without specific prior written permission. +* +* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +* POSSIBILITY OF SUCH DAMAGE. +* ------------------------------------------------------------------- */ +#include "arm_math.h" + + +/** + * @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 per call. + * @return none. + * + * <b>Scaling and Overflow Behavior:</b> + * \par + * 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, + q31_t * pSrc, + q31_t * pDst, + q31_t * pScratchIn, + uint32_t blockSize) +{ + + q31_t *pState = S->pState; /* State pointer */ + 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 */ + q63_t out; /* Temporary output variable */ + 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; /* Filter order */ + 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; + + + /* 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; + + +#ifndef ARM_MATH_CM0_FAMILY + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + + /* Loop over the blockSize. Unroll by a factor of 4. + * Compute 4 Multiplications at a time. */ + blkCnt = blockSize >> 2; + + while(blkCnt > 0u) + { + /* Perform Multiplications and store in the 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 the loop counter */ + blkCnt--; + } + + /* If the blockSize is not a multiple of 4, + * compute the remaining samples */ + blkCnt = blockSize % 0x4u; + + while(blkCnt > 0u) + { + /* Perform Multiplications and store in the destination buffer */ + *pOut++ = (q31_t) (((q63_t) * px++ * coeff) >> 32); + + /* Decrement the 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; + + /* Loop over the blockSize. Unroll by a factor of 4. + * Compute 4 MACS at a time. */ + blkCnt = blockSize >> 2; + + while(blkCnt > 0u) + { + 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 the loop counter */ + blkCnt--; + } + + /* If the blockSize is not a multiple of 4, + * compute the remaining samples */ + blkCnt = blockSize % 0x4u; + + while(blkCnt > 0u) + { + /* Perform Multiply-Accumulate */ + out = *pOut; + out += ((q63_t) * px++ * coeff) >> 32; + *pOut++ = (q31_t) (out); + + /* Decrement the 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 the 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; + + /* Loop over the blockSize. Unroll by a factor of 4. + * Compute 4 MACS at a time. */ + blkCnt = blockSize >> 2; + + while(blkCnt > 0u) + { + 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 the loop counter */ + blkCnt--; + } + + /* If the blockSize is not a multiple of 4, + * compute the remaining samples */ + blkCnt = blockSize % 0x4u; + + while(blkCnt > 0u) + { + /* Perform Multiply-Accumulate */ + out = *pOut; + out += ((q63_t) * px++ * coeff) >> 32; + *pOut++ = (q31_t) (out); + + /* Decrement the loop counter */ + blkCnt--; + } + + /* Working output pointer is updated */ + pOut = pDst; + + /* Output is converted into 1.31 format. */ + /* Loop over the blockSize. Unroll by a factor of 4. + * process 4 output samples at a time. */ + blkCnt = blockSize >> 2; + + while(blkCnt > 0u) + { + in = *pOut << 1; + *pOut++ = in; + in = *pOut << 1; + *pOut++ = in; + in = *pOut << 1; + *pOut++ = in; + in = *pOut << 1; + *pOut++ = in; + + /* Decrement the loop counter */ + blkCnt--; + } + + /* If the blockSize is not a multiple of 4, + * process the remaining output samples */ + blkCnt = blockSize % 0x4u; + + while(blkCnt > 0u) + { + in = *pOut << 1; + *pOut++ = in; + + /* Decrement the loop counter */ + blkCnt--; + } + +#else + + /* Run the below code for Cortex-M0 */ + blkCnt = blockSize; + + while(blkCnt > 0u) + { + /* Perform Multiplications and store in the destination buffer */ + *pOut++ = (q31_t) (((q63_t) * px++ * coeff) >> 32); + + /* Decrement the 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; + + blkCnt = blockSize; + + while(blkCnt > 0u) + { + /* Perform Multiply-Accumulate */ + out = *pOut; + out += ((q63_t) * px++ * coeff) >> 32; + *pOut++ = (q31_t) (out); + + /* Decrement the 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 the 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; + + blkCnt = blockSize; + + while(blkCnt > 0u) + { + /* Perform Multiply-Accumulate */ + out = *pOut; + out += ((q63_t) * px++ * coeff) >> 32; + *pOut++ = (q31_t) (out); + + /* Decrement the loop counter */ + blkCnt--; + } + + /* Working output pointer is updated */ + pOut = pDst; + + /* Output is converted into 1.31 format. */ + blkCnt = blockSize; + + while(blkCnt > 0u) + { + in = *pOut << 1; + *pOut++ = in; + + /* Decrement the loop counter */ + blkCnt--; + } + +#endif /* #ifndef ARM_MATH_CM0_FAMILY */ + +} + +/** + * @} end of FIR_Sparse group + */ |