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Diffstat (limited to 'DSP_Lib/Source/FilteringFunctions/arm_lms_norm_q31.c')
-rw-r--r-- | DSP_Lib/Source/FilteringFunctions/arm_lms_norm_q31.c | 431 |
1 files changed, 431 insertions, 0 deletions
diff --git a/DSP_Lib/Source/FilteringFunctions/arm_lms_norm_q31.c b/DSP_Lib/Source/FilteringFunctions/arm_lms_norm_q31.c new file mode 100644 index 0000000..3d990e3 --- /dev/null +++ b/DSP_Lib/Source/FilteringFunctions/arm_lms_norm_q31.c @@ -0,0 +1,431 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 19. March 2015 +* $Revision: V.1.4.5 +* +* Project: CMSIS DSP Library +* Title: arm_lms_norm_q31.c +* +* Description: Processing function for the Q31 NLMS filter. +* +* 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" + +/** + * @ingroup groupFilters + */ + +/** + * @addtogroup LMS_NORM + * @{ + */ + +/** +* @brief Processing function for Q31 normalized LMS filter. +* @param[in] *S points to an instance of the Q31 normalized LMS filter structure. +* @param[in] *pSrc points to the block of input data. +* @param[in] *pRef points to the block of reference data. +* @param[out] *pOut points to the block of output data. +* @param[out] *pErr points to the block of error data. +* @param[in] blockSize number of samples to process. +* @return none. +* +* <b>Scaling and Overflow Behavior:</b> +* \par +* The function is implemented using an internal 64-bit accumulator. +* The accumulator has a 2.62 format and maintains full precision of the intermediate +* multiplication results but provides only a single guard bit. +* Thus, if the accumulator result overflows it wraps around rather than clip. +* In order to avoid overflows completely the input signal must be scaled down by +* log2(numTaps) bits. The reference signal should not be scaled down. +* After all multiply-accumulates are performed, the 2.62 accumulator is shifted +* and saturated to 1.31 format to yield the final result. +* The output signal and error signal are in 1.31 format. +* +* \par +* In this filter, filter coefficients are updated for each sample and the +* updation of filter cofficients are saturted. +* +*/ + +void arm_lms_norm_q31( + arm_lms_norm_instance_q31 * S, + q31_t * pSrc, + q31_t * pRef, + q31_t * pOut, + q31_t * pErr, + 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 *px, *pb; /* Temporary pointers for state and coefficient buffers */ + q31_t mu = S->mu; /* Adaptive factor */ + uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */ + uint32_t tapCnt, blkCnt; /* Loop counters */ + q63_t energy; /* Energy of the input */ + q63_t acc; /* Accumulator */ + q31_t e = 0, d = 0; /* error, reference data sample */ + q31_t w = 0, in; /* weight factor and state */ + q31_t x0; /* temporary variable to hold input sample */ +// uint32_t shift = 32u - ((uint32_t) S->postShift + 1u); /* Shift to be applied to the output */ + q31_t errorXmu, oneByEnergy; /* Temporary variables to store error and mu product and reciprocal of energy */ + q31_t postShift; /* Post shift to be applied to weight after reciprocal calculation */ + q31_t coef; /* Temporary variable for coef */ + q31_t acc_l, acc_h; /* temporary input */ + uint32_t uShift = ((uint32_t) S->postShift + 1u); + uint32_t lShift = 32u - uShift; /* Shift to be applied to the output */ + + energy = S->energy; + x0 = S->x0; + + /* S->pState points to buffer which contains previous frame (numTaps - 1) samples */ + /* pStateCurnt points to the location where the new input data should be written */ + pStateCurnt = &(S->pState[(numTaps - 1u)]); + + /* Loop over blockSize number of values */ + blkCnt = blockSize; + + +#ifndef ARM_MATH_CM0_FAMILY + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + + while(blkCnt > 0u) + { + + /* Copy the new input sample into the state buffer */ + *pStateCurnt++ = *pSrc; + + /* Initialize pState pointer */ + px = pState; + + /* Initialize coeff pointer */ + pb = (pCoeffs); + + /* Read the sample from input buffer */ + in = *pSrc++; + + /* Update the energy calculation */ + energy = (q31_t) ((((q63_t) energy << 32) - + (((q63_t) x0 * x0) << 1)) >> 32); + energy = (q31_t) (((((q63_t) in * in) << 1) + (energy << 32)) >> 32); + + /* Set the accumulator to zero */ + acc = 0; + + /* Loop unrolling. Process 4 taps at a time. */ + tapCnt = numTaps >> 2; + + while(tapCnt > 0u) + { + /* Perform the multiply-accumulate */ + acc += ((q63_t) (*px++)) * (*pb++); + acc += ((q63_t) (*px++)) * (*pb++); + acc += ((q63_t) (*px++)) * (*pb++); + acc += ((q63_t) (*px++)) * (*pb++); + + /* 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) + { + /* Perform the multiply-accumulate */ + acc += ((q63_t) (*px++)) * (*pb++); + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Converting the result to 1.31 format */ + /* Calc lower part of acc */ + acc_l = acc & 0xffffffff; + + /* Calc upper part of acc */ + acc_h = (acc >> 32) & 0xffffffff; + + acc = (uint32_t) acc_l >> lShift | acc_h << uShift; + + /* Store the result from accumulator into the destination buffer. */ + *pOut++ = (q31_t) acc; + + /* Compute and store error */ + d = *pRef++; + e = d - (q31_t) acc; + *pErr++ = e; + + /* Calculates the reciprocal of energy */ + postShift = arm_recip_q31(energy + DELTA_Q31, + &oneByEnergy, &S->recipTable[0]); + + /* Calculation of product of (e * mu) */ + errorXmu = (q31_t) (((q63_t) e * mu) >> 31); + + /* Weighting factor for the normalized version */ + w = clip_q63_to_q31(((q63_t) errorXmu * oneByEnergy) >> (31 - postShift)); + + /* Initialize pState pointer */ + px = pState; + + /* Initialize coeff pointer */ + pb = (pCoeffs); + + /* Loop unrolling. Process 4 taps at a time. */ + tapCnt = numTaps >> 2; + + /* Update filter coefficients */ + while(tapCnt > 0u) + { + /* Perform the multiply-accumulate */ + + /* coef is in 2.30 format */ + coef = (q31_t) (((q63_t) w * (*px++)) >> (32)); + /* get coef in 1.31 format by left shifting */ + *pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u)); + /* update coefficient buffer to next coefficient */ + pb++; + + coef = (q31_t) (((q63_t) w * (*px++)) >> (32)); + *pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u)); + pb++; + + coef = (q31_t) (((q63_t) w * (*px++)) >> (32)); + *pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u)); + pb++; + + coef = (q31_t) (((q63_t) w * (*px++)) >> (32)); + *pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u)); + pb++; + + /* 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) + { + /* Perform the multiply-accumulate */ + coef = (q31_t) (((q63_t) w * (*px++)) >> (32)); + *pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u)); + pb++; + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Read the sample from state buffer */ + x0 = *pState; + + /* Advance state pointer by 1 for the next sample */ + pState = pState + 1; + + /* Decrement the loop counter */ + blkCnt--; + } + + /* Save energy and x0 values for the next frame */ + S->energy = (q31_t) energy; + S->x0 = x0; + + /* 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 pState buffer */ + pStateCurnt = S->pState; + + /* Loop unrolling for (numTaps - 1u) samples copy */ + tapCnt = (numTaps - 1u) >> 2u; + + /* copy data */ + while(tapCnt > 0u) + { + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Calculate remaining number of copies */ + tapCnt = (numTaps - 1u) % 0x4u; + + /* Copy the remaining q31_t data */ + while(tapCnt > 0u) + { + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + tapCnt--; + } + +#else + + /* Run the below code for Cortex-M0 */ + + while(blkCnt > 0u) + { + + /* Copy the new input sample into the state buffer */ + *pStateCurnt++ = *pSrc; + + /* Initialize pState pointer */ + px = pState; + + /* Initialize pCoeffs pointer */ + pb = pCoeffs; + + /* Read the sample from input buffer */ + in = *pSrc++; + + /* Update the energy calculation */ + energy = + (q31_t) ((((q63_t) energy << 32) - (((q63_t) x0 * x0) << 1)) >> 32); + energy = (q31_t) (((((q63_t) in * in) << 1) + (energy << 32)) >> 32); + + /* Set the accumulator to zero */ + acc = 0; + + /* Loop over numTaps number of values */ + tapCnt = numTaps; + + while(tapCnt > 0u) + { + /* Perform the multiply-accumulate */ + acc += ((q63_t) (*px++)) * (*pb++); + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Converting the result to 1.31 format */ + /* Converting the result to 1.31 format */ + /* Calc lower part of acc */ + acc_l = acc & 0xffffffff; + + /* Calc upper part of acc */ + acc_h = (acc >> 32) & 0xffffffff; + + acc = (uint32_t) acc_l >> lShift | acc_h << uShift; + + + //acc = (q31_t) (acc >> shift); + + /* Store the result from accumulator into the destination buffer. */ + *pOut++ = (q31_t) acc; + + /* Compute and store error */ + d = *pRef++; + e = d - (q31_t) acc; + *pErr++ = e; + + /* Calculates the reciprocal of energy */ + postShift = + arm_recip_q31(energy + DELTA_Q31, &oneByEnergy, &S->recipTable[0]); + + /* Calculation of product of (e * mu) */ + errorXmu = (q31_t) (((q63_t) e * mu) >> 31); + + /* Weighting factor for the normalized version */ + w = clip_q63_to_q31(((q63_t) errorXmu * oneByEnergy) >> (31 - postShift)); + + /* Initialize pState pointer */ + px = pState; + + /* Initialize coeff pointer */ + pb = (pCoeffs); + + /* Loop over numTaps number of values */ + tapCnt = numTaps; + + while(tapCnt > 0u) + { + /* Perform the multiply-accumulate */ + /* coef is in 2.30 format */ + coef = (q31_t) (((q63_t) w * (*px++)) >> (32)); + /* get coef in 1.31 format by left shifting */ + *pb = clip_q63_to_q31((q63_t) * pb + (coef << 1u)); + /* update coefficient buffer to next coefficient */ + pb++; + + /* Decrement the loop counter */ + tapCnt--; + } + + /* Read the sample from state buffer */ + x0 = *pState; + + /* Advance state pointer by 1 for the next sample */ + pState = pState + 1; + + /* Decrement the loop counter */ + blkCnt--; + } + + /* Save energy and x0 values for the next frame */ + S->energy = (q31_t) energy; + S->x0 = x0; + + /* Processing is complete. Now copy the last numTaps - 1 samples to the + start of the state buffer. This prepares the state buffer for the + next function call. */ + + /* Points to the start of the pState buffer */ + pStateCurnt = S->pState; + + /* Loop for (numTaps - 1u) samples copy */ + tapCnt = (numTaps - 1u); + + /* Copy the remaining q31_t data */ + while(tapCnt > 0u) + { + *pStateCurnt++ = *pState++; + + /* Decrement the loop counter */ + tapCnt--; + } + +#endif /* #ifndef ARM_MATH_CM0_FAMILY */ + +} + +/** + * @} end of LMS_NORM group + */ |