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Diffstat (limited to 'tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_lattice_q31.c')
-rw-r--r-- | tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_lattice_q31.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_lattice_q31.c b/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_lattice_q31.c new file mode 100644 index 0000000000..c0ddf96932 --- /dev/null +++ b/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_lattice_q31.c @@ -0,0 +1,353 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2013 ARM Limited. All rights reserved. +* +* $Date: 17. January 2013 +* $Revision: V1.4.1 +* +* Project: CMSIS DSP Library +* Title: arm_fir_lattice_q31.c +* +* Description: Q31 FIR lattice 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" + +/** + * @ingroup groupFilters + */ + +/** + * @addtogroup FIR_Lattice + * @{ + */ + + +/** + * @brief Processing function for the Q31 FIR lattice filter. + * @param[in] *S points to an instance of the Q31 FIR lattice 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 samples to process. + * @return none. + * + * @details + * <b>Scaling and Overflow Behavior:</b> + * In order to avoid overflows the input signal must be scaled down by 2*log2(numStages) bits. + */ + +#ifndef ARM_MATH_CM0_FAMILY + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + +void arm_fir_lattice_q31( + const arm_fir_lattice_instance_q31 * S, + q31_t * pSrc, + q31_t * pDst, + uint32_t blockSize) +{ + q31_t *pState; /* State pointer */ + q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + q31_t *px; /* temporary state pointer */ + q31_t *pk; /* temporary coefficient pointer */ + q31_t fcurr1, fnext1, gcurr1 = 0, gnext1; /* temporary variables for first sample in loop unrolling */ + q31_t fcurr2, fnext2, gnext2; /* temporary variables for second sample in loop unrolling */ + uint32_t numStages = S->numStages; /* Length of the filter */ + uint32_t blkCnt, stageCnt; /* temporary variables for counts */ + q31_t k; + + pState = &S->pState[0]; + + blkCnt = blockSize >> 1u; + + /* First part of the processing with loop unrolling. Compute 2 outputs at a time. + a second loop below computes the remaining 1 sample. */ + while(blkCnt > 0u) + { + /* f0(n) = x(n) */ + fcurr1 = *pSrc++; + + /* f0(n) = x(n) */ + fcurr2 = *pSrc++; + + /* Initialize coeff pointer */ + pk = (pCoeffs); + + /* Initialize state pointer */ + px = pState; + + /* read g0(n - 1) from state buffer */ + gcurr1 = *px; + + /* Read the reflection coefficient */ + k = *pk++; + + /* for sample 1 processing */ + /* f1(n) = f0(n) + K1 * g0(n-1) */ + fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32); + + /* g1(n) = f0(n) * K1 + g0(n-1) */ + gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32); + fnext1 = fcurr1 + (fnext1 << 1u); + gnext1 = gcurr1 + (gnext1 << 1u); + + /* for sample 1 processing */ + /* f1(n) = f0(n) + K1 * g0(n-1) */ + fnext2 = (q31_t) (((q63_t) fcurr1 * k) >> 32); + + /* g1(n) = f0(n) * K1 + g0(n-1) */ + gnext2 = (q31_t) (((q63_t) fcurr2 * (k)) >> 32); + fnext2 = fcurr2 + (fnext2 << 1u); + gnext2 = fcurr1 + (gnext2 << 1u); + + /* save g1(n) in state buffer */ + *px++ = fcurr2; + + /* f1(n) is saved in fcurr1 + for next stage processing */ + fcurr1 = fnext1; + fcurr2 = fnext2; + + stageCnt = (numStages - 1u); + + /* stage loop */ + while(stageCnt > 0u) + { + + /* Read the reflection coefficient */ + k = *pk++; + + /* read g2(n) from state buffer */ + gcurr1 = *px; + + /* save g1(n) in state buffer */ + *px++ = gnext2; + + /* Sample processing for K2, K3.... */ + /* f2(n) = f1(n) + K2 * g1(n-1) */ + fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32); + fnext2 = (q31_t) (((q63_t) gnext1 * k) >> 32); + + fnext1 = fcurr1 + (fnext1 << 1u); + fnext2 = fcurr2 + (fnext2 << 1u); + + /* g2(n) = f1(n) * K2 + g1(n-1) */ + gnext2 = (q31_t) (((q63_t) fcurr2 * (k)) >> 32); + gnext2 = gnext1 + (gnext2 << 1u); + + /* g2(n) = f1(n) * K2 + g1(n-1) */ + gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32); + gnext1 = gcurr1 + (gnext1 << 1u); + + /* f1(n) is saved in fcurr1 + for next stage processing */ + fcurr1 = fnext1; + fcurr2 = fnext2; + + stageCnt--; + + } + + /* y(n) = fN(n) */ + *pDst++ = fcurr1; + *pDst++ = fcurr2; + + blkCnt--; + + } + + /* If the blockSize is not a multiple of 4, compute any remaining output samples here. + ** No loop unrolling is used. */ + blkCnt = blockSize % 0x2u; + + while(blkCnt > 0u) + { + /* f0(n) = x(n) */ + fcurr1 = *pSrc++; + + /* Initialize coeff pointer */ + pk = (pCoeffs); + + /* Initialize state pointer */ + px = pState; + + /* read g0(n - 1) from state buffer */ + gcurr1 = *px; + + /* Read the reflection coefficient */ + k = *pk++; + + /* for sample 1 processing */ + /* f1(n) = f0(n) + K1 * g0(n-1) */ + fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32); + fnext1 = fcurr1 + (fnext1 << 1u); + + /* g1(n) = f0(n) * K1 + g0(n-1) */ + gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32); + gnext1 = gcurr1 + (gnext1 << 1u); + + /* save g1(n) in state buffer */ + *px++ = fcurr1; + + /* f1(n) is saved in fcurr1 + for next stage processing */ + fcurr1 = fnext1; + + stageCnt = (numStages - 1u); + + /* stage loop */ + while(stageCnt > 0u) + { + /* Read the reflection coefficient */ + k = *pk++; + + /* read g2(n) from state buffer */ + gcurr1 = *px; + + /* save g1(n) in state buffer */ + *px++ = gnext1; + + /* Sample processing for K2, K3.... */ + /* f2(n) = f1(n) + K2 * g1(n-1) */ + fnext1 = (q31_t) (((q63_t) gcurr1 * k) >> 32); + fnext1 = fcurr1 + (fnext1 << 1u); + + /* g2(n) = f1(n) * K2 + g1(n-1) */ + gnext1 = (q31_t) (((q63_t) fcurr1 * (k)) >> 32); + gnext1 = gcurr1 + (gnext1 << 1u); + + /* f1(n) is saved in fcurr1 + for next stage processing */ + fcurr1 = fnext1; + + stageCnt--; + + } + + + /* y(n) = fN(n) */ + *pDst++ = fcurr1; + + blkCnt--; + + } + + +} + + +#else + +/* Run the below code for Cortex-M0 */ + +void arm_fir_lattice_q31( + const arm_fir_lattice_instance_q31 * S, + q31_t * pSrc, + q31_t * pDst, + uint32_t blockSize) +{ + q31_t *pState; /* State pointer */ + q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + q31_t *px; /* temporary state pointer */ + q31_t *pk; /* temporary coefficient pointer */ + q31_t fcurr, fnext, gcurr, gnext; /* temporary variables */ + uint32_t numStages = S->numStages; /* Length of the filter */ + uint32_t blkCnt, stageCnt; /* temporary variables for counts */ + + pState = &S->pState[0]; + + blkCnt = blockSize; + + while(blkCnt > 0u) + { + /* f0(n) = x(n) */ + fcurr = *pSrc++; + + /* Initialize coeff pointer */ + pk = (pCoeffs); + + /* Initialize state pointer */ + px = pState; + + /* read g0(n-1) from state buffer */ + gcurr = *px; + + /* for sample 1 processing */ + /* f1(n) = f0(n) + K1 * g0(n-1) */ + fnext = (q31_t) (((q63_t) gcurr * (*pk)) >> 31) + fcurr; + /* g1(n) = f0(n) * K1 + g0(n-1) */ + gnext = (q31_t) (((q63_t) fcurr * (*pk++)) >> 31) + gcurr; + /* save g1(n) in state buffer */ + *px++ = fcurr; + + /* f1(n) is saved in fcurr1 + for next stage processing */ + fcurr = fnext; + + stageCnt = (numStages - 1u); + + /* stage loop */ + while(stageCnt > 0u) + { + /* read g2(n) from state buffer */ + gcurr = *px; + + /* save g1(n) in state buffer */ + *px++ = gnext; + + /* Sample processing for K2, K3.... */ + /* f2(n) = f1(n) + K2 * g1(n-1) */ + fnext = (q31_t) (((q63_t) gcurr * (*pk)) >> 31) + fcurr; + /* g2(n) = f1(n) * K2 + g1(n-1) */ + gnext = (q31_t) (((q63_t) fcurr * (*pk++)) >> 31) + gcurr; + + /* f1(n) is saved in fcurr1 + for next stage processing */ + fcurr = fnext; + + stageCnt--; + + } + + /* y(n) = fN(n) */ + *pDst++ = fcurr; + + blkCnt--; + + } + +} + +#endif /* #ifndef ARM_MATH_CM0_FAMILY */ + + +/** + * @} end of FIR_Lattice group + */ |