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Diffstat (limited to 'platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_lattice_q15.c')
| -rw-r--r-- | platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_lattice_q15.c | 536 |
1 files changed, 536 insertions, 0 deletions
diff --git a/platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_lattice_q15.c b/platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_lattice_q15.c new file mode 100644 index 0000000..7de00b2 --- /dev/null +++ b/platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_lattice_q15.c @@ -0,0 +1,536 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 12. March 2014 +* $Revision: V1.4.4 +* +* Project: CMSIS DSP Library +* Title: arm_fir_lattice_q15.c +* +* Description: Q15 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 Q15 FIR lattice filter. + * @param[in] *S points to an instance of the Q15 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. + */ + +void arm_fir_lattice_q15( + const arm_fir_lattice_instance_q15 * S, + q15_t * pSrc, + q15_t * pDst, + uint32_t blockSize) +{ + q15_t *pState; /* State pointer */ + q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ + q15_t *px; /* temporary state pointer */ + q15_t *pk; /* temporary coefficient pointer */ + + +#ifndef ARM_MATH_CM0_FAMILY + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + + q31_t fcurnt1, fnext1, gcurnt1 = 0, gnext1; /* temporary variables for first sample in loop unrolling */ + q31_t fcurnt2, fnext2, gnext2; /* temporary variables for second sample in loop unrolling */ + q31_t fcurnt3, fnext3, gnext3; /* temporary variables for third sample in loop unrolling */ + q31_t fcurnt4, fnext4, gnext4; /* temporary variables for fourth sample in loop unrolling */ + uint32_t numStages = S->numStages; /* Number of stages in the filter */ + uint32_t blkCnt, stageCnt; /* temporary variables for counts */ + + pState = &S->pState[0]; + + blkCnt = blockSize >> 2u; + + /* First part of the processing with loop unrolling. Compute 4 outputs at a time. + ** a second loop below computes the remaining 1 to 3 samples. */ + while(blkCnt > 0u) + { + + /* Read two samples from input buffer */ + /* f0(n) = x(n) */ + fcurnt1 = *pSrc++; + fcurnt2 = *pSrc++; + + /* Initialize coeff pointer */ + pk = (pCoeffs); + + /* Initialize state pointer */ + px = pState; + + /* Read g0(n-1) from state */ + gcurnt1 = *px; + + /* Process first sample for first tap */ + /* f1(n) = f0(n) + K1 * g0(n-1) */ + fnext1 = (q31_t) ((gcurnt1 * (*pk)) >> 15u) + fcurnt1; + fnext1 = __SSAT(fnext1, 16); + + /* g1(n) = f0(n) * K1 + g0(n-1) */ + gnext1 = (q31_t) ((fcurnt1 * (*pk)) >> 15u) + gcurnt1; + gnext1 = __SSAT(gnext1, 16); + + /* Process second sample for first tap */ + /* for sample 2 processing */ + fnext2 = (q31_t) ((fcurnt1 * (*pk)) >> 15u) + fcurnt2; + fnext2 = __SSAT(fnext2, 16); + + gnext2 = (q31_t) ((fcurnt2 * (*pk)) >> 15u) + fcurnt1; + gnext2 = __SSAT(gnext2, 16); + + + /* Read next two samples from input buffer */ + /* f0(n+2) = x(n+2) */ + fcurnt3 = *pSrc++; + fcurnt4 = *pSrc++; + + /* Copy only last input samples into the state buffer + which is used for next four samples processing */ + *px++ = (q15_t) fcurnt4; + + /* Process third sample for first tap */ + fnext3 = (q31_t) ((fcurnt2 * (*pk)) >> 15u) + fcurnt3; + fnext3 = __SSAT(fnext3, 16); + gnext3 = (q31_t) ((fcurnt3 * (*pk)) >> 15u) + fcurnt2; + gnext3 = __SSAT(gnext3, 16); + + /* Process fourth sample for first tap */ + fnext4 = (q31_t) ((fcurnt3 * (*pk)) >> 15u) + fcurnt4; + fnext4 = __SSAT(fnext4, 16); + gnext4 = (q31_t) ((fcurnt4 * (*pk++)) >> 15u) + fcurnt3; + gnext4 = __SSAT(gnext4, 16); + + /* Update of f values for next coefficient set processing */ + fcurnt1 = fnext1; + fcurnt2 = fnext2; + fcurnt3 = fnext3; + fcurnt4 = fnext4; + + + /* Loop unrolling. Process 4 taps at a time . */ + stageCnt = (numStages - 1u) >> 2; + + + /* Loop over the number of taps. Unroll by a factor of 4. + ** Repeat until we've computed numStages-3 coefficients. */ + + /* Process 2nd, 3rd, 4th and 5th taps ... here */ + while(stageCnt > 0u) + { + /* Read g1(n-1), g3(n-1) .... from state */ + gcurnt1 = *px; + + /* save g1(n) in state buffer */ + *px++ = (q15_t) gnext4; + + /* Process first sample for 2nd, 6th .. tap */ + /* Sample processing for K2, K6.... */ + /* f1(n) = f0(n) + K1 * g0(n-1) */ + fnext1 = (q31_t) ((gcurnt1 * (*pk)) >> 15u) + fcurnt1; + fnext1 = __SSAT(fnext1, 16); + + + /* Process second sample for 2nd, 6th .. tap */ + /* for sample 2 processing */ + fnext2 = (q31_t) ((gnext1 * (*pk)) >> 15u) + fcurnt2; + fnext2 = __SSAT(fnext2, 16); + /* Process third sample for 2nd, 6th .. tap */ + fnext3 = (q31_t) ((gnext2 * (*pk)) >> 15u) + fcurnt3; + fnext3 = __SSAT(fnext3, 16); + /* Process fourth sample for 2nd, 6th .. tap */ + /* fnext4 = fcurnt4 + (*pk) * gnext3; */ + fnext4 = (q31_t) ((gnext3 * (*pk)) >> 15u) + fcurnt4; + fnext4 = __SSAT(fnext4, 16); + + /* g1(n) = f0(n) * K1 + g0(n-1) */ + /* Calculation of state values for next stage */ + gnext4 = (q31_t) ((fcurnt4 * (*pk)) >> 15u) + gnext3; + gnext4 = __SSAT(gnext4, 16); + gnext3 = (q31_t) ((fcurnt3 * (*pk)) >> 15u) + gnext2; + gnext3 = __SSAT(gnext3, 16); + + gnext2 = (q31_t) ((fcurnt2 * (*pk)) >> 15u) + gnext1; + gnext2 = __SSAT(gnext2, 16); + + gnext1 = (q31_t) ((fcurnt1 * (*pk++)) >> 15u) + gcurnt1; + gnext1 = __SSAT(gnext1, 16); + + + /* Read g2(n-1), g4(n-1) .... from state */ + gcurnt1 = *px; + + /* save g1(n) in state buffer */ + *px++ = (q15_t) gnext4; + + /* Sample processing for K3, K7.... */ + /* Process first sample for 3rd, 7th .. tap */ + /* f3(n) = f2(n) + K3 * g2(n-1) */ + fcurnt1 = (q31_t) ((gcurnt1 * (*pk)) >> 15u) + fnext1; + fcurnt1 = __SSAT(fcurnt1, 16); + + /* Process second sample for 3rd, 7th .. tap */ + fcurnt2 = (q31_t) ((gnext1 * (*pk)) >> 15u) + fnext2; + fcurnt2 = __SSAT(fcurnt2, 16); + + /* Process third sample for 3rd, 7th .. tap */ + fcurnt3 = (q31_t) ((gnext2 * (*pk)) >> 15u) + fnext3; + fcurnt3 = __SSAT(fcurnt3, 16); + + /* Process fourth sample for 3rd, 7th .. tap */ + fcurnt4 = (q31_t) ((gnext3 * (*pk)) >> 15u) + fnext4; + fcurnt4 = __SSAT(fcurnt4, 16); + + /* Calculation of state values for next stage */ + /* g3(n) = f2(n) * K3 + g2(n-1) */ + gnext4 = (q31_t) ((fnext4 * (*pk)) >> 15u) + gnext3; + gnext4 = __SSAT(gnext4, 16); + + gnext3 = (q31_t) ((fnext3 * (*pk)) >> 15u) + gnext2; + gnext3 = __SSAT(gnext3, 16); + + gnext2 = (q31_t) ((fnext2 * (*pk)) >> 15u) + gnext1; + gnext2 = __SSAT(gnext2, 16); + + gnext1 = (q31_t) ((fnext1 * (*pk++)) >> 15u) + gcurnt1; + gnext1 = __SSAT(gnext1, 16); + + /* Read g1(n-1), g3(n-1) .... from state */ + gcurnt1 = *px; + + /* save g1(n) in state buffer */ + *px++ = (q15_t) gnext4; + + /* Sample processing for K4, K8.... */ + /* Process first sample for 4th, 8th .. tap */ + /* f4(n) = f3(n) + K4 * g3(n-1) */ + fnext1 = (q31_t) ((gcurnt1 * (*pk)) >> 15u) + fcurnt1; + fnext1 = __SSAT(fnext1, 16); + + /* Process second sample for 4th, 8th .. tap */ + /* for sample 2 processing */ + fnext2 = (q31_t) ((gnext1 * (*pk)) >> 15u) + fcurnt2; + fnext2 = __SSAT(fnext2, 16); + + /* Process third sample for 4th, 8th .. tap */ + fnext3 = (q31_t) ((gnext2 * (*pk)) >> 15u) + fcurnt3; + fnext3 = __SSAT(fnext3, 16); + + /* Process fourth sample for 4th, 8th .. tap */ + fnext4 = (q31_t) ((gnext3 * (*pk)) >> 15u) + fcurnt4; + fnext4 = __SSAT(fnext4, 16); + + /* g4(n) = f3(n) * K4 + g3(n-1) */ + /* Calculation of state values for next stage */ + gnext4 = (q31_t) ((fcurnt4 * (*pk)) >> 15u) + gnext3; + gnext4 = __SSAT(gnext4, 16); + + gnext3 = (q31_t) ((fcurnt3 * (*pk)) >> 15u) + gnext2; + gnext3 = __SSAT(gnext3, 16); + + gnext2 = (q31_t) ((fcurnt2 * (*pk)) >> 15u) + gnext1; + gnext2 = __SSAT(gnext2, 16); + gnext1 = (q31_t) ((fcurnt1 * (*pk++)) >> 15u) + gcurnt1; + gnext1 = __SSAT(gnext1, 16); + + + /* Read g2(n-1), g4(n-1) .... from state */ + gcurnt1 = *px; + + /* save g4(n) in state buffer */ + *px++ = (q15_t) gnext4; + + /* Sample processing for K5, K9.... */ + /* Process first sample for 5th, 9th .. tap */ + /* f5(n) = f4(n) + K5 * g4(n-1) */ + fcurnt1 = (q31_t) ((gcurnt1 * (*pk)) >> 15u) + fnext1; + fcurnt1 = __SSAT(fcurnt1, 16); + + /* Process second sample for 5th, 9th .. tap */ + fcurnt2 = (q31_t) ((gnext1 * (*pk)) >> 15u) + fnext2; + fcurnt2 = __SSAT(fcurnt2, 16); + + /* Process third sample for 5th, 9th .. tap */ + fcurnt3 = (q31_t) ((gnext2 * (*pk)) >> 15u) + fnext3; + fcurnt3 = __SSAT(fcurnt3, 16); + + /* Process fourth sample for 5th, 9th .. tap */ + fcurnt4 = (q31_t) ((gnext3 * (*pk)) >> 15u) + fnext4; + fcurnt4 = __SSAT(fcurnt4, 16); + + /* Calculation of state values for next stage */ + /* g5(n) = f4(n) * K5 + g4(n-1) */ + gnext4 = (q31_t) ((fnext4 * (*pk)) >> 15u) + gnext3; + gnext4 = __SSAT(gnext4, 16); + gnext3 = (q31_t) ((fnext3 * (*pk)) >> 15u) + gnext2; + gnext3 = __SSAT(gnext3, 16); + gnext2 = (q31_t) ((fnext2 * (*pk)) >> 15u) + gnext1; + gnext2 = __SSAT(gnext2, 16); + gnext1 = (q31_t) ((fnext1 * (*pk++)) >> 15u) + gcurnt1; + gnext1 = __SSAT(gnext1, 16); + + stageCnt--; + } + + /* If the (filter length -1) is not a multiple of 4, compute the remaining filter taps */ + stageCnt = (numStages - 1u) % 0x4u; + + while(stageCnt > 0u) + { + gcurnt1 = *px; + + /* save g value in state buffer */ + *px++ = (q15_t) gnext4; + + /* Process four samples for last three taps here */ + fnext1 = (q31_t) ((gcurnt1 * (*pk)) >> 15u) + fcurnt1; + fnext1 = __SSAT(fnext1, 16); + fnext2 = (q31_t) ((gnext1 * (*pk)) >> 15u) + fcurnt2; + fnext2 = __SSAT(fnext2, 16); + + fnext3 = (q31_t) ((gnext2 * (*pk)) >> 15u) + fcurnt3; + fnext3 = __SSAT(fnext3, 16); + + fnext4 = (q31_t) ((gnext3 * (*pk)) >> 15u) + fcurnt4; + fnext4 = __SSAT(fnext4, 16); + + /* g1(n) = f0(n) * K1 + g0(n-1) */ + gnext4 = (q31_t) ((fcurnt4 * (*pk)) >> 15u) + gnext3; + gnext4 = __SSAT(gnext4, 16); + gnext3 = (q31_t) ((fcurnt3 * (*pk)) >> 15u) + gnext2; + gnext3 = __SSAT(gnext3, 16); + gnext2 = (q31_t) ((fcurnt2 * (*pk)) >> 15u) + gnext1; + gnext2 = __SSAT(gnext2, 16); + gnext1 = (q31_t) ((fcurnt1 * (*pk++)) >> 15u) + gcurnt1; + gnext1 = __SSAT(gnext1, 16); + + /* Update of f values for next coefficient set processing */ + fcurnt1 = fnext1; + fcurnt2 = fnext2; + fcurnt3 = fnext3; + fcurnt4 = fnext4; + + stageCnt--; + + } + + /* The results in the 4 accumulators, store in the destination buffer. */ + /* y(n) = fN(n) */ + +#ifndef ARM_MATH_BIG_ENDIAN + + *__SIMD32(pDst)++ = __PKHBT(fcurnt1, fcurnt2, 16); + *__SIMD32(pDst)++ = __PKHBT(fcurnt3, fcurnt4, 16); + +#else + + *__SIMD32(pDst)++ = __PKHBT(fcurnt2, fcurnt1, 16); + *__SIMD32(pDst)++ = __PKHBT(fcurnt4, fcurnt3, 16); + +#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ + + blkCnt--; + } + + /* If the blockSize is not a multiple of 4, compute any remaining output samples here. + ** No loop unrolling is used. */ + blkCnt = blockSize % 0x4u; + + while(blkCnt > 0u) + { + /* f0(n) = x(n) */ + fcurnt1 = *pSrc++; + + /* Initialize coeff pointer */ + pk = (pCoeffs); + + /* Initialize state pointer */ + px = pState; + + /* read g2(n) from state buffer */ + gcurnt1 = *px; + + /* for sample 1 processing */ + /* f1(n) = f0(n) + K1 * g0(n-1) */ + fnext1 = (((q31_t) gcurnt1 * (*pk)) >> 15u) + fcurnt1; + fnext1 = __SSAT(fnext1, 16); + + + /* g1(n) = f0(n) * K1 + g0(n-1) */ + gnext1 = (((q31_t) fcurnt1 * (*pk++)) >> 15u) + gcurnt1; + gnext1 = __SSAT(gnext1, 16); + + /* save g1(n) in state buffer */ + *px++ = (q15_t) fcurnt1; + + /* f1(n) is saved in fcurnt1 + for next stage processing */ + fcurnt1 = fnext1; + + stageCnt = (numStages - 1u); + + /* stage loop */ + while(stageCnt > 0u) + { + /* read g2(n) from state buffer */ + gcurnt1 = *px; + + /* save g1(n) in state buffer */ + *px++ = (q15_t) gnext1; + + /* Sample processing for K2, K3.... */ + /* f2(n) = f1(n) + K2 * g1(n-1) */ + fnext1 = (((q31_t) gcurnt1 * (*pk)) >> 15u) + fcurnt1; + fnext1 = __SSAT(fnext1, 16); + + /* g2(n) = f1(n) * K2 + g1(n-1) */ + gnext1 = (((q31_t) fcurnt1 * (*pk++)) >> 15u) + gcurnt1; + gnext1 = __SSAT(gnext1, 16); + + + /* f1(n) is saved in fcurnt1 + for next stage processing */ + fcurnt1 = fnext1; + + stageCnt--; + + } + + /* y(n) = fN(n) */ + *pDst++ = __SSAT(fcurnt1, 16); + + + blkCnt--; + + } + +#else + + /* Run the below code for Cortex-M0 */ + + q31_t fcurnt, fnext, gcurnt, 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) */ + fcurnt = *pSrc++; + + /* Initialize coeff pointer */ + pk = (pCoeffs); + + /* Initialize state pointer */ + px = pState; + + /* read g0(n-1) from state buffer */ + gcurnt = *px; + + /* for sample 1 processing */ + /* f1(n) = f0(n) + K1 * g0(n-1) */ + fnext = ((gcurnt * (*pk)) >> 15u) + fcurnt; + fnext = __SSAT(fnext, 16); + + + /* g1(n) = f0(n) * K1 + g0(n-1) */ + gnext = ((fcurnt * (*pk++)) >> 15u) + gcurnt; + gnext = __SSAT(gnext, 16); + + /* save f0(n) in state buffer */ + *px++ = (q15_t) fcurnt; + + /* f1(n) is saved in fcurnt + for next stage processing */ + fcurnt = fnext; + + stageCnt = (numStages - 1u); + + /* stage loop */ + while(stageCnt > 0u) + { + /* read g1(n-1) from state buffer */ + gcurnt = *px; + + /* save g0(n-1) in state buffer */ + *px++ = (q15_t) gnext; + + /* Sample processing for K2, K3.... */ + /* f2(n) = f1(n) + K2 * g1(n-1) */ + fnext = ((gcurnt * (*pk)) >> 15u) + fcurnt; + fnext = __SSAT(fnext, 16); + + /* g2(n) = f1(n) * K2 + g1(n-1) */ + gnext = ((fcurnt * (*pk++)) >> 15u) + gcurnt; + gnext = __SSAT(gnext, 16); + + + /* f1(n) is saved in fcurnt + for next stage processing */ + fcurnt = fnext; + + stageCnt--; + + } + + /* y(n) = fN(n) */ + *pDst++ = __SSAT(fcurnt, 16); + + + blkCnt--; + + } + +#endif /* #ifndef ARM_MATH_CM0_FAMILY */ + +} + +/** + * @} end of FIR_Lattice group + */ |