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Diffstat (limited to 'DSP_Lib/Source/FilteringFunctions/arm_iir_lattice_q31.c')
-rw-r--r-- | DSP_Lib/Source/FilteringFunctions/arm_iir_lattice_q31.c | 350 |
1 files changed, 0 insertions, 350 deletions
diff --git a/DSP_Lib/Source/FilteringFunctions/arm_iir_lattice_q31.c b/DSP_Lib/Source/FilteringFunctions/arm_iir_lattice_q31.c deleted file mode 100644 index 347c857..0000000 --- a/DSP_Lib/Source/FilteringFunctions/arm_iir_lattice_q31.c +++ /dev/null @@ -1,350 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2014 ARM Limited. All rights reserved. -* -* $Date: 19. March 2015 -* $Revision: V.1.4.5 -* -* Project: CMSIS DSP Library -* Title: arm_iir_lattice_q31.c -* -* Description: Q31 IIR 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 IIR_Lattice - * @{ - */ - -/** - * @brief Processing function for the Q31 IIR lattice filter. - * @param[in] *S points to an instance of the Q31 IIR 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> - * \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 2*log2(numStages) bits. - * After all multiply-accumulates are performed, the 2.62 accumulator is saturated to 1.32 format and then truncated to 1.31 format. - */ - -void arm_iir_lattice_q31( - const arm_iir_lattice_instance_q31 * S, - q31_t * pSrc, - q31_t * pDst, - uint32_t blockSize) -{ - q31_t fcurr, fnext = 0, gcurr = 0, gnext; /* Temporary variables for lattice stages */ - q63_t acc; /* Accumlator */ - uint32_t blkCnt, tapCnt; /* Temporary variables for counts */ - q31_t *px1, *px2, *pk, *pv; /* Temporary pointers for state and coef */ - uint32_t numStages = S->numStages; /* number of stages */ - q31_t *pState; /* State pointer */ - q31_t *pStateCurnt; /* State current pointer */ - - blkCnt = blockSize; - - pState = &S->pState[0]; - - -#ifndef ARM_MATH_CM0_FAMILY - - /* Run the below code for Cortex-M4 and Cortex-M3 */ - - /* Sample processing */ - while(blkCnt > 0u) - { - /* Read Sample from input buffer */ - /* fN(n) = x(n) */ - fcurr = *pSrc++; - - /* Initialize state read pointer */ - px1 = pState; - /* Initialize state write pointer */ - px2 = pState; - /* Set accumulator to zero */ - acc = 0; - /* Initialize Ladder coeff pointer */ - pv = &S->pvCoeffs[0]; - /* Initialize Reflection coeff pointer */ - pk = &S->pkCoeffs[0]; - - - /* Process sample for first tap */ - gcurr = *px1++; - /* fN-1(n) = fN(n) - kN * gN-1(n-1) */ - fnext = __QSUB(fcurr, (q31_t) (((q63_t) gcurr * (*pk)) >> 31)); - /* gN(n) = kN * fN-1(n) + gN-1(n-1) */ - gnext = __QADD(gcurr, (q31_t) (((q63_t) fnext * (*pk++)) >> 31)); - /* write gN-1(n-1) into state for next sample processing */ - *px2++ = gnext; - /* y(n) += gN(n) * vN */ - acc += ((q63_t) gnext * *pv++); - - /* Update f values for next coefficient processing */ - fcurr = fnext; - - /* Loop unrolling. Process 4 taps at a time. */ - tapCnt = (numStages - 1u) >> 2; - - while(tapCnt > 0u) - { - - /* Process sample for 2nd, 6th .. taps */ - /* Read gN-2(n-1) from state buffer */ - gcurr = *px1++; - /* fN-2(n) = fN-1(n) - kN-1 * gN-2(n-1) */ - fnext = __QSUB(fcurr, (q31_t) (((q63_t) gcurr * (*pk)) >> 31)); - /* gN-1(n) = kN-1 * fN-2(n) + gN-2(n-1) */ - gnext = __QADD(gcurr, (q31_t) (((q63_t) fnext * (*pk++)) >> 31)); - /* y(n) += gN-1(n) * vN-1 */ - /* process for gN-5(n) * vN-5, gN-9(n) * vN-9 ... */ - acc += ((q63_t) gnext * *pv++); - /* write gN-1(n) into state for next sample processing */ - *px2++ = gnext; - - /* Process sample for 3nd, 7th ...taps */ - /* Read gN-3(n-1) from state buffer */ - gcurr = *px1++; - /* Process sample for 3rd, 7th .. taps */ - /* fN-3(n) = fN-2(n) - kN-2 * gN-3(n-1) */ - fcurr = __QSUB(fnext, (q31_t) (((q63_t) gcurr * (*pk)) >> 31)); - /* gN-2(n) = kN-2 * fN-3(n) + gN-3(n-1) */ - gnext = __QADD(gcurr, (q31_t) (((q63_t) fcurr * (*pk++)) >> 31)); - /* y(n) += gN-2(n) * vN-2 */ - /* process for gN-6(n) * vN-6, gN-10(n) * vN-10 ... */ - acc += ((q63_t) gnext * *pv++); - /* write gN-2(n) into state for next sample processing */ - *px2++ = gnext; - - - /* Process sample for 4th, 8th ...taps */ - /* Read gN-4(n-1) from state buffer */ - gcurr = *px1++; - /* Process sample for 4th, 8th .. taps */ - /* fN-4(n) = fN-3(n) - kN-3 * gN-4(n-1) */ - fnext = __QSUB(fcurr, (q31_t) (((q63_t) gcurr * (*pk)) >> 31)); - /* gN-3(n) = kN-3 * fN-4(n) + gN-4(n-1) */ - gnext = __QADD(gcurr, (q31_t) (((q63_t) fnext * (*pk++)) >> 31)); - /* y(n) += gN-3(n) * vN-3 */ - /* process for gN-7(n) * vN-7, gN-11(n) * vN-11 ... */ - acc += ((q63_t) gnext * *pv++); - /* write gN-3(n) into state for next sample processing */ - *px2++ = gnext; - - - /* Process sample for 5th, 9th ...taps */ - /* Read gN-5(n-1) from state buffer */ - gcurr = *px1++; - /* Process sample for 5th, 9th .. taps */ - /* fN-5(n) = fN-4(n) - kN-4 * gN-1(n-1) */ - fcurr = __QSUB(fnext, (q31_t) (((q63_t) gcurr * (*pk)) >> 31)); - /* gN-4(n) = kN-4 * fN-5(n) + gN-5(n-1) */ - gnext = __QADD(gcurr, (q31_t) (((q63_t) fcurr * (*pk++)) >> 31)); - /* y(n) += gN-4(n) * vN-4 */ - /* process for gN-8(n) * vN-8, gN-12(n) * vN-12 ... */ - acc += ((q63_t) gnext * *pv++); - /* write gN-4(n) into state for next sample processing */ - *px2++ = gnext; - - tapCnt--; - - } - - fnext = fcurr; - - /* If the filter length is not a multiple of 4, compute the remaining filter taps */ - tapCnt = (numStages - 1u) % 0x4u; - - while(tapCnt > 0u) - { - gcurr = *px1++; - /* Process sample for last taps */ - fnext = __QSUB(fcurr, (q31_t) (((q63_t) gcurr * (*pk)) >> 31)); - gnext = __QADD(gcurr, (q31_t) (((q63_t) fnext * (*pk++)) >> 31)); - /* Output samples for last taps */ - acc += ((q63_t) gnext * *pv++); - *px2++ = gnext; - fcurr = fnext; - - tapCnt--; - - } - - /* y(n) += g0(n) * v0 */ - acc += (q63_t) fnext *( - *pv++); - - *px2++ = fnext; - - /* write out into pDst */ - *pDst++ = (q31_t) (acc >> 31u); - - /* Advance the state pointer by 4 to process the next group of 4 samples */ - pState = pState + 1u; - blkCnt--; - - } - - /* Processing is complete. Now copy last S->numStages samples to start of the buffer - for the preperation of next frame process */ - - /* Points to the start of the state buffer */ - pStateCurnt = &S->pState[0]; - pState = &S->pState[blockSize]; - - tapCnt = numStages >> 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 = (numStages) % 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 */ - /* Sample processing */ - while(blkCnt > 0u) - { - /* Read Sample from input buffer */ - /* fN(n) = x(n) */ - fcurr = *pSrc++; - - /* Initialize state read pointer */ - px1 = pState; - /* Initialize state write pointer */ - px2 = pState; - /* Set accumulator to zero */ - acc = 0; - /* Initialize Ladder coeff pointer */ - pv = &S->pvCoeffs[0]; - /* Initialize Reflection coeff pointer */ - pk = &S->pkCoeffs[0]; - - tapCnt = numStages; - - while(tapCnt > 0u) - { - gcurr = *px1++; - /* Process sample */ - /* fN-1(n) = fN(n) - kN * gN-1(n-1) */ - fnext = - clip_q63_to_q31(((q63_t) fcurr - - ((q31_t) (((q63_t) gcurr * (*pk)) >> 31)))); - /* gN(n) = kN * fN-1(n) + gN-1(n-1) */ - gnext = - clip_q63_to_q31(((q63_t) gcurr + - ((q31_t) (((q63_t) fnext * (*pk++)) >> 31)))); - /* Output samples */ - /* y(n) += gN(n) * vN */ - acc += ((q63_t) gnext * *pv++); - /* write gN-1(n-1) into state for next sample processing */ - *px2++ = gnext; - /* Update f values for next coefficient processing */ - fcurr = fnext; - - tapCnt--; - } - - /* y(n) += g0(n) * v0 */ - acc += (q63_t) fnext *( - *pv++); - - *px2++ = fnext; - - /* write out into pDst */ - *pDst++ = (q31_t) (acc >> 31u); - - /* Advance the state pointer by 1 to process the next group of samples */ - pState = pState + 1u; - blkCnt--; - - } - - /* Processing is complete. Now copy last S->numStages samples to start of the buffer - for the preperation of next frame process */ - - /* Points to the start of the state buffer */ - pStateCurnt = &S->pState[0]; - pState = &S->pState[blockSize]; - - tapCnt = numStages; - - /* Copy the remaining q31_t data */ - while(tapCnt > 0u) - { - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - tapCnt--; - } - -#endif /* #ifndef ARM_MATH_CM0_FAMILY */ - -} - - - - -/** - * @} end of IIR_Lattice group - */ |