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Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_q15.c')
-rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_q15.c | 691 |
1 files changed, 0 insertions, 691 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_q15.c b/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_q15.c deleted file mode 100644 index 840507fb72..0000000000 --- a/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_q15.c +++ /dev/null @@ -1,691 +0,0 @@ -/* ---------------------------------------------------------------------- -* Copyright (C) 2010-2013 ARM Limited. All rights reserved. -* -* $Date: 17. January 2013 -* $Revision: V1.4.1 -* -* Project: CMSIS DSP Library -* Title: arm_fir_q15.c -* -* Description: Q15 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" - -/** - * @ingroup groupFilters - */ - -/** - * @addtogroup FIR - * @{ - */ - -/** - * @brief Processing function for the Q15 FIR filter. - * @param[in] *S points to an instance of the Q15 FIR 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 per call. - * @return none. - * - * - * \par Restrictions - * If the silicon does not support unaligned memory access enable the macro UNALIGNED_SUPPORT_DISABLE - * In this case input, output, state buffers should be aligned by 32-bit - * - * <b>Scaling and Overflow Behavior:</b> - * \par - * The function is implemented using a 64-bit internal accumulator. - * Both coefficients and state variables are represented in 1.15 format and multiplications yield a 2.30 result. - * The 2.30 intermediate results are accumulated in a 64-bit accumulator in 34.30 format. - * There is no risk of internal overflow with this approach and the full precision of intermediate multiplications is preserved. - * After all additions have been performed, the accumulator is truncated to 34.15 format by discarding low 15 bits. - * Lastly, the accumulator is saturated to yield a result in 1.15 format. - * - * \par - * Refer to the function <code>arm_fir_fast_q15()</code> for a faster but less precise implementation of this function. - */ - -#ifndef ARM_MATH_CM0_FAMILY - -/* Run the below code for Cortex-M4 and Cortex-M3 */ - -#ifndef UNALIGNED_SUPPORT_DISABLE - - -void arm_fir_q15( - const arm_fir_instance_q15 * S, - q15_t * pSrc, - q15_t * pDst, - uint32_t blockSize) -{ - q15_t *pState = S->pState; /* State pointer */ - q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ - q15_t *pStateCurnt; /* Points to the current sample of the state */ - q15_t *px1; /* Temporary q15 pointer for state buffer */ - q15_t *pb; /* Temporary pointer for coefficient buffer */ - q31_t x0, x1, x2, x3, c0; /* Temporary variables to hold SIMD state and coefficient values */ - q63_t acc0, acc1, acc2, acc3; /* Accumulators */ - uint32_t numTaps = S->numTaps; /* Number of taps in the filter */ - uint32_t tapCnt, blkCnt; /* Loop counters */ - - - /* S->pState points to state array 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)]); - - /* Apply loop unrolling and compute 4 output values simultaneously. - * The variables acc0 ... acc3 hold output values that are being computed: - * - * acc0 = b[numTaps-1] * x[n-numTaps-1] + b[numTaps-2] * x[n-numTaps-2] + b[numTaps-3] * x[n-numTaps-3] +...+ b[0] * x[0] - * acc1 = b[numTaps-1] * x[n-numTaps] + b[numTaps-2] * x[n-numTaps-1] + b[numTaps-3] * x[n-numTaps-2] +...+ b[0] * x[1] - * acc2 = b[numTaps-1] * x[n-numTaps+1] + b[numTaps-2] * x[n-numTaps] + b[numTaps-3] * x[n-numTaps-1] +...+ b[0] * x[2] - * acc3 = b[numTaps-1] * x[n-numTaps+2] + b[numTaps-2] * x[n-numTaps+1] + b[numTaps-3] * x[n-numTaps] +...+ b[0] * x[3] - */ - - blkCnt = blockSize >> 2; - - /* 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) - { - /* Copy four new input samples into the state buffer. - ** Use 32-bit SIMD to move the 16-bit data. Only requires two copies. */ - *__SIMD32(pStateCurnt)++ = *__SIMD32(pSrc)++; - *__SIMD32(pStateCurnt)++ = *__SIMD32(pSrc)++; - - /* Set all accumulators to zero */ - acc0 = 0; - acc1 = 0; - acc2 = 0; - acc3 = 0; - - /* Initialize state pointer of type q15 */ - px1 = pState; - - /* Initialize coeff pointer of type q31 */ - pb = pCoeffs; - - /* Read the first two samples from the state buffer: x[n-N], x[n-N-1] */ - x0 = _SIMD32_OFFSET(px1); - - /* Read the third and forth samples from the state buffer: x[n-N-1], x[n-N-2] */ - x1 = _SIMD32_OFFSET(px1 + 1u); - - px1 += 2u; - - /* Loop over the number of taps. Unroll by a factor of 4. - ** Repeat until we've computed numTaps-4 coefficients. */ - tapCnt = numTaps >> 2; - - while(tapCnt > 0u) - { - /* Read the first two coefficients using SIMD: b[N] and b[N-1] coefficients */ - c0 = *__SIMD32(pb)++; - - /* acc0 += b[N] * x[n-N] + b[N-1] * x[n-N-1] */ - acc0 = __SMLALD(x0, c0, acc0); - - /* acc1 += b[N] * x[n-N-1] + b[N-1] * x[n-N-2] */ - acc1 = __SMLALD(x1, c0, acc1); - - /* Read state x[n-N-2], x[n-N-3] */ - x2 = _SIMD32_OFFSET(px1); - - /* Read state x[n-N-3], x[n-N-4] */ - x3 = _SIMD32_OFFSET(px1 + 1u); - - /* acc2 += b[N] * x[n-N-2] + b[N-1] * x[n-N-3] */ - acc2 = __SMLALD(x2, c0, acc2); - - /* acc3 += b[N] * x[n-N-3] + b[N-1] * x[n-N-4] */ - acc3 = __SMLALD(x3, c0, acc3); - - /* Read coefficients b[N-2], b[N-3] */ - c0 = *__SIMD32(pb)++; - - /* acc0 += b[N-2] * x[n-N-2] + b[N-3] * x[n-N-3] */ - acc0 = __SMLALD(x2, c0, acc0); - - /* acc1 += b[N-2] * x[n-N-3] + b[N-3] * x[n-N-4] */ - acc1 = __SMLALD(x3, c0, acc1); - - /* Read state x[n-N-4], x[n-N-5] */ - x0 = _SIMD32_OFFSET(px1 + 2u); - - /* Read state x[n-N-5], x[n-N-6] */ - x1 = _SIMD32_OFFSET(px1 + 3u); - - /* acc2 += b[N-2] * x[n-N-4] + b[N-3] * x[n-N-5] */ - acc2 = __SMLALD(x0, c0, acc2); - - /* acc3 += b[N-2] * x[n-N-5] + b[N-3] * x[n-N-6] */ - acc3 = __SMLALD(x1, c0, acc3); - - px1 += 4u; - - tapCnt--; - - } - - - /* If the filter length is not a multiple of 4, compute the remaining filter taps. - ** This is always be 2 taps since the filter length is even. */ - if((numTaps & 0x3u) != 0u) - { - /* Read 2 coefficients */ - c0 = *__SIMD32(pb)++; - - /* Fetch 4 state variables */ - x2 = _SIMD32_OFFSET(px1); - - x3 = _SIMD32_OFFSET(px1 + 1u); - - /* Perform the multiply-accumulates */ - acc0 = __SMLALD(x0, c0, acc0); - - px1 += 2u; - - acc1 = __SMLALD(x1, c0, acc1); - acc2 = __SMLALD(x2, c0, acc2); - acc3 = __SMLALD(x3, c0, acc3); - } - - /* The results in the 4 accumulators are in 2.30 format. Convert to 1.15 with saturation. - ** Then store the 4 outputs in the destination buffer. */ - -#ifndef ARM_MATH_BIG_ENDIAN - - *__SIMD32(pDst)++ = - __PKHBT(__SSAT((acc0 >> 15), 16), __SSAT((acc1 >> 15), 16), 16); - *__SIMD32(pDst)++ = - __PKHBT(__SSAT((acc2 >> 15), 16), __SSAT((acc3 >> 15), 16), 16); - -#else - - *__SIMD32(pDst)++ = - __PKHBT(__SSAT((acc1 >> 15), 16), __SSAT((acc0 >> 15), 16), 16); - *__SIMD32(pDst)++ = - __PKHBT(__SSAT((acc3 >> 15), 16), __SSAT((acc2 >> 15), 16), 16); - -#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ - - - - /* Advance the state pointer by 4 to process the next group of 4 samples */ - pState = pState + 4; - - /* Decrement the loop counter */ - 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) - { - /* Copy two samples into state buffer */ - *pStateCurnt++ = *pSrc++; - - /* Set the accumulator to zero */ - acc0 = 0; - - /* Initialize state pointer of type q15 */ - px1 = pState; - - /* Initialize coeff pointer of type q31 */ - pb = pCoeffs; - - tapCnt = numTaps >> 1; - - do - { - - c0 = *__SIMD32(pb)++; - x0 = *__SIMD32(px1)++; - - acc0 = __SMLALD(x0, c0, acc0); - tapCnt--; - } - while(tapCnt > 0u); - - /* The result is in 2.30 format. Convert to 1.15 with saturation. - ** Then store the output in the destination buffer. */ - *pDst++ = (q15_t) (__SSAT((acc0 >> 15), 16)); - - /* Advance state pointer by 1 for the next sample */ - pState = pState + 1; - - /* Decrement the loop counter */ - blkCnt--; - } - - /* 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 state buffer */ - pStateCurnt = S->pState; - - /* Calculation of count for copying integer writes */ - tapCnt = (numTaps - 1u) >> 2; - - while(tapCnt > 0u) - { - - /* Copy state values to start of state buffer */ - *__SIMD32(pStateCurnt)++ = *__SIMD32(pState)++; - *__SIMD32(pStateCurnt)++ = *__SIMD32(pState)++; - - tapCnt--; - - } - - /* Calculation of count for remaining q15_t data */ - tapCnt = (numTaps - 1u) % 0x4u; - - /* copy remaining data */ - while(tapCnt > 0u) - { - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - tapCnt--; - } -} - -#else /* UNALIGNED_SUPPORT_DISABLE */ - -void arm_fir_q15( - const arm_fir_instance_q15 * S, - q15_t * pSrc, - q15_t * pDst, - uint32_t blockSize) -{ - q15_t *pState = S->pState; /* State pointer */ - q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ - q15_t *pStateCurnt; /* Points to the current sample of the state */ - q63_t acc0, acc1, acc2, acc3; /* Accumulators */ - q15_t *pb; /* Temporary pointer for coefficient buffer */ - q15_t *px; /* Temporary q31 pointer for SIMD state buffer accesses */ - q31_t x0, x1, x2, c0; /* Temporary variables to hold SIMD state and coefficient values */ - uint32_t numTaps = S->numTaps; /* Number of taps in the filter */ - uint32_t tapCnt, blkCnt; /* Loop counters */ - - - /* S->pState points to state array 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)]); - - /* Apply loop unrolling and compute 4 output values simultaneously. - * The variables acc0 ... acc3 hold output values that are being computed: - * - * acc0 = b[numTaps-1] * x[n-numTaps-1] + b[numTaps-2] * x[n-numTaps-2] + b[numTaps-3] * x[n-numTaps-3] +...+ b[0] * x[0] - * acc1 = b[numTaps-1] * x[n-numTaps] + b[numTaps-2] * x[n-numTaps-1] + b[numTaps-3] * x[n-numTaps-2] +...+ b[0] * x[1] - * acc2 = b[numTaps-1] * x[n-numTaps+1] + b[numTaps-2] * x[n-numTaps] + b[numTaps-3] * x[n-numTaps-1] +...+ b[0] * x[2] - * acc3 = b[numTaps-1] * x[n-numTaps+2] + b[numTaps-2] * x[n-numTaps+1] + b[numTaps-3] * x[n-numTaps] +...+ b[0] * x[3] - */ - - blkCnt = blockSize >> 2; - - /* 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) - { - /* Copy four new input samples into the state buffer. - ** Use 32-bit SIMD to move the 16-bit data. Only requires two copies. */ - *pStateCurnt++ = *pSrc++; - *pStateCurnt++ = *pSrc++; - *pStateCurnt++ = *pSrc++; - *pStateCurnt++ = *pSrc++; - - - /* Set all accumulators to zero */ - acc0 = 0; - acc1 = 0; - acc2 = 0; - acc3 = 0; - - /* Typecast q15_t pointer to q31_t pointer for state reading in q31_t */ - px = pState; - - /* Typecast q15_t pointer to q31_t pointer for coefficient reading in q31_t */ - pb = pCoeffs; - - /* Read the first two samples from the state buffer: x[n-N], x[n-N-1] */ - x0 = *__SIMD32(px)++; - - /* Read the third and forth samples from the state buffer: x[n-N-2], x[n-N-3] */ - x2 = *__SIMD32(px)++; - - /* Loop over the number of taps. Unroll by a factor of 4. - ** Repeat until we've computed numTaps-(numTaps%4) coefficients. */ - tapCnt = numTaps >> 2; - - while(tapCnt > 0) - { - /* Read the first two coefficients using SIMD: b[N] and b[N-1] coefficients */ - c0 = *__SIMD32(pb)++; - - /* acc0 += b[N] * x[n-N] + b[N-1] * x[n-N-1] */ - acc0 = __SMLALD(x0, c0, acc0); - - /* acc2 += b[N] * x[n-N-2] + b[N-1] * x[n-N-3] */ - acc2 = __SMLALD(x2, c0, acc2); - - /* pack x[n-N-1] and x[n-N-2] */ -#ifndef ARM_MATH_BIG_ENDIAN - x1 = __PKHBT(x2, x0, 0); -#else - x1 = __PKHBT(x0, x2, 0); -#endif - - /* Read state x[n-N-4], x[n-N-5] */ - x0 = _SIMD32_OFFSET(px); - - /* acc1 += b[N] * x[n-N-1] + b[N-1] * x[n-N-2] */ - acc1 = __SMLALDX(x1, c0, acc1); - - /* pack x[n-N-3] and x[n-N-4] */ -#ifndef ARM_MATH_BIG_ENDIAN - x1 = __PKHBT(x0, x2, 0); -#else - x1 = __PKHBT(x2, x0, 0); -#endif - - /* acc3 += b[N] * x[n-N-3] + b[N-1] * x[n-N-4] */ - acc3 = __SMLALDX(x1, c0, acc3); - - /* Read coefficients b[N-2], b[N-3] */ - c0 = *__SIMD32(pb)++; - - /* acc0 += b[N-2] * x[n-N-2] + b[N-3] * x[n-N-3] */ - acc0 = __SMLALD(x2, c0, acc0); - - /* Read state x[n-N-6], x[n-N-7] with offset */ - x2 = _SIMD32_OFFSET(px + 2u); - - /* acc2 += b[N-2] * x[n-N-4] + b[N-3] * x[n-N-5] */ - acc2 = __SMLALD(x0, c0, acc2); - - /* acc1 += b[N-2] * x[n-N-3] + b[N-3] * x[n-N-4] */ - acc1 = __SMLALDX(x1, c0, acc1); - - /* pack x[n-N-5] and x[n-N-6] */ -#ifndef ARM_MATH_BIG_ENDIAN - x1 = __PKHBT(x2, x0, 0); -#else - x1 = __PKHBT(x0, x2, 0); -#endif - - /* acc3 += b[N-2] * x[n-N-5] + b[N-3] * x[n-N-6] */ - acc3 = __SMLALDX(x1, c0, acc3); - - /* Update state pointer for next state reading */ - px += 4u; - - /* Decrement tap count */ - tapCnt--; - - } - - /* If the filter length is not a multiple of 4, compute the remaining filter taps. - ** This is always be 2 taps since the filter length is even. */ - if((numTaps & 0x3u) != 0u) - { - - /* Read last two coefficients */ - c0 = *__SIMD32(pb)++; - - /* Perform the multiply-accumulates */ - acc0 = __SMLALD(x0, c0, acc0); - acc2 = __SMLALD(x2, c0, acc2); - - /* pack state variables */ -#ifndef ARM_MATH_BIG_ENDIAN - x1 = __PKHBT(x2, x0, 0); -#else - x1 = __PKHBT(x0, x2, 0); -#endif - - /* Read last state variables */ - x0 = *__SIMD32(px); - - /* Perform the multiply-accumulates */ - acc1 = __SMLALDX(x1, c0, acc1); - - /* pack state variables */ -#ifndef ARM_MATH_BIG_ENDIAN - x1 = __PKHBT(x0, x2, 0); -#else - x1 = __PKHBT(x2, x0, 0); -#endif - - /* Perform the multiply-accumulates */ - acc3 = __SMLALDX(x1, c0, acc3); - } - - /* The results in the 4 accumulators are in 2.30 format. Convert to 1.15 with saturation. - ** Then store the 4 outputs in the destination buffer. */ - -#ifndef ARM_MATH_BIG_ENDIAN - - *__SIMD32(pDst)++ = - __PKHBT(__SSAT((acc0 >> 15), 16), __SSAT((acc1 >> 15), 16), 16); - - *__SIMD32(pDst)++ = - __PKHBT(__SSAT((acc2 >> 15), 16), __SSAT((acc3 >> 15), 16), 16); - -#else - - *__SIMD32(pDst)++ = - __PKHBT(__SSAT((acc1 >> 15), 16), __SSAT((acc0 >> 15), 16), 16); - - *__SIMD32(pDst)++ = - __PKHBT(__SSAT((acc3 >> 15), 16), __SSAT((acc2 >> 15), 16), 16); - -#endif /* #ifndef ARM_MATH_BIG_ENDIAN */ - - /* Advance the state pointer by 4 to process the next group of 4 samples */ - pState = pState + 4; - - /* Decrement the loop counter */ - 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) - { - /* Copy two samples into state buffer */ - *pStateCurnt++ = *pSrc++; - - /* Set the accumulator to zero */ - acc0 = 0; - - /* Use SIMD to hold states and coefficients */ - px = pState; - pb = pCoeffs; - - tapCnt = numTaps >> 1u; - - do - { - acc0 += (q31_t) * px++ * *pb++; - acc0 += (q31_t) * px++ * *pb++; - tapCnt--; - } - while(tapCnt > 0u); - - /* The result is in 2.30 format. Convert to 1.15 with saturation. - ** Then store the output in the destination buffer. */ - *pDst++ = (q15_t) (__SSAT((acc0 >> 15), 16)); - - /* Advance state pointer by 1 for the next sample */ - pState = pState + 1u; - - /* Decrement the loop counter */ - blkCnt--; - } - - /* 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 state buffer */ - pStateCurnt = S->pState; - - /* Calculation of count for copying integer writes */ - tapCnt = (numTaps - 1u) >> 2; - - while(tapCnt > 0u) - { - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - - tapCnt--; - - } - - /* Calculation of count for remaining q15_t data */ - tapCnt = (numTaps - 1u) % 0x4u; - - /* copy remaining data */ - while(tapCnt > 0u) - { - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - tapCnt--; - } -} - - -#endif /* #ifndef UNALIGNED_SUPPORT_DISABLE */ - -#else /* ARM_MATH_CM0_FAMILY */ - - -/* Run the below code for Cortex-M0 */ - -void arm_fir_q15( - const arm_fir_instance_q15 * S, - q15_t * pSrc, - q15_t * pDst, - uint32_t blockSize) -{ - q15_t *pState = S->pState; /* State pointer */ - q15_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ - q15_t *pStateCurnt; /* Points to the current sample of the state */ - - - - q15_t *px; /* Temporary pointer for state buffer */ - q15_t *pb; /* Temporary pointer for coefficient buffer */ - q63_t acc; /* Accumulator */ - uint32_t numTaps = S->numTaps; /* Number of nTaps in the filter */ - uint32_t tapCnt, blkCnt; /* Loop counters */ - - /* S->pState buffer contains previous frame (numTaps - 1) samples */ - /* pStateCurnt points to the location where the new input data should be written */ - pStateCurnt = &(S->pState[(numTaps - 1u)]); - - /* Initialize blkCnt with blockSize */ - blkCnt = blockSize; - - while(blkCnt > 0u) - { - /* Copy one sample at a time into state buffer */ - *pStateCurnt++ = *pSrc++; - - /* Set the accumulator to zero */ - acc = 0; - - /* Initialize state pointer */ - px = pState; - - /* Initialize Coefficient pointer */ - pb = pCoeffs; - - tapCnt = numTaps; - - /* Perform the multiply-accumulates */ - do - { - /* acc = b[numTaps-1] * x[n-numTaps-1] + b[numTaps-2] * x[n-numTaps-2] + b[numTaps-3] * x[n-numTaps-3] +...+ b[0] * x[0] */ - acc += (q31_t) * px++ * *pb++; - tapCnt--; - } while(tapCnt > 0u); - - /* The result is in 2.30 format. Convert to 1.15 - ** Then store the output in the destination buffer. */ - *pDst++ = (q15_t) __SSAT((acc >> 15u), 16); - - /* Advance state pointer by 1 for the next sample */ - pState = pState + 1; - - /* Decrement the samples loop counter */ - blkCnt--; - } - - /* 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 state buffer */ - pStateCurnt = S->pState; - - /* Copy numTaps number of values */ - tapCnt = (numTaps - 1u); - - /* copy data */ - while(tapCnt > 0u) - { - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - tapCnt--; - } - -} - -#endif /* #ifndef ARM_MATH_CM0_FAMILY */ - - - - -/** - * @} end of FIR group - */ |