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Diffstat (limited to 'DSP_Lib/Source/FilteringFunctions/arm_fir_q7.c')
-rw-r--r-- | DSP_Lib/Source/FilteringFunctions/arm_fir_q7.c | 397 |
1 files changed, 0 insertions, 397 deletions
diff --git a/DSP_Lib/Source/FilteringFunctions/arm_fir_q7.c b/DSP_Lib/Source/FilteringFunctions/arm_fir_q7.c deleted file mode 100644 index 24a50dc..0000000 --- a/DSP_Lib/Source/FilteringFunctions/arm_fir_q7.c +++ /dev/null @@ -1,397 +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_fir_q7.c -* -* Description: Q7 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 - * @{ - */ - -/** - * @param[in] *S points to an instance of the Q7 FIR filter 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. - * - * <b>Scaling and Overflow Behavior:</b> - * \par - * The function is implemented using a 32-bit internal accumulator. - * Both coefficients and state variables are represented in 1.7 format and multiplications yield a 2.14 result. - * The 2.14 intermediate results are accumulated in a 32-bit accumulator in 18.14 format. - * There is no risk of internal overflow with this approach and the full precision of intermediate multiplications is preserved. - * The accumulator is converted to 18.7 format by discarding the low 7 bits. - * Finally, the result is truncated to 1.7 format. - */ - -void arm_fir_q7( - const arm_fir_instance_q7 * S, - q7_t * pSrc, - q7_t * pDst, - uint32_t blockSize) -{ - -#ifndef ARM_MATH_CM0_FAMILY - - /* Run the below code for Cortex-M4 and Cortex-M3 */ - - q7_t *pState = S->pState; /* State pointer */ - q7_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ - q7_t *pStateCurnt; /* Points to the current sample of the state */ - q7_t x0, x1, x2, x3; /* Temporary variables to hold state */ - q7_t c0; /* Temporary variable to hold coefficient value */ - q7_t *px; /* Temporary pointer for state */ - q7_t *pb; /* Temporary pointer for coefficient buffer */ - q31_t acc0, acc1, acc2, acc3; /* Accumulators */ - uint32_t numTaps = S->numTaps; /* Number of filter coefficients in the filter */ - uint32_t i, 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 */ - *pStateCurnt++ = *pSrc++; - *pStateCurnt++ = *pSrc++; - *pStateCurnt++ = *pSrc++; - *pStateCurnt++ = *pSrc++; - - /* Set all accumulators to zero */ - acc0 = 0; - acc1 = 0; - acc2 = 0; - acc3 = 0; - - /* Initialize state pointer */ - px = pState; - - /* Initialize coefficient pointer */ - pb = pCoeffs; - - /* Read the first three samples from the state buffer: - * x[n-numTaps], x[n-numTaps-1], x[n-numTaps-2] */ - x0 = *(px++); - x1 = *(px++); - x2 = *(px++); - - /* Loop unrolling. Process 4 taps at a time. */ - tapCnt = numTaps >> 2; - i = tapCnt; - - while(i > 0u) - { - /* Read the b[numTaps] coefficient */ - c0 = *pb; - - /* Read x[n-numTaps-3] sample */ - x3 = *px; - - /* acc0 += b[numTaps] * x[n-numTaps] */ - acc0 += ((q15_t) x0 * c0); - - /* acc1 += b[numTaps] * x[n-numTaps-1] */ - acc1 += ((q15_t) x1 * c0); - - /* acc2 += b[numTaps] * x[n-numTaps-2] */ - acc2 += ((q15_t) x2 * c0); - - /* acc3 += b[numTaps] * x[n-numTaps-3] */ - acc3 += ((q15_t) x3 * c0); - - /* Read the b[numTaps-1] coefficient */ - c0 = *(pb + 1u); - - /* Read x[n-numTaps-4] sample */ - x0 = *(px + 1u); - - /* Perform the multiply-accumulates */ - acc0 += ((q15_t) x1 * c0); - acc1 += ((q15_t) x2 * c0); - acc2 += ((q15_t) x3 * c0); - acc3 += ((q15_t) x0 * c0); - - /* Read the b[numTaps-2] coefficient */ - c0 = *(pb + 2u); - - /* Read x[n-numTaps-5] sample */ - x1 = *(px + 2u); - - /* Perform the multiply-accumulates */ - acc0 += ((q15_t) x2 * c0); - acc1 += ((q15_t) x3 * c0); - acc2 += ((q15_t) x0 * c0); - acc3 += ((q15_t) x1 * c0); - - /* Read the b[numTaps-3] coefficients */ - c0 = *(pb + 3u); - - /* Read x[n-numTaps-6] sample */ - x2 = *(px + 3u); - - /* Perform the multiply-accumulates */ - acc0 += ((q15_t) x3 * c0); - acc1 += ((q15_t) x0 * c0); - acc2 += ((q15_t) x1 * c0); - acc3 += ((q15_t) x2 * c0); - - /* update coefficient pointer */ - pb += 4u; - px += 4u; - - /* Decrement the loop counter */ - i--; - } - - /* If the filter length is not a multiple of 4, compute the remaining filter taps */ - - i = numTaps - (tapCnt * 4u); - while(i > 0u) - { - /* Read coefficients */ - c0 = *(pb++); - - /* Fetch 1 state variable */ - x3 = *(px++); - - /* Perform the multiply-accumulates */ - acc0 += ((q15_t) x0 * c0); - acc1 += ((q15_t) x1 * c0); - acc2 += ((q15_t) x2 * c0); - acc3 += ((q15_t) x3 * c0); - - /* Reuse the present sample states for next sample */ - x0 = x1; - x1 = x2; - x2 = x3; - - /* Decrement the loop counter */ - i--; - } - - /* Advance the state pointer by 4 to process the next group of 4 samples */ - pState = pState + 4; - - /* The results in the 4 accumulators are in 2.62 format. Convert to 1.31 - ** Then store the 4 outputs in the destination buffer. */ - acc0 = __SSAT((acc0 >> 7u), 8); - *pDst++ = acc0; - acc1 = __SSAT((acc1 >> 7u), 8); - *pDst++ = acc1; - acc2 = __SSAT((acc2 >> 7u), 8); - *pDst++ = acc2; - acc3 = __SSAT((acc3 >> 7u), 8); - *pDst++ = acc3; - - /* Decrement the samples 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 % 4u; - - while(blkCnt > 0u) - { - /* Copy one sample at a time into state buffer */ - *pStateCurnt++ = *pSrc++; - - /* Set the accumulator to zero */ - acc0 = 0; - - /* Initialize state pointer */ - px = pState; - - /* Initialize Coefficient pointer */ - pb = (pCoeffs); - - i = numTaps; - - /* Perform the multiply-accumulates */ - do - { - acc0 += (q15_t) * (px++) * (*(pb++)); - i--; - } while(i > 0u); - - /* The result is in 2.14 format. Convert to 1.7 - ** Then store the output in the destination buffer. */ - *pDst++ = __SSAT((acc0 >> 7u), 8); - - /* 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; - - 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 */ - - uint32_t numTaps = S->numTaps; /* Number of taps in the filter */ - uint32_t i, blkCnt; /* Loop counters */ - q7_t *pState = S->pState; /* State pointer */ - q7_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ - q7_t *px, *pb; /* Temporary pointers to state and coeff */ - q31_t acc = 0; /* Accumlator */ - q7_t *pStateCurnt; /* Points to the current sample of the state */ - - - /* 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); - - /* Initialize blkCnt with blockSize */ - blkCnt = blockSize; - - /* Perform filtering upto BlockSize - BlockSize%4 */ - while(blkCnt > 0u) - { - /* Copy one sample at a time into state buffer */ - *pStateCurnt++ = *pSrc++; - - /* Set accumulator to zero */ - acc = 0; - - /* Initialize state pointer of type q7 */ - px = pState; - - /* Initialize coeff pointer of type q7 */ - pb = pCoeffs; - - - i = numTaps; - - while(i > 0u) - { - /* 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 += (q15_t) * px++ * *pb++; - i--; - } - - /* Store the 1.7 format filter output in destination buffer */ - *pDst++ = (q7_t) __SSAT((acc >> 7), 8); - - /* Advance the state pointer by 1 to process 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; - - - /* Copy numTaps number of values */ - i = (numTaps - 1u); - - /* Copy q7_t data */ - while(i > 0u) - { - *pStateCurnt++ = *pState++; - i--; - } - -#endif /* #ifndef ARM_MATH_CM0_FAMILY */ - -} - -/** - * @} end of FIR group - */ |