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Diffstat (limited to 'tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_decimate_q31.c')
-rw-r--r-- | tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_decimate_q31.c | 311 |
1 files changed, 0 insertions, 311 deletions
diff --git a/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_decimate_q31.c b/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_decimate_q31.c deleted file mode 100644 index 8c75e7f63c..0000000000 --- a/tmk_core/tool/mbed/mbed-sdk/libraries/dsp/cmsis_dsp/FilteringFunctions/arm_fir_decimate_q31.c +++ /dev/null @@ -1,311 +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_decimate_q31.c -* -* Description: Q31 FIR Decimator. -* -* 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_decimate - * @{ - */ - -/** - * @brief Processing function for the Q31 FIR decimator. - * @param[in] *S points to an instance of the Q31 FIR decimator 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 input samples to process per call. - * @return none - * - * <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 log2(numTaps) bits (where log2 is read as log to the base 2). - * After all multiply-accumulates are performed, the 2.62 accumulator is truncated to 1.32 format and then saturated to 1.31 format. - * - * \par - * Refer to the function <code>arm_fir_decimate_fast_q31()</code> for a faster but less precise implementation of this function for Cortex-M3 and Cortex-M4. - */ - -void arm_fir_decimate_q31( - const arm_fir_decimate_instance_q31 * S, - q31_t * pSrc, - q31_t * pDst, - uint32_t blockSize) -{ - q31_t *pState = S->pState; /* State pointer */ - q31_t *pCoeffs = S->pCoeffs; /* Coefficient pointer */ - q31_t *pStateCurnt; /* Points to the current sample of the state */ - q31_t x0, c0; /* Temporary variables to hold state and coefficient values */ - q31_t *px; /* Temporary pointers for state buffer */ - q31_t *pb; /* Temporary pointers for coefficient buffer */ - q63_t sum0; /* Accumulator */ - uint32_t numTaps = S->numTaps; /* Number of taps */ - uint32_t i, tapCnt, blkCnt, outBlockSize = blockSize / S->M; /* Loop counters */ - - -#ifndef ARM_MATH_CM0_FAMILY - - /* Run the below code for Cortex-M4 and Cortex-M3 */ - - /* 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); - - /* Total number of output samples to be computed */ - blkCnt = outBlockSize; - - while(blkCnt > 0u) - { - /* Copy decimation factor number of new input samples into the state buffer */ - i = S->M; - - do - { - *pStateCurnt++ = *pSrc++; - - } while(--i); - - /* Set accumulator to zero */ - sum0 = 0; - - /* Initialize state pointer */ - px = pState; - - /* Initialize coeff pointer */ - pb = pCoeffs; - - /* Loop unrolling. Process 4 taps at a time. */ - tapCnt = numTaps >> 2; - - /* Loop over the number of taps. Unroll by a factor of 4. - ** Repeat until we've computed numTaps-4 coefficients. */ - while(tapCnt > 0u) - { - /* Read the b[numTaps-1] coefficient */ - c0 = *(pb++); - - /* Read x[n-numTaps-1] sample */ - x0 = *(px++); - - /* Perform the multiply-accumulate */ - sum0 += (q63_t) x0 *c0; - - /* Read the b[numTaps-2] coefficient */ - c0 = *(pb++); - - /* Read x[n-numTaps-2] sample */ - x0 = *(px++); - - /* Perform the multiply-accumulate */ - sum0 += (q63_t) x0 *c0; - - /* Read the b[numTaps-3] coefficient */ - c0 = *(pb++); - - /* Read x[n-numTaps-3] sample */ - x0 = *(px++); - - /* Perform the multiply-accumulate */ - sum0 += (q63_t) x0 *c0; - - /* Read the b[numTaps-4] coefficient */ - c0 = *(pb++); - - /* Read x[n-numTaps-4] sample */ - x0 = *(px++); - - /* Perform the multiply-accumulate */ - sum0 += (q63_t) x0 *c0; - - /* Decrement the loop counter */ - tapCnt--; - } - - /* If the filter length is not a multiple of 4, compute the remaining filter taps */ - tapCnt = numTaps % 0x4u; - - while(tapCnt > 0u) - { - /* Read coefficients */ - c0 = *(pb++); - - /* Fetch 1 state variable */ - x0 = *(px++); - - /* Perform the multiply-accumulate */ - sum0 += (q63_t) x0 *c0; - - /* Decrement the loop counter */ - tapCnt--; - } - - /* Advance the state pointer by the decimation factor - * to process the next group of decimation factor number samples */ - pState = pState + S->M; - - /* The result is in the accumulator, store in the destination buffer. */ - *pDst++ = (q31_t) (sum0 >> 31); - - /* 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; - - i = (numTaps - 1u) >> 2u; - - /* copy data */ - while(i > 0u) - { - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - i--; - } - - i = (numTaps - 1u) % 0x04u; - - /* copy data */ - while(i > 0u) - { - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - i--; - } - -#else - -/* Run the below code for Cortex-M0 */ - - /* 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); - - /* Total number of output samples to be computed */ - blkCnt = outBlockSize; - - while(blkCnt > 0u) - { - /* Copy decimation factor number of new input samples into the state buffer */ - i = S->M; - - do - { - *pStateCurnt++ = *pSrc++; - - } while(--i); - - /* Set accumulator to zero */ - sum0 = 0; - - /* Initialize state pointer */ - px = pState; - - /* Initialize coeff pointer */ - pb = pCoeffs; - - tapCnt = numTaps; - - while(tapCnt > 0u) - { - /* Read coefficients */ - c0 = *pb++; - - /* Fetch 1 state variable */ - x0 = *px++; - - /* Perform the multiply-accumulate */ - sum0 += (q63_t) x0 *c0; - - /* Decrement the loop counter */ - tapCnt--; - } - - /* Advance the state pointer by the decimation factor - * to process the next group of decimation factor number samples */ - pState = pState + S->M; - - /* The result is in the accumulator, store in the destination buffer. */ - *pDst++ = (q31_t) (sum0 >> 31); - - /* Decrement the loop counter */ - blkCnt--; - } - - /* Processing is complete. - ** Now copy the last numTaps - 1 samples to the start 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; - - i = numTaps - 1u; - - /* copy data */ - while(i > 0u) - { - *pStateCurnt++ = *pState++; - - /* Decrement the loop counter */ - i--; - } - -#endif /* #ifndef ARM_MATH_CM0_FAMILY */ - -} - -/** - * @} end of FIR_decimate group - */ |