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Diffstat (limited to 'platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_init_q15.c')
| -rw-r--r-- | platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_init_q15.c | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_init_q15.c b/platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_init_q15.c new file mode 100644 index 0000000..b449c30 --- /dev/null +++ b/platform/CMSIS/DSP_Lib/Source/FilteringFunctions/arm_fir_init_q15.c @@ -0,0 +1,154 @@ +/* ---------------------------------------------------------------------- +* Copyright (C) 2010-2014 ARM Limited. All rights reserved. +* +* $Date: 12. March 2014 +* $Revision: V1.4.4 +* +* Project: CMSIS DSP Library +* Title: arm_fir_init_q15.c +* +* Description: Q15 FIR filter initialization 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,out] *S points to an instance of the Q15 FIR filter structure. + * @param[in] numTaps Number of filter coefficients in the filter. Must be even and greater than or equal to 4. + * @param[in] *pCoeffs points to the filter coefficients buffer. + * @param[in] *pState points to the state buffer. + * @param[in] blockSize is number of samples processed per call. + * @return The function returns ARM_MATH_SUCCESS if initialization is successful or ARM_MATH_ARGUMENT_ERROR if + * <code>numTaps</code> is not greater than or equal to 4 and even. + * + * <b>Description:</b> + * \par + * <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order: + * <pre> + * {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]} + * </pre> + * Note that <code>numTaps</code> must be even and greater than or equal to 4. + * To implement an odd length filter simply increase <code>numTaps</code> by 1 and set the last coefficient to zero. + * For example, to implement a filter with <code>numTaps=3</code> and coefficients + * <pre> + * {0.3, -0.8, 0.3} + * </pre> + * set <code>numTaps=4</code> and use the coefficients: + * <pre> + * {0.3, -0.8, 0.3, 0}. + * </pre> + * Similarly, to implement a two point filter + * <pre> + * {0.3, -0.3} + * </pre> + * set <code>numTaps=4</code> and use the coefficients: + * <pre> + * {0.3, -0.3, 0, 0}. + * </pre> + * \par + * <code>pState</code> points to the array of state variables. + * <code>pState</code> is of length <code>numTaps+blockSize</code>, when running on Cortex-M4 and Cortex-M3 and is of length <code>numTaps+blockSize-1</code>, when running on Cortex-M0 where <code>blockSize</code> is the number of input samples processed by each call to <code>arm_fir_q15()</code>. + */ + +arm_status arm_fir_init_q15( + arm_fir_instance_q15 * S, + uint16_t numTaps, + q15_t * pCoeffs, + q15_t * pState, + uint32_t blockSize) +{ + arm_status status; + + +#ifndef ARM_MATH_CM0_FAMILY + + /* Run the below code for Cortex-M4 and Cortex-M3 */ + + /* The Number of filter coefficients in the filter must be even and at least 4 */ + if(numTaps & 0x1u) + { + status = ARM_MATH_ARGUMENT_ERROR; + } + else + { + /* Assign filter taps */ + S->numTaps = numTaps; + + /* Assign coefficient pointer */ + S->pCoeffs = pCoeffs; + + /* Clear the state buffer. The size is always (blockSize + numTaps ) */ + memset(pState, 0, (numTaps + (blockSize)) * sizeof(q15_t)); + + /* Assign state pointer */ + S->pState = pState; + + status = ARM_MATH_SUCCESS; + } + + return (status); + +#else + + /* Run the below code for Cortex-M0 */ + + /* Assign filter taps */ + S->numTaps = numTaps; + + /* Assign coefficient pointer */ + S->pCoeffs = pCoeffs; + + /* Clear the state buffer. The size is always (blockSize + numTaps - 1) */ + memset(pState, 0, (numTaps + (blockSize - 1u)) * sizeof(q15_t)); + + /* Assign state pointer */ + S->pState = pState; + + status = ARM_MATH_SUCCESS; + + return (status); + +#endif /* #ifndef ARM_MATH_CM0_FAMILY */ + +} + +/** + * @} end of FIR group + */ |