arm_fir_init_q31.c
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CLexer
r71 | /* ---------------------------------------------------------------------- | |||
* Copyright (C) 2010 ARM Limited. All rights reserved. | ||||
* | ||||
* $Date: 15. July 2011 | ||||
* $Revision: V1.0.10 | ||||
* | ||||
* Project: CMSIS DSP Library | ||||
* Title: arm_fir_init_q31.c | ||||
* | ||||
* Description: Q31 FIR filter initialization function. | ||||
* | ||||
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0 | ||||
* | ||||
* Version 1.0.10 2011/7/15 | ||||
* Big Endian support added and Merged M0 and M3/M4 Source code. | ||||
* | ||||
* Version 1.0.3 2010/11/29 | ||||
* Re-organized the CMSIS folders and updated documentation. | ||||
* | ||||
* Version 1.0.2 2010/11/11 | ||||
* Documentation updated. | ||||
* | ||||
* Version 1.0.1 2010/10/05 | ||||
* Production release and review comments incorporated. | ||||
* | ||||
* Version 1.0.0 2010/09/20 | ||||
* Production release and review comments incorporated. | ||||
* | ||||
* Version 0.0.5 2010/04/26 | ||||
* incorporated review comments and updated with latest CMSIS layer | ||||
* | ||||
* Version 0.0.3 2010/03/10 | ||||
* Initial version | ||||
* -------------------------------------------------------------------- */ | ||||
#include "arm_math.h" | ||||
/** | ||||
* @ingroup groupFilters | ||||
*/ | ||||
/** | ||||
* @addtogroup FIR | ||||
* @{ | ||||
*/ | ||||
/** | ||||
* @details | ||||
* | ||||
* @param[in,out] *S points to an instance of the Q31 FIR filter structure. | ||||
* @param[in] numTaps Number of filter coefficients in the filter. | ||||
* @param[in] *pCoeffs points to the filter coefficients buffer. | ||||
* @param[in] *pState points to the state buffer. | ||||
* @param[in] blockSize number of samples that are processed per call. | ||||
* @return none. | ||||
* | ||||
* <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> | ||||
* \par | ||||
* <code>pState</code> points to the array of state variables. | ||||
* <code>pState</code> is of length <code>numTaps+blockSize-1</code> samples, where <code>blockSize</code> is the number of input samples processed by each call to <code>arm_fir_q31()</code>. | ||||
*/ | ||||
void arm_fir_init_q31( | ||||
arm_fir_instance_q31 * S, | ||||
uint16_t numTaps, | ||||
q31_t * pCoeffs, | ||||
q31_t * pState, | ||||
uint32_t blockSize) | ||||
{ | ||||
/* Assign filter taps */ | ||||
S->numTaps = numTaps; | ||||
/* Assign coefficient pointer */ | ||||
S->pCoeffs = pCoeffs; | ||||
/* Clear state buffer and state array size is (blockSize + numTaps - 1) */ | ||||
memset(pState, 0, (blockSize + ((uint32_t) numTaps - 1u)) * sizeof(q31_t)); | ||||
/* Assign state pointer */ | ||||
S->pState = pState; | ||||
} | ||||
/** | ||||
* @} end of FIR group | ||||
*/ | ||||