| /* ---------------------------------------------------------------------- |
| * 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 |
| */ |
