1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_fir_init_f64.c
4 * Description: Floating-point FIR filter initialization function
5 *
6 * $Date: 13 September 2021
7 * $Revision: V1.10.0
8 *
9 * Target Processor: Cortex-M and Cortex-A cores
10 * -------------------------------------------------------------------- */
11 /*
12 * Copyright (C) 2010-2021 ARM Limited or its affiliates. All rights reserved.
13 *
14 * SPDX-License-Identifier: Apache-2.0
15 *
16 * Licensed under the Apache License, Version 2.0 (the License); you may
17 * not use this file except in compliance with the License.
18 * You may obtain a copy of the License at
19 *
20 * www.apache.org/licenses/LICENSE-2.0
21 *
22 * Unless required by applicable law or agreed to in writing, software
23 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
24 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
25 * See the License for the specific language governing permissions and
26 * limitations under the License.
27 */
28
29 #include "dsp/filtering_functions.h"
30
31 /**
32 @ingroup groupFilters
33 */
34
35 /**
36 @addtogroup FIR
37 @{
38 */
39
40 /**
41 @brief Initialization function for the floating-point FIR filter.
42 @param[in,out] S points to an instance of the floating-point FIR filter structure
43 @param[in] numTaps number of filter coefficients in the filter
44 @param[in] pCoeffs points to the filter coefficients buffer
45 @param[in] pState points to the state buffer
46 @param[in] blockSize number of samples processed per call
47
48 @par Details
49 <code>pCoeffs</code> points to the array of filter coefficients stored in time reversed order:
50 <pre>
51 {b[numTaps-1], b[numTaps-2], b[N-2], ..., b[1], b[0]}
52 </pre>
53 @par
54 <code>pState</code> points to the array of state variables.
55 <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_f64()</code>.
56
57 @par
58 There is no Helium version of the fir F64.
59
60 */
61
arm_fir_init_f64(arm_fir_instance_f64 * S,uint16_t numTaps,const float64_t * pCoeffs,float64_t * pState,uint32_t blockSize)62 ARM_DSP_ATTRIBUTE void arm_fir_init_f64(
63 arm_fir_instance_f64 * S,
64 uint16_t numTaps,
65 const float64_t * pCoeffs,
66 float64_t * pState,
67 uint32_t blockSize)
68 {
69 /* Assign filter taps */
70 S->numTaps = numTaps;
71
72 /* Assign coefficient pointer */
73 S->pCoeffs = pCoeffs;
74
75 /* Clear state buffer. The size is always (blockSize + numTaps - 1) */
76 memset(pState, 0, (numTaps + (blockSize - 1U)) * sizeof(float64_t));
77 /* Assign state pointer */
78 S->pState = pState;
79 }
80
81 /**
82 @} end of FIR group
83 */
84
