1 /* ----------------------------------------------------------------------
2 * Project: CMSIS DSP Library
3 * Title: arm_fir_lattice_init_q31.c
4 * Description: Q31 FIR lattice filter initialization function
5 *
6 * $Date: 23 April 2021
7 * $Revision: V1.9.0
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_Lattice
37 @{
38 */
39
40 /**
41 @brief Initialization function for the Q31 FIR lattice filter.
42 @param[in] S points to an instance of the Q31 FIR lattice structure
43 @param[in] numStages number of filter stages
44 @param[in] pCoeffs points to the coefficient buffer. The array is of length numStages
45 @param[in] pState points to the state buffer. The array is of length numStages
46 */
47
arm_fir_lattice_init_q31(arm_fir_lattice_instance_q31 * S,uint16_t numStages,const q31_t * pCoeffs,q31_t * pState)48 void arm_fir_lattice_init_q31(
49 arm_fir_lattice_instance_q31 * S,
50 uint16_t numStages,
51 const q31_t * pCoeffs,
52 q31_t * pState)
53 {
54 /* Assign filter taps */
55 S->numStages = numStages;
56
57 /* Assign coefficient pointer */
58 S->pCoeffs = pCoeffs;
59
60 /* Clear state buffer and size is always numStages */
61 memset(pState, 0, (numStages) * sizeof(q31_t));
62
63 /* Assign state pointer */
64 S->pState = pState;
65 }
66
67 /**
68 @} end of FIR_Lattice group
69 */
70
