dsps_fird_init_f32.c File Reference

#include "dsps_fir.h"

Include dependency graph for dsps_fird_init_f32.c:

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Functions
esp_err_t	dsps_fird_init_f32 (fir_f32_t *fir, float *coeffs, float *delay, int N, int decim)
	initialize structure for 32 bit Decimation FIR filter Function initialize structure for 32 bit floating point FIR filter with decimation The implementation use ANSI C and could be compiled and run on any platform

Function Documentation

dsps_fird_init_f32()

esp_err_t dsps_fird_init_f32	(	fir_f32_t *	fir,
		float *	coeffs,
		float *	delay,
		int	N,
		int	decim )

initialize structure for 32 bit Decimation FIR filter Function initialize structure for 32 bit floating point FIR filter with decimation The implementation use ANSI C and could be compiled and run on any platform

Parameters

fir	pointer to fir filter structure, that must be preallocated
coeffs	array with FIR filter coefficients. Must be length N
delay	array for FIR filter delay line. Must be length N
N	FIR filter length. Length of coeffs and delay arrays.
decim	decimation factor.

Returns

• ESP_OK on success
• One of the error codes from DSP library

Definition at line 18 of file dsps_fird_init_f32.c.

{
    fir->coeffs = coeffs;
    fir->delay = delay;
    fir->N = N;
    fir->pos = 0;
    fir->decim = decim;
 
#ifdef CONFIG_IDF_TARGET_ESP32S3
    // The amount of coefficients should be divided to 4,
    // if not, add zero coefficients to round length to 0
    if (fir->N % 4 != 0) {
        return ESP_ERR_DSP_INVALID_LENGTH;
    }
    // The coeffs array should be aligned to 16
    if (((uint32_t)coeffs) & 0x0f) {
        return ESP_ERR_DSP_ARRAY_NOT_ALIGNED;
    }
    // The delay array should be aligned to 16
    if (((uint32_t)delay) & 0x0f) {
        return ESP_ERR_DSP_ARRAY_NOT_ALIGNED;
    }
#endif // CONFIG_IDF_TARGET_ESP32S3
 
    for (int i = 0 ; i < N; i++) {
        fir->delay[i] = 0;
    }
    return ESP_OK;
}

References coeffs, fir_f32_s::coeffs, fir_f32_s::decim, delay, fir_f32_s::delay, ESP_ERR_DSP_ARRAY_NOT_ALIGNED, ESP_ERR_DSP_INVALID_LENGTH, ESP_OK, fir_f32_s::N, N, and fir_f32_s::pos.