NE10_sample_fir.c

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#include <stdio.h>
#include <stdlib.h>

#include "NE10.h"

#define NUMTAPS   4
#define NUMBLOCKS 2
#define BLOCKSIZE 8
#define BUFFSIZE  (NUMBLOCKS * BLOCKSIZE)

int fir_sample_main(void)
{
    ne10_float32_t src[BUFFSIZE]; // A source array of input data
    ne10_float32_t dst[BUFFSIZE]; // A destination array for the transformed data
    ne10_float32_t st[NUMTAPS + BLOCKSIZE - 1]; // A "state" buffer for use within the FIR
    ne10_float32_t coeffs[NUMTAPS]; // An array of FIR coefficients (in reverse order)
    ne10_fir_instance_f32_t cfg;    // An FIR "instance structure"

    // Initialise Ne10, using hardware auto-detection to set library function pointers
    if (ne10_init() != NE10_OK)
    {
        fprintf(stderr, "Failed to initialise Ne10.\n");
        return 1;
    }

    // Prepare the FIR instance structure, storing `NUMTAPS`, `coeffs`, and `st` within
    // it, and clearing the state buffer. (For constant parameters, this process can
    // instead be performed manually.)
    if (ne10_fir_init_float(&cfg, NUMTAPS, coeffs, st, BLOCKSIZE) != NE10_OK)
    {
        fprintf(stderr, "Failed to initialise FIR instance structure.\n");
        return 1;
    }

    // Generate test coefficient values
    for (int i = 0; i < NUMTAPS; i++)
    {
        coeffs[i] = (ne10_float32_t)rand() / RAND_MAX * 5.0f;
    }

    // Generate test input values
    for (int i = 0; i < BUFFSIZE; i++)
    {
        src[i] = (ne10_float32_t)rand() / RAND_MAX * 20.0f;
    }

    // Perform the FIR filtering of the input buffer in `NUMBLOCKS` blocks of `BLOCKSIZE`
    // elements using the parameters set up in the FIR instance structure `cfg`.
    for (int b = 0; b < NUMBLOCKS; b++)
    {
        ne10_fir_float(&cfg, src + (b * BLOCKSIZE), dst + (b * BLOCKSIZE), BLOCKSIZE);
    }

    // Display the results (dst[i] = b[0] * src[i] + b[1] * src[i - 1] + b[2] * src[i - 2]
    //                               + ... + b[NUMTAPS - 1] * src[i - (NUMTAPS - 1)])
    printf("Coefficients:\n");
    for (int i = NUMTAPS - 1; i >= 0; i--)
    {
        printf("\tb[%d] = %5.4f\n", NUMTAPS - (i + 1), coeffs[i]);
    }
    for (int i = 0; i < BUFFSIZE; i++)
    {
        printf( "IN[%2d]: %9.4f\t", i, src[i]);
        printf("OUT[%2d]: %9.4f\n", i, dst[i]);
    }

    return 0;
}