Project Ne10
An open, optimized software library for the ARM architecture.
NE10_sample_fir.c

An example of using Ne10's vanilla FIR function.

/*
* Copyright 2011-16 ARM Limited and Contributors.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of ARM Limited nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY ARM LIMITED AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL ARM LIMITED AND CONTRIBUTORS BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#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;
}