mirror of
https://github.com/portapack-mayhem/mayhem-firmware.git
synced 2024-12-14 20:18:13 +00:00
45 lines
1.4 KiB
C++
45 lines
1.4 KiB
C++
/*
|
|
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
|
|
*
|
|
* This file is part of PortaPack.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2, or (at your option)
|
|
* any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; see the file COPYING. If not, write to
|
|
* the Free Software Foundation, Inc., 51 Franklin Street,
|
|
* Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#include "access_code_correlator.hpp"
|
|
|
|
void AccessCodeCorrelator::configure(
|
|
const uint32_t new_code,
|
|
const size_t new_code_length,
|
|
const size_t new_maximum_hamming_distance
|
|
) {
|
|
if( new_code_length <= 32 ) {
|
|
code = new_code;
|
|
mask = mask_value(new_code_length);
|
|
maximum_hamming_distance = new_maximum_hamming_distance;
|
|
}
|
|
}
|
|
|
|
bool AccessCodeCorrelator::execute(
|
|
const uint_fast8_t in
|
|
) {
|
|
history = (history << 1) | (in & 1);
|
|
const auto delta_bits = (history ^ code) & mask;
|
|
//const size_t count = __builtin_popcountll(delta_bits);
|
|
const size_t count = __builtin_popcountl(delta_bits);
|
|
return (count <= maximum_hamming_distance);
|
|
}
|