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crc16.h

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Max 2017-12-22 20:15:47 -05:00
parent e9a6e3806f
commit 682bd4abcb
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op25/gr-op25_repeater/lib/crc16.h Normal file
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/*
* This file is part of OP25
*
* This 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 3, or (at your option)
* any later version.
*
* This software 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 software; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#ifndef INCLUDED_CRC16_H
#define INCLUDED_CRC16_H
static inline uint16_t crc16(const uint8_t buf[], int len) {
uint32_t poly = (1<<12) + (1<<5) + (1<<0);
uint32_t crc = 0;
for(int i=0; i<len; i++) {
uint8_t bit = buf[i] & 1;
crc = ((crc << 1) | bit) & 0x1ffff;
if (crc & 0x10000)
crc = (crc & 0xffff) ^ poly;
}
crc = crc ^ 0xffff;
return crc & 0xffff;
}
#endif /* INCLUDED_CRC16_H */