105 lines
2.9 KiB
C++
105 lines
2.9 KiB
C++
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/* Copyright (c) 2002, 2003, 2004 Marek Michalkiewicz
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Copyright (c) 2005, 2007 Joerg Wunsch
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the
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distribution.
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* Neither the name of the copyright holders nor the names of
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE. */
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// Port to Energia / MPS430 by Yannick DEVOS XV4Y - (c) 2013
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// http://xv4y.radioclub.asia/
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//
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// Adapted to RadioHead use by Mike McCauley 2014
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// This is to prevent name collisions with other similar library functions
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// and to provide a consistent API amonng all processors
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//
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/* $Id: RHCRC.cpp,v 1.1 2014/06/24 02:40:12 mikem Exp $ */
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#include <RHCRC.h>
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#define lo8(x) ((x)&0xff)
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#define hi8(x) ((x)>>8)
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uint16_t RHcrc16_update(uint16_t crc, uint8_t a)
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{
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int i;
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crc ^= a;
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for (i = 0; i < 8; ++i)
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{
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if (crc & 1)
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crc = (crc >> 1) ^ 0xA001;
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else
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crc = (crc >> 1);
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}
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return crc;
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}
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uint16_t RHcrc_xmodem_update (uint16_t crc, uint8_t data)
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{
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int i;
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crc = crc ^ ((uint16_t)data << 8);
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for (i=0; i<8; i++)
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{
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if (crc & 0x8000)
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crc = (crc << 1) ^ 0x1021;
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else
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crc <<= 1;
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}
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return crc;
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}
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uint16_t RHcrc_ccitt_update (uint16_t crc, uint8_t data)
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{
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data ^= lo8 (crc);
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data ^= data << 4;
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return ((((uint16_t)data << 8) | hi8 (crc)) ^ (uint8_t)(data >> 4)
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^ ((uint16_t)data << 3));
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}
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uint8_t RHcrc_ibutton_update(uint8_t crc, uint8_t data)
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{
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uint8_t i;
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crc = crc ^ data;
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for (i = 0; i < 8; i++)
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{
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if (crc & 0x01)
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crc = (crc >> 1) ^ 0x8C;
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else
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crc >>= 1;
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}
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return crc;
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}
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