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43 lines
839 B
C
43 lines
839 B
C
/*
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* Copyright (C) 2018 Gunar Schorcht
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*
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* This file is subject to the terms and conditions of the GNU Lesser
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* General Public License v2.1. See the file LICENSE in the top level
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* directory for more details.
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*/
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/**
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* @ingroup sys_checksum_crc8
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* @brief CRC-8 checksum algorithms
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*
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* @{
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*
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* @file
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* @brief CRC-8 implementation
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*
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* @author Gunar Schorcht <gunar@schorcht.net>
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*/
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#include <stdbool.h>
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#include "checksum/crc8.h"
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uint8_t crc8(const uint8_t *data, size_t len, uint8_t g_polynom, uint8_t crc)
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{
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/* iterate over all bytes */
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for (size_t i=0; i < len; i++)
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{
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crc ^= data[i];
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for (int i = 0; i < 8; i++)
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{
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bool xor = crc & 0x80;
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crc = crc << 1;
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crc = xor ? crc ^ g_polynom : crc;
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}
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}
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return crc;
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}
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/** @} */
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