23 lines
594 B
C
23 lines
594 B
C
// Code for crc16_ccitt
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//
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// Copyright (C) 2016 Kevin O'Connor <kevin@koconnor.net>
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//
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// This file may be distributed under the terms of the GNU GPLv3 license.
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#include "misc.h" // crc16_ccitt
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// Implement the standard crc "ccitt" algorithm on the given buffer
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uint16_t
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crc16_ccitt(uint8_t *buf, uint_fast8_t len)
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{
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uint16_t crc = 0xffff;
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while (len--) {
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uint8_t data = *buf++;
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data ^= crc & 0xff;
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data ^= data << 4;
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crc = ((((uint16_t)data << 8) | (crc >> 8)) ^ (uint8_t)(data >> 4)
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^ ((uint16_t)data << 3));
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}
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return crc;
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}
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