32 lines
1.2 KiB
C++
32 lines
1.2 KiB
C++
/**
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* Marlin 3D Printer Firmware
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* Copyright (c) 2019 MarlinFirmware [https://github.com/MarlinFirmware/Marlin]
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*
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* Based on Sprinter and grbl.
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* Copyright (c) 2011 Camiel Gubbels / Erik van der Zalm
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*
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* This program is free software: you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation, either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include "crc16.h"
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void crc16(uint16_t *crc, const void * const data, uint16_t cnt) {
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uint8_t *ptr = (uint8_t *)data;
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while (cnt--) {
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*crc = (uint16_t)(*crc ^ (uint16_t)(((uint16_t)*ptr++) << 8));
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for (uint8_t i = 0; i < 8; i++)
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*crc = (uint16_t)((*crc & 0x8000) ? ((uint16_t)(*crc << 1) ^ 0x1021) : (*crc << 1));
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}
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}
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