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CANopenNode/301/crc16-ccitt.h
Janez a528eb1669 Better organised configuration macros (CO_config.h):
- rearranged and better documented
 - default values moved from CO_driver.h into appropriate files
 - rearranged also in CO_driver_target.h files
 - parts of the stack or whole objects can be disabled.
 - configuration is verified for depencies

Additional:
 - renamed some members of CO_Default_CAN_ID_t
 - moved helpers CO_setUint32() etc from CO_SDOserver.h into CO_driver.h.
 - change wrong CO_ERROR_PARAMETERS to CO_ERROR_ILLEGAL_ARGUMENT.
 - renamed CO_ERROR_PARAMETERS to CO_ERROR_OD_PARAMETERS
2020-09-14 15:50:21 +02:00

92 lines
2.4 KiB
C

/**
* Calculation of CRC 16 CCITT polynomial.
*
* @file crc16-ccitt.h
* @ingroup CO_crc16_ccitt
* @author Lammert Bies
* @author Janez Paternoster
* @copyright 2012 - 2020 Janez Paternoster
*
* This file is part of CANopenNode, an opensource CANopen Stack.
* Project home page is <https://github.com/CANopenNode/CANopenNode>.
* For more information on CANopen see <http://www.can-cia.org/>.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef CRC16_CCITT_H
#define CRC16_CCITT_H
#include "301/CO_driver.h"
/* default configuration, see CO_config.h */
#ifndef CO_CONFIG_CRC16
#define CO_CONFIG_CRC16 (0)
#endif
#if ((CO_CONFIG_CRC16) & CO_CONFIG_CRC16_ENABLE) || defined CO_DOXYGEN
#ifdef __cplusplus
extern "C" {
#endif
/**
* @defgroup CO_crc16_ccitt CRC 16 CCITT
* @ingroup CO_CANopen_301
* @{
*
* Calculation of CRC 16 CCITT polynomial.
*
* Equation:
*
* `x^16 + x^12 + x^5 + 1`
*/
/**
* Update crc16_ccitt variable with one data byte
*
* This function updates crc variable for one data byte using crc16 ccitt
* algorithm.
*
* @param [in,out] crc Externally defined variable for CRC checksum. Before
* start of new CRC calculation, variable must be initialized (zero for xmodem).
* @param chr One byte of data
*/
void crc16_ccitt_single(uint16_t *crc, const uint8_t chr);
/**
* Calculate CRC sum on block of data.
*
* @param block Pointer to block of data.
* @param blockLength Length of data in bytes;
* @param crc Initial value (zero for xmodem). If block is split into
* multiple segments, previous CRC is used as initial.
*
* @return Calculated CRC.
*/
uint16_t crc16_ccitt(const uint8_t block[],
size_t blockLength,
uint16_t crc);
/** @} */ /* CO_crc16_ccitt */
#ifdef __cplusplus
}
#endif /*__cplusplus*/
#endif /* (CO_CONFIG_CRC16) & CO_CONFIG_CRC16_ENABLE */
#endif /* CRC16_CCITT_H */