Crc8.cpp

#include "Crc8.h"

/**************************************************************************************************/
/*  CRC8 helper class functions.                                                                  */
/**************************************************************************************************/

/**
 *  \brief            CRC8 class constructor.
 *  \param [in] poly  8 bit CRC polynomial to use.
 */
CRC8::CRC8(uint8_t poly) {crc8Start(poly);}

/**
 *  \brief            Return the current value of the CRC.
 *  \return           8 bit CRC current value.
 */
uint8_t CRC8::crc8(void) {return _crc;}

/**
 *  \brief            Update the current value of the CRC.
 *  \param [in] data  New 8 bit data to be added to the CRC.
 *  \return           8 bit CRC current value.
 */
uint8_t CRC8::crc8(uint8_t data) {
    uint8_t i = 8;

    _crc ^= data;
    while(i--) _crc = _crc & 0x80 ? (_crc << 1) ^ _poly : _crc << 1;
    return _crc;
}

/**
 *  \brief            Initialize the CRC8 object.
 *  \param [in] poly  8 bit CRC polynomial to use.
 */
void CRC8::crc8Start(uint8_t poly) {
    _poly = poly;
    _crc = 0;
}