#include "tinycrc.h"

/*
    CRC16
*/

uint16_t tinycrc_crc16(const uint8_t *data, uint16_t size)
{
    unsigned char x;
    unsigned short crc = 0xFFFF;

    if (data == nullptr) {
        return 0;
    }

    for (int index = 0 ; index < size ; ++index) {
        x = crc >> 8 ^ *data++;
        x ^= x>>4;
        crc = (crc << 8) ^ ((unsigned short)(x << 12)) ^ ((unsigned short)(x <<5)) ^ ((unsigned short)x);
    }
    return crc & 0xFFFF;
}