xF5Cuv - Online C++ Compiler & Debugging Tool

#include <stdio.h>
#include <stdint.h>

uint8_t crc2(uint8_t data) {
    uint8_t poly = 0x07;   // CRC-2 polynomial (111)
    uint8_t crc = 0x00;

    for (int i = 0; i < 8; i++) {
        uint8_t bit = ((data >> (7 - i)) & 1) ^ ((crc >> 1) & 1);
        crc = (crc << 1) & 0x03; // keep only 2 bits

        if (bit)
            crc ^= poly & 0x03;  // apply CRC-2 polynomial
    }
    return crc & 0x03;
}

int main() {
    uint8_t data = 0xAB;
    uint8_t result = crc2(data);

    printf("CRC-2 of 0x%X = %u\n", data, result);
    return 0;
}