/**
* @file ALGO_CRC_ATY.c
*
* @param Project ALGO_Algorithm_ATY_LIB
*
* @author ATY
*
* @copyright
*       - Copyright 2017 - 2025 MZ-ATY
*       - This code follows:
*           - MZ-ATY Various Contents Joint Statement -
*               <a href="https://mengze.top/MZ-ATY_VCJS">
*                        https://mengze.top/MZ-ATY_VCJS</a>
*           - CC 4.0 BY-NC-SA -
*               <a href="https://creativecommons.org/licenses/by-nc-sa/4.0/">
*                        https://creativecommons.org/licenses/by-nc-sa/4.0/</a>
*       - Your use will be deemed to have accepted the terms of this statement.
*
* @brief Familiar functions of CRC16 Modbus(others to be supplemented) for all codes
*
* @version
*       - 1_01_200318 > ATY
*           -# Preliminary version, first Release
*       - 1_03_200318 > ATY
*           -# Add Conditional Compilation
*           -# Add user port
*       - 1_05_200722 > ATY
*           -# Change parameters
*       - 1_06_221210 > ATY
*           -# Tested
**********************************************************************************
*/


#ifndef __ALGO_CRC_ATY_C
#define __ALGO_CRC_ATY_C

#include "ALGO_CRC_ATY.h"

/******************************* For user *************************************/

/******************************************************************************/

#ifndef __CRC_CALC_ATY
static __CODE const uint16_t CRC16Table[256] = {
    0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
    0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
    0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
    0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
    0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
    0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
    0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
    0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
    0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
    0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
    0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
    0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
    0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
    0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
    0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
    0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
    0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
    0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
    0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
    0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
    0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
    0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
    0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
    0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
    0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
    0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
    0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
    0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
    0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
    0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
    0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
    0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040
};

/**
 * @brief   Generate CRC of Modbus 16
 * @param   buf Generate buf
 * @param   size Input source buf
 * @return  Value of CRC generate
 */
uint16_t GenCrc16Modbus(uint8_t* buf, uint8_t size)
{
    uint16_t crcResult = 0xFFFF, tableIndex = 0;
    uint8_t i = 0;

    for(i = 0; i < size; i++)
    {
        tableIndex = ((crcResult & 0x00FF) ^ (buf[i] & 0xFF));
        crcResult = ((crcResult >> 8) & 0xFF) ^ CRC16Table[tableIndex];
    }

    return crcResult;
}

#else

/**
 * @brief   Generate CRC of Modbus 16
 * @param   buf Generate buf
 * @param   size Input source buf
 * @return  Value of CRC generate
 * @note    Size not include crc byte
 */
uint16_t GenCrc16Modbus(uint8_t* buf, uint8_t size)
{
    const uint16_t crcXorMultinomial = 0x8005;
    uint16_t crcXorResult = 0xFFFF;
    uint8_t temp_uint8 = 0;
    uint8_t i = 0;

    while(size--)
    {
        temp_uint8 = *(buf++);
        ALGO_InvertUint8_Group(&temp_uint8, &temp_uint8);
        crcXorResult ^= (temp_uint8 << 8);

        for(i = 0; i < 8; i++)
        {
            if(crcXorResult & 0x8000)
                crcXorResult = (crcXorResult << 1) ^ crcXorMultinomial;
            else
                crcXorResult = crcXorResult << 1;
        }
    }
    ALGO_InvertUint16_Group(&crcXorResult, &crcXorResult);
    return crcXorResult;
}
#endif /* __CRC_CALC_ATY */

/**
 * @brief   Generate CRC of Modbus 16 with high bit or low bit
 * @param   buf Generate buf
 * @param   size Input source buf
 * @param   highLow Choose output high bit or low bit, 1 is high, 0 is low
 * @return  Value of CRC generate in high bit or low bit
 * @note    Size not include crc byte
 */
uint8_t GenCrc16ModbusHL(uint8_t* buf, uint8_t size, uint8_t highLow)
{
    if(highLow)
        return ((uint8_t)(GenCrc16Modbus(buf, size) & 0x00FF));
    return ((uint8_t)((GenCrc16Modbus(buf, size) >> 8) & 0xFF));
}

/**
 * @brief   Check CRC of Modbus 16
 * @param   buf Generate buf
 * @param   size Input source buf
 * @return  Check CRC success or fault
 * @note    Size include crc byte
 * @warning Buf size should not cross the boundary, otherwise it will get stuck
 */
uint8_t CheckCrc16Modbus(uint8_t* buf, uint8_t size)
{
    uint16_t tempCrc = GenCrc16Modbus(buf, size - 2);
    uint8_t CRC_L = (uint8_t)(tempCrc & 0x00FF);
    uint8_t CRC_H = (uint8_t)((tempCrc >> 8) & 0xFF);

    if((buf[size - 2] == CRC_L) && (buf[size - 1] == CRC_H))
        return 0;
    return 1;
}


#ifdef __DEBUG_ALGO_CRC_ATY
/**
 * @brief   Method of application
 */
void TestCrc16Modbus(void)
{
    volatile uint8_t checkResult = 0;
    const uint8_t tempA[12] = {0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0xB3, 0xC3};
    const uint8_t tempB[12] = {0x0A, 0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x02, 0x01};  // B0 E7

    checkResult = CheckCrc16Modbus(tempA, 12);
    printf("\r\bA check result: %d", checkResult);
    tempB[10] = (uint8_t)(GenCrc16Modbus(tempB, 10) & 0x00FF);
    tempB[11] = (uint8_t)((GenCrc16Modbus(tempB, 10) >> 8) & 0xFF);
    checkResult = CheckCrc16Modbus(tempB, 12);
#ifndef __CRC_CALC_ATY
    printf("\r\bB gen result calc normal(B0 E7): %02X %02X", tempB[10], tempB[11]);
#else
    printf("\r\bB gen result look-up table(B0 E7): %02X %02X", tempB[10], tempB[11]);
#endif /* __CRC_CALC_ATY */
    tempB[10] = GenCrc16ModbusHL(tempB, 10, 0);
    tempB[11] = GenCrc16ModbusHL(tempB, 10, 1);
    checkResult = CheckCrc16Modbus(tempB, 12);
    printf("\r\bB gen result calc with HL(E7 B0): %02X %02X", tempB[10], tempB[11]);
}
#endif /* __DEBUG_ALGO_CRC_ATY */


#endif  /* __ALGO_CRC_ATY_C */

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