#include "stdio.h"
typedef unsigned short uint16;
typedef unsigned char uint8;
//typedef char uint8;
typedef unsigned int uint32;
uint16 Crc_CalculateISOChecksum(uint8 *pt_start_address, uint32  length)
{
    uint8 C0, C1;
    uint8 data;
    uint32 i;
    uint8 ck1, ck2;

    /* Initial value */
    C0 = 0;
    C1 = 0;

    /* memories - 32bits wide*/
    for (i=0; i<length; i++)    /* nb_bytes has been verified */
    {
      data = pt_start_address[i];
      C0 = (C0 + data)%255;
      C1 = (C1 + C0)%255;
    }
    /* Calculate the intermediate ISO checksum value */
    ck1 = (unsigned char)(255-((C0+C1)%255));
    ck2 =  (unsigned char)(C1%255);
    if (ck1 == 0)
    {
      ck1 =255;// MASK_BYTE_LSB;
    }
    if (ck2 == 0)
    {
        ck2 = 255;//MASK_BYTE_LSB;
    }
    return ((((uint16)ck1)<<8) | ((uint16)ck2));
}

void main(void)
{
        unsigned short crc = 0;
//      unsigned char data[] = {0xAB,0xCD,0xEF,0x01};
        unsigned char data[] = {0x14,0x56,0xF8,0x9A,0x00,0x01};
        crc = Crc_CalculateISOChecksum(data,6);
        printf("%d %d %d \n",sizeof(uint8),sizeof(uint16),sizeof(uint32));
        printf("%x\n",crc);
}