1 | /*
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2 | * crc16.c
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3 | *
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4 | * Created: 19.11.2016 09:24:16
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5 | * Author: Admin
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6 | */
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7 |
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8 | #include "crc16.h"
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9 |
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10 | unsigned int crc16;
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11 |
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12 |
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13 | void InitCRC(void) {
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14 | crc16 = 0xffff;
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15 | }
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16 |
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17 |
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18 | unsigned int CalcCRC(unsigned char data) {
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19 | unsigned char bitCount;
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20 | unsigned char PolynomFlag;
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21 | for (bitCount = 0; bitCount <8; bitCount++) {
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22 | PolynomFlag = (crc16 &0x8000) != 0;
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23 | crc16 <<= 1;
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24 | if (data &0x80) {
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25 | crc16 |= 1;
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26 | }
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27 | data <<= 1;
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28 | if (PolynomFlag)
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29 | crc16 ^= CRC16_POLYNOM;
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30 | }
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31 |
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32 | return crc16;
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33 | }
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34 |
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35 | uCRC16_t CalcCRCBuffer(unsigned char *data, unsigned int length)
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36 | {
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37 | uCRC16_t result;
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38 |
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39 | InitCRC();
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40 | for(int i =0; i<length; i++)
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41 | {
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42 | result.iCRC16 = CalcCRC(*data++);
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43 | }
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44 | result.iCRC16 = CalcCRC(0);
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45 | result.iCRC16 = CalcCRC(0);
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46 |
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47 | return result;
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48 | }
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49 |
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50 | bool CheckCRC(unsigned char *data, unsigned int length)
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51 | {
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52 | bool result = false;
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53 | uCRC16_t crc;
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54 | int a;
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55 | crc = CalcCRCBuffer(data,length);
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56 | if((crc.cCRC16[CRC_LO]== *(data +length +1)) &&(crc.cCRC16[CRC_HI]== *(data +length)))
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57 | {
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58 | a = 1;
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59 | result = true;
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60 | }
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61 |
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62 | return result;
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63 |
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64 | }
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