fork download
copy 
  1. #include <stdio.h>
  2.  
  3. unsigned short int pec15Table[256];
  4. unsigned short int CRC15_POLY = 0x4599;
  5. void init_PEC15_Table();
  6. unsigned short int pec15 (unsigned char *data , int len);
  7. unsigned char Tx_data[8]={0};
  8. unsigned short int pec;
  9.  
  10.  
  11. int main(void) 
  12. {
  13. 	int i;
  14. 	Tx_data[0] = 0xFF;
  15. 	Tx_data[1] = 0xFF;
  16. 	Tx_data[2] = 0xFF;
  17. 	Tx_data[3] = 0xFF;
  18. 	Tx_data[4] = 0xFF;
  19. 	Tx_data[5] = 0xFF;
  20.  
  21.     init_PEC15_Table();
  22. 	for(i=0;i<256;i++)
  23. 	{
  24. 	/* printf("\t%d",pec15Table[i]);*/
  25. 	}
  26. 	pec= pec15(&Tx_data[0],6);
  27. 	printf("\t%d",pec);
  28. 	return 0;
  29. }
  30.  
  31.  
  32. void init_PEC15_Table()
  33. {
  34. int i,bit ;
  35. unsigned short int remainder;
  36. for ( i = 0; i < 256; i++)
  37. {
  38. 	remainder = i << 7;
  39.  
  40. 	for (bit = 8; bit > 0; --bit)
  41. 	{
  42. 		if (remainder & 0x4000)
  43. 		{
  44. 			remainder = ((remainder << 1));
  45. 			remainder = (remainder ^ CRC15_POLY);
  46. 		}
  47. 		else
  48. 		{
  49. 			remainder = ((remainder << 1));
  50. 		}
  51. 	}
  52.  
  53. 	pec15Table[i] = remainder&0xFFFF;
  54.  
  55. }
  56. }
  57. unsigned short int pec15 (unsigned char *data , int len)
  58. {
  59. 	unsigned int i, remainder,address;
  60. 	remainder = 16;//PEC seed
  61. 	for (i = 0; i < len; i++)
  62. 	{
  63. 		address = ((remainder >> 7) ^ data[i]) & 0xff;//calculate PEC table address
  64. 		remainder = (remainder << 8 ) ^ pec15Table[address];
  65. 	}
  66. 	return (remainder*2);//The CRC15 has a 0 in the LSB so the final value must be multiplied by 2
  67. }
  68.  
Success #stdin #stdout 0.01s 5284KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
	26188
https://ideone.com/FCFjzZ
language:
C (gcc 8.3)
created:
4 days ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!