tom dunigan / FastCRC

Port of teensy 3 FastCRC library, uses hardware CRC

Dependents:   fastCRCperf

Port of teensy 3 FastCRC library, uses hardware CRC on K64F. About 30 times faster than Arduino CRC (crc16.h).

https://github.com/FrankBoesing/FastCRC

teensy forum discussions on FastCRC https://forum.pjrc.com/threads/25699-Fast-CRC-library-(uses-the-built-in-crc-module-in-Teensy3)

crc16.h@1:1ce0f4ee7357, 2016-04-22 (annotated)

Committer:
manitou
Date:
Fri Apr 22 17:07:33 2016 +0000
Revision:
1:1ce0f4ee7357
Parent:
0:7343f324d853 
table-drive bug fix

Who changed what in which revision?

UserRevisionLine numberNew contents of line
manitou 0:7343f324d853 1 #ifndef _UTIL_CRC16_H_
manitou 0:7343f324d853 2 #define _UTIL_CRC16_H_
manitou 0:7343f324d853 3
manitou 0:7343f324d853 4 #include <stdint.h>
manitou 0:7343f324d853 5
manitou 0:7343f324d853 6 static inline uint16_t _crc16_update(uint16_t crc, uint8_t data) __attribute__((always_inline, unused));
manitou 0:7343f324d853 7 static inline uint16_t _crc16_update(uint16_t crc, uint8_t data)
manitou 0:7343f324d853 8 {
manitou 0:7343f324d853 9 unsigned int i;
manitou 0:7343f324d853 10
manitou 0:7343f324d853 11 crc ^= data;
manitou 0:7343f324d853 12 for (i = 0; i < 8; ++i) {
manitou 0:7343f324d853 13 if (crc & 1) {
manitou 0:7343f324d853 14 crc = (crc >> 1) ^ 0xA001;
manitou 0:7343f324d853 15 } else {
manitou 0:7343f324d853 16 crc = (crc >> 1);
manitou 0:7343f324d853 17 }
manitou 0:7343f324d853 18 }
manitou 0:7343f324d853 19 return crc;
manitou 0:7343f324d853 20 }
manitou 0:7343f324d853 21
manitou 0:7343f324d853 22 static inline uint16_t _crc_xmodem_update(uint16_t crc, uint8_t data) __attribute__((always_inline, unused));
manitou 0:7343f324d853 23 static inline uint16_t _crc_xmodem_update(uint16_t crc, uint8_t data)
manitou 0:7343f324d853 24 {
manitou 0:7343f324d853 25 unsigned int i;
manitou 0:7343f324d853 26
manitou 0:7343f324d853 27 crc = crc ^ ((uint16_t)data << 8);
manitou 0:7343f324d853 28 for (i=0; i<8; i++) {
manitou 0:7343f324d853 29 if (crc & 0x8000) {
manitou 0:7343f324d853 30 crc = (crc << 1) ^ 0x1021;
manitou 0:7343f324d853 31 } else {
manitou 0:7343f324d853 32 crc <<= 1;
manitou 0:7343f324d853 33 }
manitou 0:7343f324d853 34 }
manitou 0:7343f324d853 35 return crc;
manitou 0:7343f324d853 36 }
manitou 0:7343f324d853 37
manitou 0:7343f324d853 38 static inline uint16_t _crc_ccitt_update (uint16_t crc, uint8_t data) __attribute__((always_inline, unused));
manitou 0:7343f324d853 39 static inline uint16_t _crc_ccitt_update (uint16_t crc, uint8_t data)
manitou 0:7343f324d853 40 {
manitou 0:7343f324d853 41 data ^= (crc & 255);
manitou 0:7343f324d853 42 data ^= data << 4;
manitou 0:7343f324d853 43
manitou 0:7343f324d853 44 return ((((uint16_t)data << 8) | (crc >> 8)) ^ (uint8_t)(data >> 4)
manitou 0:7343f324d853 45 ^ ((uint16_t)data << 3));
manitou 0:7343f324d853 46 }
manitou 0:7343f324d853 47
manitou 0:7343f324d853 48 static inline uint8_t _crc_ibutton_update(uint8_t crc, uint8_t data) __attribute__((always_inline, unused));
manitou 0:7343f324d853 49 static inline uint8_t _crc_ibutton_update(uint8_t crc, uint8_t data)
manitou 0:7343f324d853 50 {
manitou 0:7343f324d853 51 unsigned int i;
manitou 0:7343f324d853 52
manitou 0:7343f324d853 53 crc = crc ^ data;
manitou 0:7343f324d853 54 for (i = 0; i < 8; i++) {
manitou 0:7343f324d853 55 if (crc & 0x01) {
manitou 0:7343f324d853 56 crc = (crc >> 1) ^ 0x8C;
manitou 0:7343f324d853 57 } else {
manitou 0:7343f324d853 58 crc >>= 1;
manitou 0:7343f324d853 59 }
manitou 0:7343f324d853 60 }
manitou 0:7343f324d853 61 return crc;
manitou 0:7343f324d853 62 }
manitou 0:7343f324d853 63
manitou 0:7343f324d853 64 #endif