| 提交 | 用户 | age | ||
| 6a6261 | 1 | #include "crc.h" |
| Q | 2 | |
| 3 | ||
| 4 | uint16_t ComputeCrc( uint16_t crc, uint8_t dataByte, uint16_t polynomial ) | |
| 5 | { | |
| 6 | uint8_t i; | |
| 7 | ||
| 8 | for( i = 0; i < 8; i++ ) | |
| 9 | { | |
| 10 | if( ( ( ( crc & 0x8000 ) >> 8 ) ^ ( dataByte & 0x80 ) ) != 0 ) | |
| 11 | { | |
| 12 | crc <<= 1; // shift left once | |
| 13 | crc ^= polynomial; // XOR with polynomial | |
| 14 | } | |
| 15 | else | |
| 16 | { | |
| 17 | crc <<= 1; // shift left once | |
| 18 | } | |
| 19 | dataByte <<= 1; // Next data bit | |
| 20 | } | |
| 21 | return crc; | |
| 22 | } | |
| 23 | ||
| 24 | ||
| 25 | uint16_t RadioComputeCRC( uint8_t *buffer, uint8_t length, uint8_t crcType ) | |
| 26 | { | |
| 27 | uint8_t i = 0; | |
| 28 | uint16_t crc = 0; | |
| 29 | uint16_t polynomial = 0; | |
| 30 | ||
| 31 | polynomial = ( crcType == CRC_TYPE_IBM ) ? POLYNOMIAL_IBM : POLYNOMIAL_CCITT; | |
| 32 | crc = ( crcType == CRC_TYPE_IBM ) ? CRC_IBM_SEED : CRC_CCITT_SEED; | |
| 33 | for( i = 0; i < length; i++ ) | |
| 34 | { | |
| 35 | crc = ComputeCrc( crc, buffer[i], polynomial ); | |
| 36 | } | |
| 37 | if( crcType == CRC_TYPE_IBM ) | |
| 38 | { | |
| 39 | return crc; | |
| 40 | } | |
| 41 | else | |
| 42 | { | |
| 43 | return( ( uint16_t ) ( ~crc )); | |
| 44 | } | |
| 45 | } | |
| 46 | ||
| 47 | ||
