46 lines
994 B
C++
46 lines
994 B
C++
#include <inttypes.h>
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#ifdef __cplusplus
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extern "C" {
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#endif
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#define CRC8INIT 0x00
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#define CRC8POLY 0x18 //0X18 = X^8+X^5+X^4+X^0
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uint8_t crc8 ( uint8_t *data_in, uint16_t number_of_bytes_to_read )
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{
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uint8_t crc;
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uint16_t loop_count;
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uint8_t bit_counter;
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uint8_t data;
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uint8_t feedback_bit;
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crc = CRC8INIT;
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for (loop_count = 0; loop_count != number_of_bytes_to_read; loop_count++)
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{
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data = data_in[loop_count];
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bit_counter = 8;
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do {
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feedback_bit = (crc ^ data) & 0x01;
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if ( feedback_bit == 0x01 ) {
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crc = crc ^ CRC8POLY;
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}
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crc = (crc >> 1) & 0x7F;
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if ( feedback_bit == 0x01 ) {
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crc = crc | 0x80;
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}
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data = data >> 1;
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bit_counter--;
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} while (bit_counter > 0);
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}
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return crc;
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}
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}
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