crc8_nibble.cpp

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#if defined(ARDUINO_ARCH_AVR) || defined(ARDUINO_ARCH_SAMD)
  #include <avr/pgmspace.h>
#else
  #include <pgmspace.h>
#endif
#include "crc8_nibble.hpp" // header file converted by AceCRC
#include <stdlib.h>
#include <stdint.h>
 
namespace ace_crc {
namespace crc8_nibble {
 
 
 
static const crc_t crc_table[16] PROGMEM = {
    0x00, 0x07, 0x0e, 0x09, 0x1c, 0x1b, 0x12, 0x15, 0x38, 0x3f, 0x36, 0x31, 0x24, 0x23, 0x2a, 0x2d
};
 
 
crc_t crc_update(crc_t crc, const void *data, size_t data_len)
{
    const unsigned char *d = (const unsigned char *)data;
    uint8_t tbl_idx;
 
    while (data_len--) {
        tbl_idx = (crc >> 4) ^ (*d >> 4);
        crc = (pgm_read_byte(crc_table + (tbl_idx & 0x0f))) ^ (crc << 4);
        tbl_idx = (crc >> 4) ^ (*d >> 0);
        crc = (pgm_read_byte(crc_table + (tbl_idx & 0x0f))) ^ (crc << 4);
        d++;
    }
    return crc & 0xff;
}
 
} // crc8_nibble
} // ace_crc