src/lib/CRC/crc.cpp

   1 #include "crc.h"
   2
   3 GENERIC_CRC8::GENERIC_CRC8(uint8_t poly)
   4 {
   5     uint8_t crc;
   6
   7     for (uint16_t i = 0; i < crclen; i++)
   8     {
   9         crc = i;
  10         for (uint8_t j = 0; j < 8; j++)
  11         {
  12             crc = (crc << 1) ^ ((crc & 0x80) ? poly : 0);
  13         }
  14         crc8tab[i] = crc & 0xFF;
  15     }
  16 }
  17
  18 uint8_t ICACHE_RAM_ATTR GENERIC_CRC8::calc(const uint8_t data)
  19 {
  20     return crc8tab[data];
  21 }
  22
  23 uint8_t ICACHE_RAM_ATTR GENERIC_CRC8::calc(const uint8_t *data, uint8_t len, uint8_t crc)
  24 {
  25     while (len--)
  26     {
  27         crc = crc8tab[crc ^ *data++];
  28     }
  29     return crc;
  30 }
  31
  32 GENERIC_CRC14::GENERIC_CRC14(uint16_t poly)
  33 {
  34     uint16_t crc;
  35     for (uint16_t i = 0; i < crclen; i++)
  36     {
  37         crc = i << (14 - 8);
  38         for (uint8_t j = 0; j < 8; j++)
  39         {
  40             crc = (crc << 1) ^ ((crc & 0x2000) ? poly : 0);
  41         }
  42         crc14tab[i] = crc;
  43     }
  44 }
  45
  46 uint16_t ICACHE_RAM_ATTR GENERIC_CRC14::calc(uint8_t *data, uint8_t len, uint16_t crc)
  47 {
  48     while (len--)
  49     {
  50         crc = (crc << 8) ^ crc14tab[((crc >> 6) ^ (uint16_t) *data++) & 0x00FF];
  51     }
  52     return crc & 0x3FFF;
  53 }
  54
  55 uint16_t ICACHE_RAM_ATTR GENERIC_CRC14::calc(volatile uint8_t *data, uint8_t len, uint16_t crc)
  56 {
  57     while (len--)
  58     {
  59         crc = (crc << 8) ^ crc14tab[((crc >> 6) ^ (uint16_t) *data++) & 0x00FF];
  60     }
  61     return crc & 0x3FFF;
  62 }