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AP_Math: move crc8_dvb_s2 here and add additional crc8 functions

This commit is contained in:
Andy Piper 2020-04-30 20:35:18 +01:00 committed by Andrew Tridgell
parent d9f11c1a0a
commit d4c5b945b3
2 changed files with 22 additions and 0 deletions
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20
libraries/AP_Math/crc.cpp
View File

@ -90,6 +90,26 @@ uint8_t crc_crc8(const uint8_t *p, uint8_t len)
return crc & 0xFF;
}
// crc8 from betaflight
uint8_t crc8_dvb_s2(uint8_t crc, uint8_t a)
{
return crc8_dvb(crc, a, 0xD5);
}
// crc8 from betaflight
uint8_t crc8_dvb(uint8_t crc, uint8_t a, uint8_t seed)
{
crc ^= a;
for (uint8_t i = 0; i < 8; ++i) {
if (crc & 0x80) {
crc = (crc << 1) ^ seed;
} else {
crc = crc << 1;
}
}
return crc;
}
/*
xmodem CRC thanks to avr-liberty
https://github.com/dreamiurg/avr-liberty

2
libraries/AP_Math/crc.h
View File

@ -19,6 +19,8 @@
uint16_t crc_crc4(uint16_t *data);
uint8_t crc_crc8(const uint8_t *p, uint8_t len);
uint8_t crc8_dvb_s2(uint8_t crc, uint8_t a);
uint8_t crc8_dvb(uint8_t crc, uint8_t a, uint8_t seed);
uint16_t crc_xmodem_update(uint16_t crc, uint8_t data);
uint16_t crc_xmodem(const uint8_t *data, uint16_t len);
uint32_t crc_crc32(uint32_t crc, const uint8_t *buf, uint32_t size);