iOBC Checksum API¶

group iOBC-Checksum

Functions

void checksum_prepare_LUTCRC8(uint8_t polynomial, uint8_t *LUT)¶

Generate a LUT for CRC 8 calculations with a certain polynomial.

Parameters

polynomial – [in] 8-bit CRC polynomial to be used
LUT – [out] Pointer to memory block where LUT can be stored, needs to be at least 256 * sizeof(uint8_t)

uint8_t checksum_calculate_CRC8LUT(const uint8_t *data, unsigned int length, const uint8_t *LUT, uint8_t start_remainder, bool endofdata)¶

Calculates a CRC 8 checksum according to CRC-8 CCITT, using a LUT.

Parameters

data – [in] Pointer to data to calculate the checksum for.
length – [in] Length of the data in bytes.
LUT – [in] Pointer to LUT to use for CRC calculations, prepared using checksum_prepareLUTCRC8()
start_remainder – [in] Remainder to start CRC calculation with
endofdata – [in] Indicates whether this is the end of larger datablock (TRUE) or not yet (FALSE)

Returns

uint8_t 8-bit CRC checksum.

uint8_t checksum_calculate_CRC8(const uint8_t *data, unsigned int length, uint8_t polynomial, uint8_t start_remainder, bool endofdata)¶

Calculates a CRC 8 checksum according to CRC-8 CCITT, using bitwise calculation.

Parameters

data – [in] Pointer to data to calculate the checksum for.
length – [in] Length of the data in bytes.
polynomial – [in] 8-bit CRC polynomial to be used.
start_remainder – [in] Remainder to start CRC calculation with
endofdata – [in] Indicates whether this is the end of larger datablock (TRUE) or not yet (FALSE)

Returns

uint8_t 8-bit CRC checksum.

uint8_t supervisor_calculate_CRC(const uint8_t *data, unsigned int length)¶

Calculates a CRC checksum according to the algorithm used in the iOBC supervisor.

Parameters

Returns

uint8_t 8-bit CRC checksum.