crc_xmodem.md

Libcrc API Reference

crc_xmodem( input_str, num_bytes );

Parameters

Parameter	Type	Description
input_str	const unsigned char *	The input byte buffer for which the CRC must be calculated
num_bytes	size_t	The number of characters in the input buffer

Return Value

Type	Description
uint16_t	The resulting CRC value

Description

The function crc_xmodem() calculates a 16 bit CRC value of an input byte buffer based on the CRC calculation algorithm used in the Xmodem protocol. The buffer length is provided as a parameter and the resulting CRC is returned as a return value by the function. The size of the buffer is limited to SIZE_MAX.

The Xmodem CRC calculation is a variant of the CCITT CRC calculation algorithm but with a different initialization parameter.

See Also

• crc_ccitt_1d0f();
• crc_ccitt_ffff();
• update_crc_ccitt();