Lightweight CRC16 checksum algorithms. More...

Detailed Description

Lightweight CRC16 checksum algorithms.

This CRC16 implementation does not use pre-calculated lookup tables and is thus very lightweight (memory-wise), but as a caveat slower (about factor 8) than the version with pre-calculated lookup tables.

Additionally compared to CRC16-CCITT this is a generalized implementation. One can easily exchange generator polynomials and starting seeds.

Files
file	ucrc16.h
	ucrc16 definitions

Functions
uint16_t	ucrc16_calc_be (const uint8_t *buf, size_t len, uint16_t poly, uint16_t seed)
	Calculate CRC16 (big-endian version)

uint16_t	ucrc16_calc_le (const uint8_t *buf, size_t len, uint16_t poly, uint16_t seed)
	Calculate CRC16 (little-endian version)

#define	UCRC16_CCITT_POLY_BE (0x1021)
	Various generator polynomials.

#define	UCRC16_CCITT_POLY_LE (0x8408)
	CRC16-CCITT polynomial (little-endian)

Macro Definition Documentation

◆ UCRC16_CCITT_POLY_BE

#define UCRC16_CCITT_POLY_BE (0x1021)

Various generator polynomials.

CRC16-CCITT polynomial (big-endian)

Definition at line 43 of file ucrc16.h.

◆ UCRC16_CCITT_POLY_LE

#define UCRC16_CCITT_POLY_LE (0x8408)

CRC16-CCITT polynomial (little-endian)

Definition at line 44 of file ucrc16.h.

Function Documentation

◆ ucrc16_calc_be()

uint16_t ucrc16_calc_be	(	const uint8_t *	buf,
		size_t	len,
		uint16_t	poly,
		uint16_t	seed
	)

Calculate CRC16 (big-endian version)

Parameters

[in]	buf	Start of memory are to checksum
[in]	len	Number of bytes in `buf` to calculate checksum for
[in]	poly	The generator polynomial for the checksum
[in]	seed	The seed (starting value) for the checksum

Returns: Checksum of the specified memory area based on seed and poly

Note: The return value is not the complement of the sum but the sum itself

◆ ucrc16_calc_le()

uint16_t ucrc16_calc_le	(	const uint8_t *	buf,
		size_t	len,
		uint16_t	poly,
		uint16_t	seed
	)

Calculate CRC16 (little-endian version)