Description

32-bit CRC (Cyclic Redundancy Check) calculator for checksums.

File(s):

A CRC is an error-detecting code that is used for data integrity checks.

See also: http://en.wikipedia.org/wiki/Cyclic_redundancy_check; https://crccalc.com

Note that the polynomial value is bit reversed and a right shift operator is used during the calculation.

Macros
#define	PX_CRC32_POLYNOMIAL 0xedb88320
	The generator polynomial CRC32 (reversed representation): x^32 + x^26 + x^23 + x^22 + x^16. More...

#define	PX_CRC32_INIT_VAL 0xffffffff
	Initial CRC value. More...

#define	PX_CRC32_RAM_TABLE 0
	Generate table in RAM to speed up CRC calculation. More...

#define	PX_CRC32_ROM_TABLE 0
	Use table in ROM to speed up CRC calculation. More...

Functions
void	px_crc32_init (void)
	Initialise 32-bit CRC calculator. More...

uint32_t	px_crc32_update_u8 (uint32_t crc, uint8_t data)
	Calculate the 32-bit CRC over one byte. More...

uint32_t	px_crc32_update_data (uint32_t crc, const void *data, size_t nr_of_bytes)
	Calculate the 32-bit CRC over a number of bytes. More...

Macro Definition Documentation

◆ PX_CRC32_POLYNOMIAL

#define PX_CRC32_POLYNOMIAL 0xedb88320

The generator polynomial CRC32 (reversed representation): x^32 + x^26 + x^23 + x^22 + x^16.

x^12 + x^11 + x^10 + x^8 + x^7 + x^5 + x^4 + x^2 + x + 1

Definition at line 69 of file px_crc32.h.

◆ PX_CRC32_INIT_VAL

#define PX_CRC32_INIT_VAL 0xffffffff

Initial CRC value.

Definition at line 71 of file px_crc32.h.

◆ PX_CRC32_RAM_TABLE

#define PX_CRC32_RAM_TABLE 0

Generate table in RAM to speed up CRC calculation.

Definition at line 34 of file px_crc32_cfg_template.h.

◆ PX_CRC32_ROM_TABLE

#define PX_CRC32_ROM_TABLE 0

Use table in ROM to speed up CRC calculation.

Definition at line 37 of file px_crc32_cfg_template.h.

Function Documentation

◆ px_crc32_init()

void px_crc32_init ( void )

Initialise 32-bit CRC calculator.

This function will initialise the table in RAM with constants to speed up CRC calculation. For other options it does nothing.

Definition at line 89 of file px_crc32.c.

◆ px_crc32_update_u8()

uint32_t px_crc32_update_u8	(	uint32_t	crc,
		uint8_t	data
	)

Calculate the 32-bit CRC over one byte.

Parameters

crc	The initial CRC to start the calculation with
data	The value to calculate the CRC over

Returns: uint32_t The resultant CRC

Definition at line 117 of file px_crc32.c.

◆ px_crc32_update_data()

uint32_t px_crc32_update_data	(	uint32_t	crc,
		const void *	data,
		size_t	nr_of_bytes
	)

Calculate the 32-bit CRC over a number of bytes.