OWIcrc.h File Reference

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Defines
#define	OWI_CRC_OK   0x00
	CRC check succeded.
#define	OWI_CRC_ERROR   0x01
	CRC check failed.
Functions
unsigned char	OWI_ComputeCRC8 (unsigned char inData, unsigned char seed)
	Compute the CRC8 value of a data set.
unsigned int	OWI_ComputeCRC16 (unsigned char inData, unsigned int seed)
	Compute the CRC16 value of a data set.
unsigned char	OWI_CheckRomCRC (unsigned char *romValue)
	Calculate and check the CRC of a 64 bit ROM identifier.

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Detailed Description

Atmel Corporation

• File: OWIcrc.h
• Compiler: IAR EWAAVR 3.20a
• Support mail: avr@atmel.com

• Supported devices: All AVRs.

• Application Note: AVR318 - Dallas 1-Wire(R) master.

• Description: Header file for OWIUtils.c

Revision

1.7

Date

Thursday, August 19, 2004 14:27:16 UTC

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Define Documentation

#define OWI_CRC_ERROR   0x01

CRC check failed.

#define OWI_CRC_OK   0x00

CRC check succeded.

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Function Documentation

unsigned char OWI_CheckRomCRC

(

unsigned char *

romValue

)

Calculate and check the CRC of a 64 bit ROM identifier.

This function computes the CRC8 value of the first 56 bits of a 64 bit identifier. It then checks the calculated value against the CRC value stored in ROM.

Parameters:

romvalue

A pointer to an array holding a 64 bit identifier.

Return values:

	OWI_CRC_OK	The CRC's matched.
	OWI_CRC_ERROR	There was a discrepancy between the calculated and the stored CRC.

unsigned int OWI_ComputeCRC16	(	unsigned char	inData,
		unsigned int	seed
	)

Compute the CRC16 value of a data set.

This function will compute the CRC16 of inData using seed as inital value for the CRC.

Parameters:

	inData	One byte of data to compute CRC from.
	seed	The starting value of the CRC.

Returns:

The CRC16 of inData with seed as initial value.

Note:

Setting seed to 0 computes the crc16 of the inData.

Constantly passing the return value of this function As the seed argument computes the CRC16 value of a longer string of data.

unsigned char OWI_ComputeCRC8	(	unsigned char	inData,
		unsigned char	seed
	)

Compute the CRC8 value of a data set.

This function will compute the CRC8 or DOW-CRC of inData using seed as inital value for the CRC.

Parameters:

	inData	One byte of data to compute CRC from.
	seed	The starting value of the CRC.

Returns:

The CRC8 of inData with seed as initial value.

Note:

Setting seed to 0 computes the crc8 of the inData.

Constantly passing the return value of this function As the seed argument computes the CRC8 value of a longer string of data.