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/**
* \file
*
* \brief 32-bit CRC header.
*
* Copyright (C) 2013-2015 Atmel Corporation. All rights reserved.
*
* \asf_license_start
*
* \page License
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* 3. The name of Atmel may not be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 4. This software may only be redistributed and used in connection with an
* Atmel microcontroller product.
*
* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
* EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* \asf_license_stop
*
*/
/*
* Support and FAQ: visit <a href="http://www.atmel.com/design-support/">Atmel Support</a>
*/
#ifndef CRC32_H
#define CRC32_H
#include <compiler.h>
/**
* \defgroup common_services_crc32 CRC-32 calculation service
*
* See \ref common_services_crc32_quickstart.
*
* This service enables the user to calculate 32-bit CRC using the polynomial
* defined in the IEEE 802.3 standard, with support for multiple data blocks
* of arbitrary sizes, and any alignment in memory.
*
* @{
*/
//! Type to contain 32-bit CRC.
typedef uint32_t crc32_t;
#ifdef __cplusplus
extern "C" {
#endif
enum status_code crc32_recalculate(const void *data, size_t length, crc32_t *crc);
#ifdef __cplusplus
}
#endif
/**
* \brief Calculate 32-bit CRC for initial block
*
* This function calculates the CRC for the specified data block, which may be
* first of an arbitrary number of blocks.
*
* The actual calculation is done in \ref crc32_recalculate(), while this
* function just sets up the initial CRC value.
*
* \param[in] data Address of data.
* \param[in] length Length of data.
* \param[out] crc Address of variable to store the calculated CRC in.
*
* \return Status of calculation.
* \retval STATUS_OK if calculation succeeded.
* \retval <other> if calculation failed somehow.
*
* \note To calculate the CRC of multiple blocks, use this function first, then
* \ref crc32_recalculate() for the following blocks.
*/
static inline enum status_code crc32_calculate(const void *data, size_t length,
crc32_t *crc)
{
*crc = 0;
return crc32_recalculate(data, length, crc);
}
/** @} */
/**
* \page common_services_crc32_quickstart Quick Start Guide for CRC-32
*
* To use this service, the user must supply a \ref crc32_t "container" variable
* for the CRC and call \ref crc32_calculate() with the parameters for the first
* block in the dataset. For subsequent blocks, \ref crc32_recalculate() must be
* used.
*
* \note The user may also initialize the container with a known CRC value and
* use that as the "seed" for \ref crc32_recalculate().
*
*
* \section common_services_crc32_quickstart_code Example Code
*
\code
uint8_t block1[10] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
uint8_t block2[6] = {0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f};
crc32_t my_crc;
crc32_calculate(block1, sizeof(block1), &my_crc);
crc32_recalculate(block2, sizeof(block2), &my_crc);
\endcode
*
*/
#endif // CRC32_H
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