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2019-07-08 12:45:16 +01:00
/**
@page CRC_CalculateAndCheck CRC : CRC calculation and computed CRC value checking
@verbatim
******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
* @file Examples_LL/CRC/CRC_CalculateAndCheck/readme.txt
* @author MCD Application Team
* @brief Description of the CRC_CalculateAndCheck example.
******************************************************************************
*
* 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. Neither the name of STMicroelectronics nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS 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.
*
******************************************************************************
@endverbatim
@par Example Description
How to configure the CRC calculation unit to compute a CRC code for a given data
buffer, based on a fixed generator polynomial (default value 0x4C11DB7). The
peripheral initialization is done using LL unitary service functions for
optimization purposes (performance and size).
The CRC peripheral is configured to work with default polynomial value (32-bit long).
Normal representation of this polynomial value is :
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.
Generated CRC value is then 32 bits long
Example execution:
After startup from reset and system configuration, CRC configuration is performed (use of default Polynomial and initialisation values).
CRC code of a given data buffer is computed.
Data buffer length has been chosen as not an exact nb of u32 (32-bit words), in order to illustrate
use of offered API for feeding the calculator (u32, u16 or u8 inputs).
The calculated CRC code is stored in uwCRCValue variable.
Once calculated, CRC value (uwCRCValue) is compared to the CRC expected value (uwExpectedCRCValue),
and if both are equal, LED is turned On.
In case of errors, LED is blinking (1sec period).
@par Directory contents
- CRC/CRC_CalculateAndCheck/Inc/stm32f0xx_it.h Interrupt handlers header file
- CRC/CRC_CalculateAndCheck/Inc/main.h Header for main.c module
- CRC/CRC_CalculateAndCheck/Inc/stm32_assert.h Template file to include assert_failed function
- CRC/CRC_CalculateAndCheck/Src/stm32f0xx_it.c Interrupt handlers
- CRC/CRC_CalculateAndCheck/Src/main.c Main program
- CRC/CRC_CalculateAndCheck/Src/system_stm32f0xx.c STM32F0xx system source file
@par Hardware and Software environment
- This example runs on STM32F072xB devices.
- This example has been tested with STM32F072RB-Nucleo RevC board and can be
easily tailored to any other supported device and development board.
@par How to use it ?
In order to make the program work, you must do the following :
- Open your preferred toolchain
- Rebuild all files and load your image into target memory
- Run the example
* <h3><center>&copy; COPYRIGHT STMicroelectronics</center></h3>
*/