/**
  @page FLASH_EraseProgram FLASH Erase and Program example
  
  @verbatim
  ******************** (C) COPYRIGHT 2014 STMicroelectronics *******************
  * @file    FLASH/FLASH_EraseProgram/readme.txt 
  * @author  MCD Application Team
  * @version V1.0.0
  * @date    18-June-2014
  * @brief  Description of the FLASH Erase and Program 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 

This example guides you through the different configuration steps by mean of HAL API
how to erase and program the internal FLASH memory embedded in the STM32L0xx from
STMicroelectronics. 

At the beginning of the main program the HAL_Init() function is called to reset 
all the peripherals, initialize the Flash interface and the systick.
Then the SystemClock_Config() function is used to configure the system clock (SYSCLK) 
to run with MSI clock at 2MHz.

After Reset, the Flash memory Program/Erase Controller is locked. A dedicated function
is used to enable the FLASH control register access.
Before programming the desired addresses, an erase operation is performed using 
the flash erase page feature. The erase procedure is done by filling the erase init 
structure giving the starting erase page and the number of pages to erase.
At this stage, all these pages will be erased one by one separately.

@note: if problem occurs on a page, erase will be stopped and faulty page will 
be returned to user (through variable 'PageError').

Once this operation is finished, page word programming operation will be performed 
in the FLASH memory. The written data is then read back and checked.

STM32L0538-DISCO board's LED can be used to monitor the transfer status:
 - LED3 is ON when there are no errors detected after data programing
 - LED3 is OFF when there is an issue during program procedure

@note Care must be taken when using HAL_Delay(), this function provides accurate
      delay (in milliseconds) based on variable incremented in SysTick ISR. This
      implies that if HAL_Delay() is called from a peripheral ISR process, then 
      the SysTick interrupt must have higher priority (numerically lower)
      than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
      To change the SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.

@note The application need to ensure that the SysTick time base is always set to 1 millisecond
      to have correct HAL operation.

@par Directory contents 

  - FLASH/FLASH_EraseProgram/Inc/stm32l0xx_hal_conf.h HAL Configuration file
  - FLASH/FLASH_EraseProgram/Inc/stm32l0xx_it.h       Header for stm32l0xx_it.c
  - FLASH/FLASH_EraseProgram/Inc/main.h               Main program header file
  - FLASH/FLASH_EraseProgram/Src/stm32l0xx_it.c       Interrupt handlers
  - FLASH/FLASH_EraseProgram/Src/main.c               Main program
  - FLASH/FLASH_EraseProgram/Src/system_stm32l0xx.c   STM32L0xx system clock configuration file


@par Hardware and Software environment  

  - This example runs on STM32L051xx, STM32L052xx, STM32L053xx STM32L062xx and 
    STM32L063xx device lines RevZ
    
  - This example has been tested with STM32L0538-DISCO RevB  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>
 */

