/**
  @page UTILS_ConfigureSystemClock UTILS example
  
  @verbatim
  ******************** (C) COPYRIGHT 2016 STMicroelectronics *******************
  * @file    Examples_LL/UTILS/UTILS_ConfigureSystemClock/readme.txt 
  * @author  MCD Application Team
  * @version V1.0.0
  * @date    14-April-2017
  * @brief   Description of the UTILS 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 describes how to use UTILS LL API to configure the system clock using PLL with HSI as source
clock. The user application just needs to calculate PLL parameters using STM32CubeMX and call the UTILS LL
API.

System starts with clock used after reset.
Then, a system clock switch is done to PLL with HSI as PLL clock source. Automatically, FLASH latency
is tuned according to system constraints described in the reference manual.

User can easily set its own PLL parameters in changing global variable used to store them.

A LED2 toggle of 1sec provides this information that system is well configured to requested frequency.  

Anyway, signal on PA.08 can be monitored with an oscilloscope (in connecting PA.08 to pin 23 of CN10) 
to check the requested frequency:
 - SYSCLK frequency with frequency value around @64MHz.

@par Directory contents 

  - UTILS/UTILS_ConfigureSystemClock/Inc/stm32f1xx_it.h          Interrupt handlers header file
  - UTILS/UTILS_ConfigureSystemClock/Inc/main.h                  Header for main.c module
  - UTILS/UTILS_ConfigureSystemClock/Inc/stm32_assert.h          Template file to include assert_failed function
  - UTILS/UTILS_ConfigureSystemClock/Src/stm32f1xx_it.c          Interrupt handlers
  - UTILS/UTILS_ConfigureSystemClock/Src/main.c                  Main program
  - UTILS/UTILS_ConfigureSystemClock/Src/system_stm32f1xx.c      STM32F1xx system source file


@par Hardware and Software environment

  - This example runs on STM32F103xB devices.
    
  - This example has been tested with STM32F103RB-Nucleo 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>
 */
