STM32CubeF7/Projects/STM32F767ZI-Nucleo/Examples_LL/UTILS/UTILS_ConfigureSystemClock

/**
  @page UTILS_ConfigureSystemClock UTILS example
  
  @verbatim
  ******************************************************************************
  * @file    Examples_LL/UTILS/UTILS_ConfigureSystemClock/readme.txt 
  * @author  MCD Application Team
  * @brief   Description of the UTILS example.
  ******************************************************************************
  *
  * Copyright (c) 2016 STMicroelectronics. All rights reserved.
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                       opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  @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 LED1 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 8 of PA_PORT) 
to check the requested frequency:
 - SYSCLK frequency with frequency value around @216MHz.

@par Keywords

Utils, system, Clock, HSI, PLL, flash latency, SYSCLK, frequencyn Oscilloscope

@Note If the user code size exceeds the DTCM-RAM size or starts from internal cacheable memories (SRAM1 and SRAM2),that is shared between several processors,
      then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
      The address and the size of cacheable buffers (shared between CPU and other masters)  must be properly updated to be aligned to cache line size (32 bytes).

@Note It is recommended to enable the cache and maintain its coherence, but depending on the use case
      It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
      In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
      Even though the user must manage the cache coherence for read accesses.
      Please refer to the AN4838 “Managing memory protection unit (MPU) in STM32 MCUs”
      Please refer to the AN4839 “Level 1 cache on STM32F7 Series”

@par Directory contents 

  - UTILS/UTILS_ConfigureSystemClock/Inc/stm32f7xx_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/stm32f7xx_it.c          Interrupt handlers
  - UTILS/UTILS_ConfigureSystemClock/Src/main.c                  Main program
  - UTILS/UTILS_ConfigureSystemClock/Src/system_stm32f7xx.c      STM32F7xx system source file


@par Hardware and Software environment

  - This example runs on STM32F767xx devices.
    
  - This example has been tested with NUCLEO-F767ZI 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>
 */