STM32CubeF4

/**
  @page GPIO_InfiniteLedToggling GPIO example
  
  @verbatim
  ******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
  * @file    Examples_LL/GPIO/GPIO_InfiniteLedToggling/readme.txt 
  * @author  MCD Application Team
  * @brief   Description of the GPIO 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 configure and use GPIOs to toggle every 250 ms
the user LEDs available on the board. This example is based on the STM32F4xx
LL API. Peripheral initialization is done using LL unitary services functions
for optimization purpose (performance and size).

PA.05 IO (configured in output pushpull mode) toggles in a forever loop.
On NUCLEO-F411RE board this IO is connected to LED2.

In this example, HCLK is configured at 100 MHz.

@par Keywords

System, GPIO, Output, Alternate function, Push-pull, Toggle

@par Directory contents 

  - GPIO/GPIO_InfiniteLedToggling/Inc/stm32f4xx_it.h          Interrupt handlers header file
  - GPIO/GPIO_InfiniteLedToggling/Inc/main.h                  Header for main.c module
  - GPIO/GPIO_InfiniteLedToggling/Inc/stm32_assert.h          Template file to include assert_failed function
  - GPIO/GPIO_InfiniteLedToggling/Src/stm32f4xx_it.c          Interrupt handlers
  - GPIO/GPIO_InfiniteLedToggling/Src/main.c                  Main program
  - GPIO/GPIO_InfiniteLedToggling/Src/system_stm32f4xx.c      STM32F4xx system source file


@par Hardware and Software environment

  - This example runs on STM32F411xE devices.
    
  - This example has been tested with NUCLEO-F411RE 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>
 */