/**
  @page FreeRTOS_Mutexes FreeRTOS Mutexes example
 
  @verbatim
  ******************** (C) COPYRIGHT 2014 STMicroelectronics *******************
  * @file    FreeRTOS/FreeRTOS_Mutexes/readme.txt
  * @author  MCD Application Team
  * @version V1.1.0
  * @date    18-June-2014
  * @brief   Description of the FreeRTOS Mutexes 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 Description

This directory contains a set of source files that implement an example
that uses mutexes with CMSIS RTOS API 

This example creates three threads, with different priorities, that access the 
same mutex, as described below:

MutexHighPriorityThread() has the highest priority so executes 
first and grabs the mutex and sleeps for a short period to let the lower 
priority threads execute.  When it has completed its demo functionality
it gives the mutex back before suspending itself. 
 
MutexMeduimPriorityThread() attempts to access the mutex by performing
a blocking 'wait'.  This thread blocks when the mutex is already taken 
by the high priority thread. It does not unblock until the highest 
priority thread  has released the mutex, and it does not actually run until 
the highest priority thread has suspended itself.
When it eventually does obtain the mutex all it does is give the mutex back
prior to also suspending itself.  At this point both the high and medium
priority threads are suspended.

MutexLowPriorityThread() runs at the idle priority.  It spins round
a tight loop attempting to obtain the mutex with a non-blocking call.  As
the lowest priority thread it will not successfully obtain the mutex until
both high and medium priority threads are suspended.  Once it eventually 
does obtain the mutex it first resume both suspended threads prior to giving
the mutex back - resulting in the low priority thread temporarily inheriting
the highest thread priority.       

Add the following variables to LiveWatch, these variables must remain equals all the time:
 - HighPriorityThreadCycles
 - MediumPriorityThreadCycles
 - LowPriorityThreadCycles
 
STM32 Nucleo board's LEDs can be used to monitor the example status:
  - LED2 is ON when any error occurs.


@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.

For more details about FreeRTOS implementation on STM32Cube, please refer to UM1722 "Developing Applications 
on STM32Cube with RTOS".


@par Directory contents

    - FreeRTOS/FreeRTOS_Mutexes/Src/main.c                Main program
    - FreeRTOS/FreeRTOS_Mutexes/Src/stm32l0xx_it.c        Interrupt handlers
    - FreeRTOS/FreeRTOS_Mutexes/Src/system_stm32l0xx.c    STM32L0xx system clock configuration file
    - FreeRTOS/FreeRTOS_Mutexes/Inc/main.h                Main program header file
    - FreeRTOS/FreeRTOS_Mutexes/Inc/stm32l0xx_hal_conf.h  HAL Library Configuration file
    - FreeRTOS/FreeRTOS_Mutexes/Inc/stm32l0xx_it.h        Interrupt handlers header file
    - FreeRTOS/FreeRTOS_Mutexes/Inc/FreeRTOSConfig.h      FreeRTOS 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 STM32L053R8-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>
 */
