/**
@page FreeRTOS_Mail FreeRTOS mail example
@verbatim
******************************************************************************
* @file FreeRTOS/FreeRTOS_Mail/readme.txt
* @author MCD Application Team
* @brief Description of the FreeRTOS Mail example.
******************************************************************************
*
* @attention
*
* Copyright (c) 2017 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
@endverbatim
@par Description
How to use mail queues with CMSIS RTOS API.
This example creates two threads that send and receive mail
the mail to send/receive is a structure that holds three variables (var1 and var2 are uint32, var3 is a uint8)
One thread acts as a producer and the other as the consumer.
The consumer is a higher priority than the producer and is set to block on mail receiving.
The Mail queue has space for one item. The producer allocates the mail and put it on the mail queue.
As soon as the producer posts a mail on the queue the consumer will unblock, preempt the producer,
get the mail and free it.
Add the following variables to LiveWatch, the three producer values must respectively remain equals to the three consumer values all the time:
- ConsumerValue1 must remain equal to ProducerValue1
- ConsumerValue2 must remain equal to ProducerValue2
- ConsumerValue3 must remain equal to ProducerValue3
LEDs can be used to monitor the example status:
- LED2(Green Led) should toggle when the example runs successfully.
- LED1(Red Led) toggle 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 HAL time base ISR. This implies that if HAL_Delay() is called from
a peripheral ISR process, then the HAL time base interrupt must have higher priority (numerically lower)
than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
To change the HAL time base interrupt priority you have to use HAL_NVIC_SetPriority() function.
@note The application need to ensure that the HAL time base is always set to 1 millisecond
to have correct HAL operation.
@note The FreeRTOS heap size configTOTAL_HEAP_SIZE defined in FreeRTOSConfig.h is set accordingly to the
OS resources memory requirements of the application with +10% margin and rounded to the upper Kbyte boundary.
For more details about FreeRTOS implementation on STM32Cube, please refer to UM1722 "Developing Applications
on STM32Cube with RTOS".
@par Keywords
RTOS, FreeRTOS, Threading, Mail, Queues,
@Note<74>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,
<20><><A0><A0><A0>then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
<0A><><A0><A0><A0><A0>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
<0A><><A0><A0><A0> It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
<0A><><A0><A0><A0><A0>In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
<0A><><A0><A0><A0><A0>Even though the user must manage the cache coherence for read accesses.
<0A><><A0><A0><A0><A0>Please refer to the AN4838 <20>Managing memory protection unit (MPU) in STM32 MCUs<55>
<0A><><A0><A0><A0><A0>Please refer to the AN4839 <20>Level 1 cache on STM32F7 Series<65>
@par Directory contents
- FreeRTOS/FreeRTOS_Mail/Src/main.c Main program
- FreeRTOS/FreeRTOS_Mail/Src/stm32f7xx_hal_timebase_tim.c HAL time base configuration
- FreeRTOS/FreeRTOS_Mail/Src/stm32f7xx_it.c Interrupt handlers
- FreeRTOS/FreeRTOS_Mail/Src/system_stm32f7xx.c STM32F7xx system clock configuration file
- FreeRTOS/FreeRTOS_Mail/Inc/main.h Main program header file
- FreeRTOS/FreeRTOS_Mail/Inc/stm32f7xx_hal_conf.h HAL Library Configuration file
- FreeRTOS/FreeRTOS_Mail/Inc/stm32f7xx_it.h Interrupt handlers header file
- FreeRTOS/FreeRTOS_Mail/Inc/FreeRTOSConfig.h FreeRTOS Configuration file
@par Hardware and Software environment
- This example runs on STM32F767xx/STM32F769xx/STM32F777xx/STM32F779xx devices.
- This example has been tested with STM32F769I-DISCO 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
*/
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