100 lines
4.3 KiB
Plaintext
100 lines
4.3 KiB
Plaintext
/**
|
||
@page HAL_TimeBase_TIM HAL Time base example
|
||
|
||
@verbatim
|
||
******************************************************************************
|
||
* @file HAL/HAL_TimeBase_TIM/readme.txt
|
||
* @author MCD Application Team
|
||
* @brief Description of the HAL time base example.
|
||
******************************************************************************
|
||
* @attention
|
||
*
|
||
* Copyright (c) 2016 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 Example Description
|
||
|
||
This example describes how to customize the HAL time base using a general
|
||
purpose timer instead of Systick as main source of time base.
|
||
|
||
In this example the used timer is TIM6.
|
||
|
||
Time base duration is kept unchanged: 1ms since PPP_TIMEOUT_VALUEs are defined
|
||
and handled in milliseconds basis.
|
||
|
||
The example brings, in user file, a new implementation of the following HAL weak functions:
|
||
|
||
HAL_InitTick()
|
||
HAL_SuspendTick()
|
||
HAL_ResumeTick()
|
||
|
||
This implementation will overwrite native implementation in stm32f7xx_hal.c
|
||
and so user functions will be invoked instead when called.
|
||
|
||
The following time base functions are kept as implemented natively:
|
||
|
||
HAL_IncTick()
|
||
HAL_Delay()
|
||
|
||
When user pushes the Tamper push-button, the Tick increment is suspended if it is already
|
||
enabled, else it will be resumed.
|
||
In an infinite loop, LED1 toggles spaced out over 1s delay.
|
||
|
||
@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
|
||
based on variable incremented in TIM6 ISR. This implies that if HAL_Delay() is called from
|
||
a peripheral ISR process, then the TIM6 interrupt must have higher priority (numerically lower)
|
||
than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
|
||
To change the TIM6 interrupt priority you have to use HAL_NVIC_SetPriority() function.
|
||
|
||
@note The application needs to ensure that the TIM6 time base is always set to 1 millisecond
|
||
to have correct HAL operation.
|
||
|
||
@par Keywords
|
||
|
||
System, General purpose Timer, Time base, HAL
|
||
|
||
@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><><EFBFBD><EFBFBD><EFBFBD>then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>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
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Even though the user must manage the cache coherence for read accesses.
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4838 <20>Managing memory protection unit (MPU) in STM32 MCUs<55>
|
||
<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4839 <20>Level 1 cache on STM32F7 Series<65>
|
||
|
||
@par Directory contents
|
||
|
||
- HAL/HAL_TimeBase_TIM/Inc/stm32f7xx_hal_conf.h HAL configuration file
|
||
- HAL/HAL_TimeBase_TIM/Inc/stm32f7xx_it.h Interrupt handlers header file
|
||
- HAL/HAL_TimeBase_TIM/Inc/stm32f7xx.h Header for main.c module
|
||
- HAL/HAL_TimeBase_TIM/Src/stm32f7xx_it.c Interrupt handlers
|
||
- HAL/HAL_TimeBase_TIM/Src/main.c Main program
|
||
- HAL/HAL_TimeBase_TIM/Src/stm32f7xx_hal_timebase_tim.c HAL time base functions
|
||
- HAL/HAL_TimeBase_TIM/Src/system_stm32f7xx.c STM32F7xx system source file
|
||
|
||
@par Hardware and Software environment
|
||
|
||
- This example runs on STM32F746xx devices
|
||
|
||
- This example has been tested with STMicroelectronics STM32746G-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
|
||
|
||
|
||
*/
|