97 lines
4.4 KiB
Plaintext
97 lines
4.4 KiB
Plaintext
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/**
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@page HAL_TimeBase HAL Time base example
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@verbatim
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******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
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* @file HAL/HAL_TimeBase/readme.txt
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* @author MCD Application Team
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* @brief Description of the HAL time base example.
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******************************************************************************
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. Neither the name of STMicroelectronics nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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This example describes how to customize the HAL time base using a general
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purpose timer(TIM6) instead of Systick as main source of time base.
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Time base duration is kept unchanged: 1ms since PPP_TIMEOUT_VALUEs are defined
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and handled in milliseconds basis.
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The example brings, in user file, a new implementation of the following HAL weak functions:
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HAL_InitTick()
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HAL_SuspendTick()
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HAL_ResumeTick()
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This implementation will overwrite native implementation from stm32f4xx_hal.c
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and so user functions will be invoked instead when called.
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The following time base functions are kept as implemented natively:
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HAL_IncTick()
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HAL_Delay()
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HAL_IncTick()
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When user pushes the User push-button, the Tick increment is suspended if it is already
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enabled, else it will be resumed.
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In an infinite loop, LED1 toggles spaced out over 1s delay.
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@note Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds)
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based on variable incremented in TIM6 ISR. This implies that if HAL_Delay() is called from
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a peripheral ISR process, then the TIM6 interrupt must have higher priority (numerically lower)
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than the peripheral interrupt. Otherwise the caller ISR process will be blocked.
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To change the TIM6 interrupt priority you have to use HAL_NVIC_SetPriority() function.
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@note The application need to ensure that the TIM6 time base is always set to 1 millisecond
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to have correct HAL operation.
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@par Directory contents
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- HAL/HAL_TimeBase/Inc/stm32f4xx_hal_conf.h HAL configuration file
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- HAL/HAL_TimeBase/Inc/stm32f4xx_it.h Interrupt handlers header file
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- HAL/HAL_TimeBase/Inc/stm32f4xx.h Header for main.c module
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- HAL/HAL_TimeBase/Src/stm32f4xx_it.c Interrupt handlers
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- HAL/HAL_TimeBase/Src/main.c Main program
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- HAL/HAL_TimeBase/Src/system_stm32f4xx.c STM32F4xx system source file
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@par Hardware and Software environment
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- This example runs on STM32F446xx devices
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- This example has been tested with STMicroelectronics STM32446E-EVAL board and can be
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easily tailored to any other supported device and development board.
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@par How to use it ?
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In order to make the program work, you must do the following :
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- Open your preferred toolchain
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- Rebuild all files and load your image into target memory
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- Run the example
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* <h3><center>© COPYRIGHT STMicroelectronics</center></h3>
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*/
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