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111 lines
4.9 KiB
Plaintext
111 lines
4.9 KiB
Plaintext
/**
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@page RTC_Alarm RTC Alarm Example
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@verbatim
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******************************************************************************
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* @file RTC/RTC_Alarm/readme.txt
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* @author MCD Application Team
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* @brief Description of the RTC Alarm example.
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******************************************************************************
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* @attention
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*
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* Copyright (c) 2016 STMicroelectronics.
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* All rights reserved.
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*
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* This software is licensed under terms that can be found in the LICENSE file
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* in the root directory of this software component.
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* If no LICENSE file comes with this software, it is provided AS-IS.
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*
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******************************************************************************
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@endverbatim
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@par Example Description
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Configuration and generation of an RTC alarm using the RTC HAL API.
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At the beginning of the main program the HAL_Init() function is called to reset
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all the peripherals, initialize the Flash interface and the systick.
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Then the SystemClock_Config() function is used to configure the system
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clock (SYSCLK) to run at 216 MHz.
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The RTC peripheral configuration is ensured by the HAL_RTC_Init() function.
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This later is calling the HAL_RTC_MspInit()function which core is implementing
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the configuration of the needed RTC resources according to the used hardware (CLOCK,
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PWR, RTC clock source and BackUp). You may update this function to change RTC configuration.
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@note LSE oscillator clock is used as RTC clock source by default.
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The user can use also LSI as RTC clock source. The user uncomment the adequate
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line on the main.h file.
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@code
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#define RTC_CLOCK_SOURCE_LSE
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/* #define RTC_CLOCK_SOURCE_LSI */
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@endcode
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LSI oscillator clock is delivered by a 32 kHz RC.
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LSE (when available on board) is delivered by a 32.768 kHz crystal.
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HAL_RTC_SetDate() and HAL_RTC_SetTime() functions are called to initialize the
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time and the date.
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HAL_RTC_SetAlarm_IT() function is then called to initialize the Alarm feature with
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interrupt mode.
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In this example, the Time is set to 02:20:00 and the Alarm must be generated after
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30 seconds on 02:20:30.
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LED6 is turned ON when the RTC Alarm is generated correctly.
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The current time is updated and displayed on the debugger in aShowTime variable.
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In case of error, LED5 is toggled with a period of one second.
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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 SysTick ISR. This implies that if HAL_Delay() is called from
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a peripheral ISR process, then the SysTick 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 SysTick interrupt priority you have to use HAL_NVIC_SetPriority() function.
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@note The application need to ensure that the SysTick time base is always set to 1 millisecond
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to have correct HAL operation.
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@par Keywords
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System, RTC, Alarm, wakeup timer, Backup domain, Counter, LSE, LSI
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@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,
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<20><><EFBFBD><EFBFBD><EFBFBD>then it is highly recommended to enable the CPU cache and maintain its coherence at application level.
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<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).
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@Note It is recommended to enable the cache and maintain its coherence, but depending on the use case
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> It is also possible to configure the MPU as "Write through", to guarantee the write access coherence.
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>In that case, the MPU must be configured as Cacheable/Bufferable/Not Shareable.
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Even though the user must manage the cache coherence for read accesses.
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4838 <20>Managing memory protection unit (MPU) in STM32 MCUs<55>
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<EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Please refer to the AN4839 <20>Level 1 cache on STM32F7 Series<65>
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@par Directory contents
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- RTC/RTC_Alarm/Inc/stm32f7xx_hal_conf.h HAL configuration file
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- RTC/RTC_Alarm/Inc/stm32f7xx_it.h Interrupt handlers header file
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- RTC/RTC_Alarm/Inc/main.h Header for main.c module
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- RTC/RTC_Alarm/Src/stm32f7xx_it.c Interrupt handlers
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- RTC/RTC_Alarm/Src/main.c Main program
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- RTC/RTC_Alarm/Src/stm32f7xx_hal_msp.c HAL MSP module
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- RTC/RTC_Alarm/Src/system_stm32f7xx.c STM32F7xx system source file
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@par Hardware and Software environment
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- This example runs on STM32F722xx/STM32F723xx/STM32F732xx/STM32F733xx devices.
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- This example has been tested with STMicroelectronics STM32F723E-DISCOVERY
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board and can be easily tailored to any other supported device
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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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*/
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