/**
@page RTC_Tamper RTC Tamper example
@verbatim
******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
* @file RTC/RTC_Tamper/readme.txt
* @author MCD Application Team
* @brief Description of the RTC Tamper 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 Example Description
This example guides you through the different configuration steps by means of the RTC
HAL API to write/read data to/from RTC Backup registers. It also demonstrates the tamper
detection feature.
At the beginning of the main program the HAL_Init() function is called to reset
all the peripherals, initialize the Flash interface and the systick.
Then the SystemClock_Config() function is used to configure the system
clock (SYSCLK) to run at 168 MHz.
The RTC peripheral configuration is ensured by the HAL_RTC_Init() function.
This later is calling the HAL_RTC_BspInit()function which core is implementing
the configuration of the needed RTC resources according to the used hardware (CLOCK,
PWR, RTC clock source and BackUp). You may update this function to change RTC configuration.
@note LSE oscillator clock is used as RTC clock source by default. LSE oscillator
clock usually delivered by a 32.768 kHz quartz.
The user can use also LSI as RTC clock source. The user uncomment the adequate
line on the main.h file.
@code
#define RTC_CLOCK_SOURCE_LSE
/* #define RTC_CLOCK_SOURCE_LSI */
@endcode
HAL_RTCEx_SetTamper_IT() function is then called to initialize the Tamper with
interrupt mode.
The associated firmware performs the following:
1. It configures the Tamper pin to be falling edge, and enables the Tamper
interrupt.
2. It writes the data to all RTC Backup data registers, then check whether the
data were correctly written. If yes, LED2 turns ON, otherwise LED3 turns ON.
3. Applying a low level on the TAMPER1 pin (PC.13) by pressing Tamper push button,
the RTC backup data registers are reset and the Tamper interrupt is generated
and LED1 turns ON.
The corresponding ISR then checks whether the RTC Backup data registers are cleared.
If yes LED4 Toggles, otherwise LED3 turns ON.
@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 needs to ensure that the SysTick time base is always set to 1 millisecond
to have correct HAL operation.
@par Keywords
System, RTC, Tamper, Reset, LSE, LSI
@par Directory contents
- RTC/RTC_Tamper/Inc/stm32f4xx_hal_conf.h HAL configuration file
- RTC/RTC_Tamper/Inc/stm32f4xx_it.h Interrupt handlers header file
- RTC/RTC_Tamper/Inc/main.h Main program header file
- RTC/RTC_Tamper/Src/stm32f4xx_it.c Interrupt handlers
- RTC/RTC_Tamper/Src/main.c Main program
- RTC/RTC_Tamper/Src/stm32f4xx_hal_msp.c HAL MSP module
- RTC/RTC_Tamper/Src/system_stm32f4xx.c STM32F4xx system clock configuration file
@par Hardware and Software environment
- This example runs on STM32F407xx/417xx devices.
- This example has been tested with STMicroelectronics STM324xG-EVAL RevC
evaluation boards 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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