122 lines
6.0 KiB
Plaintext
122 lines
6.0 KiB
Plaintext
/**
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@page PWR_Standby PWR_STANDBY example
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@verbatim
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******************** (C) COPYRIGHT 2017 STMicroelectronics *******************
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* @file PWR/PWR_STANDBY/readme.txt
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* @author MCD Application Team
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* @brief Description of the PWR STANDBY 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 shows how to enters the system to STANDBY mode and wake-up from this mode
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using external RESET, RTC Alarm A or WKUP pin.
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In the associated software, the system clock is set to 180 MHz, an EXTI line
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is configured to generate an interrupt on falling edge and the SysTick is programmed
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to generate an interrupt each 250 ms. In the SysTick interrupt handler, the LED1 is
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toggled, this is used to indicate whether the MCU is in STANDBY or RUN mode.
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When a falling edge is detected on the EXTI line an interrupt is generated. In the
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EXTI handler routine the RTC is configured to generate an Alarm event in 5 second
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then the system enters STANDBY mode causing the LED1 to stop toggling.
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A rising edge on WKUP pin or an external RESET will wake-up the system from
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STANDBY. If within 5 second neither rising edge on WKUP pin nor external RESET
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are generated, the RTC Alarm A will wake-up the system.
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After wake-up from STANDBY mode, program execution restarts in the same way as after
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a RESET, the RTC configuration (clock source, prescaler,...) is kept and LED1 restarts
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toggling. As result there is no need to configure the RTC.
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Two LEDs LED1 and LED2 are used to monitor the system state as following:
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- LED2 ON: configuration failed (system will go to an infinite loop)
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- LED1 toggling: system in RUN mode
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- LED1 OFF: system in STANDBY mode
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These Steps are repeated in an infinite loop.
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@note To measure the current consumption in STANDBY mode, please refer to
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@subpage PWR_CurrentConsumption example.
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@note This example can not be used in DEBUG mode, this is due to the fact
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that the Cortex-M4 core is no longer clocked during low power mode
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so debugging features are disabled
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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 needs 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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@note Care must be taken when HAL_RCCEx_PeriphCLKConfig() is used to select the RTC clock source; in this
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case the Backup domain will be reset in order to modify the RTC Clock source, as consequence RTC
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registers (including the backup registers) and RCC_BDCR register are set to their reset values.
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@par Keywords
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Power, PWR, Standby mode, Interrupt, EXTI, Wakeup, Low Power, External reset
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@par Directory contents
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- PWR/PWR_STANDBY/Inc/stm32f4xx_hal_conf.h HAL configuration file
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- PWR/PWR_STANDBY/Inc/stm32f4xx_it.h Interrupt handlers header file
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- PWR/PWR_STANDBY/Inc/main.h header file for main.c
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- PWR/PWR_STANDBY/Src/system_stm32f4xx.c STM32F4xx system clock configuration file
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- PWR/PWR_STANDBY/Src/stm32f4xx_it.c Interrupt handlers
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- PWR/PWR_STANDBY/Src/main.c Main program
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- PWR/PWR_STANDBY/Src/stm32f4xx_hal_msp.c HAL MSP module
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@par Hardware and Software environment
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- This example runs on STM32F429xx/STM32F439xx devices.
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- This example has been tested with STMicroelectronics STM324x9I-EVAL RevB
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evaluation boards and can be easily tailored to any other supported device
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and development board.
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- STM324x9I-EVAL RevB Set-up
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- Use LED1 and LED2 connected respectively to PG.06 and PG.07 pins
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- Use the Key push-button connected to pin PC13 (EXTI_Line13)
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- Use the Wake-Up button connected to pin PA00
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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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