1. Article purpose
The purpose of this article is to give an overview of the software APIs available on the Arm® Cortex®-M4 (also named MCU) side to handle the low power modes.
2. Low power modes available on the chip
The low power modes are handled by RCC and PWR peripherals.
See Power overview for mode description or refer to STM32MP15 reference manuals for the full description of the modes.
2.1. Wakeup sources
The low power modes are left due to a wakeup event. It can be configured by setting the wakeup control feature of the IP and activating the corresponding EXTI on MCU side.
The wake sources are listed in the Power overview page.
3. Software overview
The power HAL is used to select the Cortex-M4 low power mode.
Further information on HAL can be found here: STM32CubeMP1 architecture
3.1. APIs description
The power HAL supports the following APIs related to power management:
HAL_PWR_EnterSLEEPMode: CSleep mode is enteredHAL_PWR_EnterStopMode: CStop mode is entered allowing Stop as the deepest platform low power modeHAL_PWR_EnterStandbyMode: CStop mode is entered allowing Standby as the deepest platform low power mode
4. Code source location
STM32CubeMP1 Package provides power HAL driver:
- Drivers/STM32MP1xx_HAL_Driver/Src/stm32mp1xx_hal_pwr.c
- Drivers/STM32MP1xx_HAL_Driver/Inc/stm32mp1xx_hal_pwr.h