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diff --git a/Projects/NUCLEO-WB35CE/Examples/PWR/PWR_STOP2_RTC/readme.txt b/Projects/NUCLEO-WB35CE/Examples/PWR/PWR_STOP2_RTC/readme.txt new file mode 100644 index 000000000..0a1a418e0 --- /dev/null +++ b/Projects/NUCLEO-WB35CE/Examples/PWR/PWR_STOP2_RTC/readme.txt @@ -0,0 +1,103 @@ +/** + @page PWR_Standby PWR_STOP2_RTC example + + @verbatim + ****************************************************************************** + * @file PWR/PWR_STOP2_RTC/readme.txt + * @author MCD Application Team + * @brief Description of the Power Stop 2 RTC example. + ****************************************************************************** + * + * Copyright (c) 2019 STMicroelectronics. All rights reserved. + * + * This software component is licensed by ST under BSD 3-Clause license, + * the "License"; You may not use this file except in compliance with the + * License. You may obtain a copy of the License at: + * opensource.org/licenses/BSD-3-Clause + * + ****************************************************************************** + @endverbatim + +@par Example Description + +How to enter the Stop 2 mode and wake-up from this mode using an external reset +or RTC wakeup timer. +It allows to measure the current consumption in Stop 2 mode with RTC enabled. + +In the associated software, the system clock is set to 64 MHz and the SysTick is +programmed to generate an interrupt each 1 ms. +The Low Speed Internal (LSI) clock is used as RTC clock source by default. +EXTI_Line19 is internally connected to the RTC Wakeup event. + +The system automatically enters Stop 2 mode 5 sec. after start-up. The RTC wake-up +is configured to generate an interrupt on rising edge about 33 sec. afterwards. +Current consumption in Stop 2 mode with RTC feature enabled can be measured during that time. +More than half a minute is chosen to ensure current convergence to its lowest operating point. + +After wake-up from Stop 2 mode, program execution is resumed. + +Two leds LED2 and LED1 are used to monitor the system state as following: + - LED1 ON: configuration failed (system will go to an infinite loop) + - LED2 toggling: system in Run mode + - LED2 off : system in Stop 2 mode + +These steps are repeated in an infinite loop. + +@note To measure MCU current consumption on board STM32WB Nucleo, + board configuration must be applied: + - remove all jumpers on connector JP5 to avoid leakages between ST-Link circuitry and STM32WB device. + - remove jumper JP2 and connect an amperemeter to measure current between the 2 connectors of JP2. + +@note This example can not be used in DEBUG mode due to the fact + that the Cortex-M4 core is no longer clocked during low power mode + so debugging features are disabled. + +@note Care must be taken when HAL_RCCEx_PeriphCLKConfig() is used to select + the RTC clock source; in this case the Backup domain will be reset in + order to modify the RTC Clock source, as consequence RTC registers (including + the backup registers) and RCC_CSR register are set to their reset values. + +@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 + +Power, PWR, Stop 2 mode, Interrupt, EXTI, Wakeup, Low Power, RTC, External reset + +@par Directory contents + + - PWR/PWR_STOP2_RTC/Inc/stm32wbxx_conf.h HAL Configuration file + - PWR/PWR_STOP2_RTC/Inc/stm32wbxx_it.h Header for stm32wbxx_it.c + - PWR/PWR_STOP2_RTC/Inc/main.h Header file for main.c + - PWR/PWR_STOP2_RTC/Src/system_stm32wbxx.c STM32WBxx system clock configuration file + - PWR/PWR_STOP2_RTC/Src/stm32wbxx_it.c Interrupt handlers + - PWR/PWR_STOP2_RTC/Src/main.c Main program + - PWR/PWR_STOP2_RTC/Src/stm32wbxx_hal_msp.c HAL MSP module + +@par Hardware and Software environment + + - This example runs on STM32WBxx devices + + - This example has been tested with STMicroelectronics NUCLEO-WB35CE + board and can be easily tailored to any other supported device + and development board. + + - NUCLEO-WB35CE Set-up + - Use LED2 and LED1 connected respectively to PB.00 and PB.05 pins + +@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 + + + * <h3><center>© COPYRIGHT STMicroelectronics</center></h3> + */ |