NVIC in WFI mode example

  ******************** (C) COPYRIGHT 2014 STMicroelectronics *******************
  * @file    NVIC/NVIC_WFI_Mode/readme.txt 
  * @author  MCD Application Team
  * @version V1.4.0
  * @date    24-July-2014
  * @brief   Description of the NVIC in WFI mode example.
  ******************************************************************************
  *
  * Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
  * You may not use this file except in compliance with the License.
  * You may obtain a copy of the License at:
  *
  *        http://www.st.com/software_license_agreement_liberty_v2
  *
  * Unless required by applicable law or agreed to in writing, software 
  * distributed under the License is distributed on an "AS IS" BASIS, 
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  *
  ******************************************************************************
   

Example Description

This example shows how to enter the system to WFI mode and wake-up from this mode using External interrupt.

In the associated software, the system clock is set to 48 MHz. When the user presses on the Key push button, the MCU enters in WFI mode. If the user presses again on the Key push button, LED3 is toggled with a frequency depending on the system clock, this is used to indicate whether the MCU is in WFI or RUN mode.

Pressing Tamper push button (generates rising edge on EXTI Line13) will put the core in the WFI mode, causing the LED3 to stop toggling. To wake-up from WFI mode you have to press again on the button which generates an interrupt which exits the system from WFI mode. Then LED3 restarts toggling.

Directory contents

• NVIC/NVIC_WFI_Mode/stm32f0xx_conf.h Library Configuration file
• NVIC/NVIC_WFI_Mode/stm32f0xx_it.c Interrupt handlers
• NVIC/NVIC_WFI_Mode/stm32f0xx_it.h Interrupt handlers header file
• NVIC/NVIC_WFI_Mode/main.c Main program
• NVIC/NVIC_WFI_Mode/main.h Header for main.c module
• NVIC/NVIC_WFI_Mode/system_stm32f0xx.c STM32F0xx system source file

Note:

The "system_stm32f0xx.c" is generated by an automatic clock configuration tool and can be easily customized to meet user application requirements. To select different clock setup, use the "STM32F0xx_Clock_Configuration_VX.Y.Z.xls" provided with the AN4055 package available on ST Microcontrollers

Hardware and Software environment

• This example runs on STM32F0xx devices.

• This example has been tested with STMicroelectronics STM320518-EVAL and STM32072B-EVAL including respectively STM32F051R8T6 and STM32F072VBT6 devices and can be easily tailored to any other supported device and development board

• STM320518-EVAL Set-up
  • Use the Tamper push-button
• STM32072B-EVAL Set-up
  • Use the Tamper push-button

How to use it ?

In order to make the program work, you must do the following :

• Copy all source files from this example folder to the template folder under Project
• Open your preferred toolchain
• Select STM32F051 workspace
• If the used device is STM32F051R8T6 choose STM32F051 project
  • Add the following files to the project source list
    • Utilities\STM32_EVAL\STM320518_EVAL\stm320518_eval.c
• If the used device is STM32F072VBT6 choose STM32F072 project
  • Add the following files to the project source list
    • Utilities\STM32_EVAL\STM32072B_EVAL\stm32072b_eval.c
• Rebuild all files and load your image into target memory
• Run the example

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