title: How to enable interrupt function in sw4stm32
body: <p>I use  SW4STM32 toolchain,I want to bliking led using timer2 when overflow, in STM32103RET,
  here is my functions to turn led on and of.</p>
  
  <pre><code>void TurnOnLed(){
      HAL_GPIO_WritePin(GPIOA,GPIO_PIN_10,GPIO_PIN_SET);
  }
  
  void TurnOffLed()
  {
      HAL_GPIO_WritePin(GPIOA,GPIO_PIN_10,GPIO_PIN_RESET);
  }
  </code></pre>
  
  <p>the timer2 initilizing has been set by stm32 cube mx, but i do not know which function called when timer2 overflows?</p>