Stm32f030 external interrupt configuration

1、 explain

STM32F030 chip ,PC13 Trigger for external interrupt , Configuration of falling edge ;

Attention opening SYSCFG The clock ;

void back_key_init(void)
{
	EXTI_InitTypeDef EXTI_InitStructure;		//EXTIx Breakline configuration 
	NVIC_InitTypeDef NVIC_InitStructure;		//EXTIx Interrupt vector configuration 

	pin_input_init(BACK_KEY);					// Floating input , Schematic has been pulled up 
	
	// Configure the key pin as falling edge interrupt 	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_SYSCFG,ENABLE);	
	SYSCFG_EXTILineConfig(EXTI_PortSourceGPIOC,EXTI_PinSource13);	// take EXTI13 Point to PC13
		
	EXTI_InitStructure.EXTI_Line=EXTI_Line13;
	EXTI_InitStructure.EXTI_Mode=EXTI_Mode_Interrupt;
	EXTI_InitStructure.EXTI_Trigger=EXTI_Trigger_Falling;
	EXTI_InitStructure.EXTI_LineCmd=ENABLE;
	EXTI_Init(&EXTI_InitStructure);
	
	NVIC_InitStructure.NVIC_IRQChannel=EXTI4_15_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPriority=0x01;
	NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
	NVIC_Init(&NVIC_InitStructure);

}

void EXTI4_15_IRQHandler(void){
	
	if(EXTI_GetITStatus(EXTI_Line13)!=RESET){	// Judgment is EXTI_Line13
		
	}
	EXTI_ClearFlag(EXTI_Line13);				// Clear the flag bit when exiting the interrupt 
}