为什么led_Init();会影响中断的？？？

lyf

[mw_shl_code=c,true]#include "sys.h" #include "delay.h" #include "usart.h" #include "led.h" #include "exti.h" int main(void) { GPIO_InitTypeDef GPIOE_STURCE; EXTI_InitTypeDef EXTI_GPIOE_PIN4; NVIC_InitTypeDef NVIC_Initstruce ; GPIOE_STURCE.GPIO_Mode = GPIO_Mode_IPU; GPIOE_STURCE.GPIO_Pin = GPIO_Pin_4 ; GPIOE_STURCE.GPIO_Speed = GPIO_Speed_2MHz ; EXTI_GPIOE_PIN4.EXTI_Line = EXTI_Line4 ; EXTI_GPIOE_PIN4.EXTI_LineCmd = ENABLE ; EXTI_GPIOE_PIN4.EXTI_Mode = EXTI_Mode_Interrupt ; EXTI_GPIOE_PIN4.EXTI_Trigger = EXTI_Trigger_Falling ; NVIC_Initstruce.NVIC_IRQChannel = EXTI4_IRQn ; NVIC_Initstruce.NVIC_IRQChannelCmd = ENABLE ; NVIC_Initstruce.NVIC_IRQChannelPreemptionPriority = 0x02; NVIC_Initstruce.NVIC_IRQChannelSubPriority = 0x02; LED_Init(); GPIO_Init(GPIOE , &GPIOE_STURCE ); RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOE,ENABLE);//????PORTA,PORTE?±?? RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE); //?????????????±?? GPIO_EXTILineConfig(GPIO_PortSourceGPIOE , GPIO_PinSource4 ); EXTI_Init(&EXTI_GPIOE_PIN4); NVIC_PriorityGroupConfig(NVIC_PriorityGroup_2); NVIC_Init(&NVIC_Initstruce); BEEP_Init(); delay_init(); while(1) { delay_ms(300); LED1 = ~LED1 ; } } void EXTI4_IRQHandler() { LED0 = 0; delay_ms(1000); delay_ms(1000); LED0= 1; EXTI_ClearITPendingBit(EXTI_Line4); } [/mw_shl_code]

请问为什么把LED_Init（）；放到while语句之前就不能实现外部中断了？？？初学stm32，请各位大神指教了····

八度空间

回复【楼主位】lyf:
---------------------------------
没开启IO时钟你就初始化端口啦？

lyf

回复【2楼】Badu_Space:
---------------------------------
刚学stm32，有很多地方都还不了解，不过编译运行能够正常运行，就没留意了。
刚才修改了一下程序，先开启IO时钟再初始化端口，问题决解了。谢谢一楼提醒···
顺便问一下，都是先开始时钟在初始化端口的吗？？？

lyf

回复【2楼】Badu_Space:
---------------------------------
再问一下，如果是先初始化端口再开启时钟有什么后果？？不甚感激啊！！！

八度空间

回复【4楼】lyf:
---------------------------------
最常见的就是不工作或者工作异常