STM32微控制器的外部中断/事件控制器(External Interrupt/Event Controller,EXTI)管理了控制器的中断/事件线。每个中断/事件线都对应有一个边沿检测器,可以实现输入信号的上升沿检测和下降沿的检测。EXTI可以实现对每个中断/事件线进行单独配置,可以单独配置为中断或者事件,以及触发事件的属性。
实验程序:按键产生中断,控制LED灯开关状态的反转。
一、配置EXTI
void EXTI0_Config(void) { EXTI_InitTypeDef EXTI_InitStructure; GPIO_InitTypeDef GPIO_InitStructure; NVIC_InitTypeDef NVIC_InitStructure; // Enable GPIOC clock RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE); // Configure PC.00 pin as input floating GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_Init(GPIOC, &GPIO_InitStructure); // Enable AFIO clock RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); // Connect EXTI0 Line to PC.00 pin GPIO_EXTILineConfig(GPIO_PortSourceGPIOC, GPIO_PinSource0); // Configure EXTI0 line EXTI_InitStructure.EXTI_Line = EXTI_Line0; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); // Enable and set EXTI0 Interrupt to the lowest priority NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x0F; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x0F; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); }
二、配置LED
void LED_Config(void) { GPIO_InitTypeDef GPIO_InitStructure; // Enable GPIOB clock RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE); // Configure PB.0~15 pins as output push-pull GPIO_InitStructure.GPIO_Pin = GPIO_Pin_All; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz; GPIO_Init(GPIOB, &GPIO_InitStructure); }
三、中断处理程序
void EXTI0_IRQHandler(void) { if(EXTI_GetITStatus(EXTI_Line0) != RESET) { // Toggle LED GPIOB->ODR ^= GPIO_Pin_All; // Clear the EXTI line 0 pending bit EXTI_ClearITPendingBit(EXTI_Line0); } }
四、主程序
#include "stm32f10x.h" #include "bsp_led.h" #include "bsp_exti.h" int main(void) { // Configure LED LED_Config(); // Configure EXTI EXTI0_Config(); while(1) { __asm("nop"); } }