STM32外部中断配置例程
STM32 外部中断配
NVIC_Configuration 函数实现配置嵌套向量中断中断优先级并使能中断。其中的NVIC_PriorityGroupConfig 函数配置中断优先级的组织方式,STM32 的嵌套向量中断控制器可以配置16 个可编程的优先等级,使用了4 位表示中断优先级(2 的4 此方就是16),16 个可编程的优先等级又可以分为主优先级和次优先级,例如参数NVIC_PriorityGroup_1表示1bit 主优先级(pre-emption priority)3 bits 次优先级(subpriority )。
一、配置中断
1、分配中断向量表:
/* Set the Vector Table base location at 0x20000000 */
NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
2、设置中断优先级:
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0); //设置中断优先级
3、初始化外部中断:
/*允许EXTI4中断*/
NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQChannel; //中断通道NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority= PreemptionPriorityValue; //占先优先级
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; //响应(次级)优先级NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //通道中断使能
NVIC_Init(&NVIC_InitStructure); //初始化中断
注意:如果我们配置的外部针脚为PA4,或PB4,或PC4,PD4等,那么采用的外部
中断也必须是EXTI4,同样,如果外部中断针脚是PA1,PB1,PC1,PD1 那么中断就要用EXTI1,其他类推。
二、配置GPIO针脚作为外部中断的触发事件
1、选择IO针脚
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
注意,如果的针脚是端口的4号针脚,配置的中断一定是EXTI4
2、配置针脚为输入
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
3、初始化针脚
GPIO_Init(GPIOD,&GPIO_InitStructure);
3配置EXTI线,使中断线和IO针脚线连接上
1、将EXTI线连接到IO端口上
将EXTI线4连接到端口GPIOD的第4个针脚上
GPIO_EXTILineConfig(GPIO_PortSourceGPIOD,GPIO_PinSource4);
注意:如果配置的针脚是4号,那么参数必须是GPIO_PinSource4
如果配置的针脚是3号,那么参数必须是GPIO_PinSource3
2、配置中断边沿
/*配置EXTI线4上出现下降沿,则产生中断*/
EXTI_InitStructure.EXTI_Line = EXTI_Line4;
注意:如果配置的4号针脚,那么EXTI_Line4是必须的
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; //下降沿触发
EXTI_InitStructure.EXTI_LineCmd = ENABLE; //中断线使能
EXTI_Init(&EXTI_InitStructure); //初始化中断
EXTI_GenerateSWInterrupt(EXTI_Line4); //EXTI_Line4中断允许
到此中断配置完成,可以写中断处理函数。
举例:
配置函数
/************************************************************* ************
* 函数名NVIC_Configration
* 描述配置各个中断寄存器
************************************************************** **************/
void NVIC_Configration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
//#ifdef VECT_TAB_RAM
/* Set the Vector Table base location at 0x20000000 */
NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0);
//#else /* VECT_TAB_FLASH */
/* Set the Vector Table base location at 0x08000000 */
//NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0);
//#endif
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0); //设置中断优先级
/*允许EXTI4中断*/
NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQChannel;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = PreemptionPriorityValue;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/*允许EXTI9中断*/
NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQChannel;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/*配置SysTick处理优先级:优先级以及子优先级*/
}
/************************************************************* ***********
* 函数名GPIO_Configuration(void)
* 描述配置TIM2针脚
************************************************************** **********/
void GPIO_Configuration(void){
/* GPIO_InitTypeDef GPIO_InitStructure;
GPIO_InitStructure.GPIO_Pin=
GPIO_Pin_0|GPIO_Pin_1|GPIO_Pin_2|GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA,&GPIO_InitStructure);
*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_All;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_2MHz;
GPIO_Init(GPIOC,&GPIO_InitStructure);
/*配置GPIOD的第一个管角为浮动输入*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOD,&GPIO_InitStructure);
/*配置GPIOB的第9个管脚为浮动输入*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_9;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
GPIO_Init(GPIOB,&GPIO_InitStructure);
}
/************************************************************* *
* 函数SysTick_Configuration
* 描述设置SysTick
************************************************************** */
void SysTick_Configuration(void)
{
/*配置HCLK 时钟做为SysTick 时钟源*/
SysTick_CLKSourceConfig(SysTick_CLKSource_HCLK_Div8); //系统时钟8分频72MHz
NVIC_SystemHandlerPriorityConfig(SystemHandler_SysTick, 8,2);
/*SysTick Interrupt each 1000Hz with HCLK equal to 72MHz*/
SysTick_SetReload(9000);//中断周期1ms
/*Enable the SysTick Interrupt */
SysTick_ITConfig(ENABLE);//打开中断
SysTick_CounterCmd(SysTick_Counter_Enable);
SysTick_CounterCmd(SysTick_Counter_Clear);
}
/************************************************************* *****************
* 函数名EXTI_Configuration
* 描述配置EXTI线
************************************************************** ****************/
void EXTI_Configuration(void){
/*将EXTI线4连接到PD4*/
GPIO_EXTILineConfig(GPIO_PortSourceGPIOD,GPIO_PinSource4);
/*配置EXTI线4上出现下降沿,则产生中断*/
EXTI_InitStructure.EXTI_Line = EXTI_Line4;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
EXTI_GenerateSWInterrupt(EXTI_Line4);
/*将EXTI线9连接到PB9上*/
GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource9);
/*将EXTI线9上出现下降沿产生中断*/
EXTI_InitStructure.EXTI_Line = EXTI_Line9;
EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
EXTI_InitStructure.EXTI_LineCmd = ENABLE;
EXTI_Init(&EXTI_InitStructure);
EXTI_GenerateSWInterrupt(EXTI_Line9);
}
中断函数:
void EXTI4_IRQHandler(void)
{
if(EXTI_GetITStatus(EXTI_Line4)!= RESET)
{
if(Ledflag == 0)
{
Ledflag = 1;
GPIOC->ODR |= 0X00000080;
}
else
{
Ledflag = 0;
GPIOC->ODR &= 0XFFFFFF7F;
}
}
EXTI_ClearITPendingBit(EXTI_Line4); //清除EXTI0线路挂起位
}
注:时钟设置的时候最好加上这句:
RCCRCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); // 使能AFIO时钟
================================================ /************************************************************* ************************************************************** 例程名称:外部中断实验
实验硬件:DP-miniSTM32
硬件连接:指示灯连接PA1
按钮连接PA3
功能描述:本例程实现外部中断的输入试验,按下按钮,指示灯闪烁一下
************************************************************** ******/
#include
#include "STM32_Init.h" // STM32 Initialization
/************************************************************* *********
* 名称:Delay()
*************************************************************/ void Delay(vu16 cnt) {
uint16 i,j;
for (i=0;i { for (j=0;j<1000;j++) { } } } /************************************************************* ********* * 名称:RCC_Configuration() *************************************************************/ void RCC_Configuration(void) { ErrorStatus HSEStartUpStatus; //使能外部晶振 RCC_HSEConfig(RCC_HSE_ON); //等待外部晶振稳定 HSEStartUpStatus = RCC_WaitForHSEStartUp(); //如果外部晶振启动成功,则进行下一步操作 if(HSEStartUpStatus==SUCCESS) { //设置HCLK(AHB时钟)=SYSCLK RCC_HCLKConfig(RCC_SYSCLK_Div1); //PCLK1(APB1) = HCLK/2 RCC_PCLK1Config(RCC_HCLK_Div2); //PCLK2(APB2) = HCLK RCC_PCLK2Config(RCC_HCLK_Div1); RCC_PLLConfig(RCC_PLLSource_HSE_Div1, RCC_PLLMul_4); //启动PLL RCC_PLLCmd(ENABLE); //等待PLL稳定 while(RCC_GetFlagStatus(RCC_FLAG_PLLRDY) == RESET); //系统时钟SYSCLK来自PLL输出 RCC_SYSCLKConfig(RCC_SYSCLKSource_PLLCLK); //切换时钟后等待系统时钟稳定 while(RCC_GetSYSCLKSource()!=0x08); } /* RCC system reset(for debug purpose) */ RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_AFI O , ENABLE); //给GPIOA和重映射提供时钟,注意:一定要设置RCC_APB2Periph_AFIO } /************************************************************* ********* * 名称:GPIO_Configuration() *************************************************************/ void GPIO_Configuration(void) { GPIO_InitTypeDef GPIO_InitStructure; /*设置PA3为输入*/ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_Init(GPIOA,&GPIO_InitStructure); /*设置PA1为输出*/ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_1; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_10MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP; GPIO_Init(GPIOA, &GPIO_InitStructure); } /************************************************************* ********* * 名称:EXTI_Configuration() ************************************************************** *********/ void EXTI_Configuration(void) { EXTI_InitTypeDef EXTI_InitStructure; /* Configure EXTI Line3 to generate an interrupt on falling edge */ EXTI_InitStructure.EXTI_Line = EXTI_Line3; //外部中断通道3 EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; //下降沿触发EXTI_InitStructure.EXTI_LineCmd = ENABLE; //使能 EXTI_Init(&EXTI_InitStructure); GPIO_EXTILineConfig(GPIO_PortSourceGPIOA, GPIO_PinSource3); //将PA3连接到外部中断通道3 } /************************************************************* ********* * 名称:NVIC_Configuration() *************************************************************/ void NVIC_Configuration(void) { NVIC_InitTypeDef NVIC_InitStructure; #ifdef VECT_TAB_RAM /* Set the Vector Table base location at 0x20000000 */ NVIC_SetVectorTable(NVIC_VectTab_RAM, 0x0); #else/* VECT_TAB_FLASH */ /* Set the Vector Table base location at 0x08000000 */ NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); #endif NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0); //抢占式优先级别设置为无抢占优先级 NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQChannel; //指定中断源NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //指定响应优先级别1 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; //使能外部中断通道3 NVIC_Init(&NVIC_InitStructure); } int main (void) { RCC_Configuration(); //配置时钟 GPIO_Configuration(); //配置IO口 NVIC_Configuration(); //中断配置 EXTI_Configuration(); //外部中断配置 while(1) { } } /************************************************************ ********** * 说明:将LED灯的连接到PA1 *************************************************************/ void EXTI3_IRQHandler (void) { if(EXTI_GetITStatus(EXTI_Line3) != RESET) { //添加中断处理程序 GPIO_WriteBit(GPIOA, GPIO_Pin_1,(BitAction)0); Delay(1000); GPIO_WriteBit(GPIOA, GPIO_Pin_1,(BitAction)1); Delay(1000); EXTI_ClearFlag(EXTI_Line3); //清除中断标志(必须) EXTI_ClearITPendingBit(EXTI_Line3); // 以上两条语句作用相同 } } ================================================ 在使用EXTI的时候,因为没有开启时钟没有开启RCC_APB2Periph_AFIO时钟,让我调试吃了不少苦头,看来还要好好看看stm32的时钟啊 现在给出我的exti8的配置 首先一定要记得配置 RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); // 使能AFIO时钟 //GPIOB8作为中断脚,配置为浮空输入 void GPIO_Configuration(void) { GPIO_InitTypeDef GPIO_InitStructure; /* Configure PB8 as input floating */ GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING; GPIO_Init(GPIOB,&GPIO_InitStructure); } 继续配置NVIC void NVIC_Configuration(void) { NVIC_InitTypeDef NVIC_InitStructure; NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn; NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); /* Configure the NVIC Preemption Priority Bits*/ NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0); /* Set the Vector Table base location at 0x08000000 */ NVIC_SetVectorTable(NVIC_VectTab_FLASH, 0x0); } 然后配置EXTI ,把PB8连接到EXTI void EXTI_Configuration(void) { EXTI_InitTypeDef EXTI_InitStructure; /*connect PB8 to EXTI*/ GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource8); /*Config EXTI8*/ EXTI_InitStructure.EXTI_Line = EXTI_Line8; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt; EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling; EXTI_InitStructure.EXTI_LineCmd = ENABLE; EXTI_Init(&EXTI_InitStructure); //EXTI_GenerateSWInterrupt(EXTI_Line8); } 这样就可以中断了, 在中断函数里面记得清除标志位 void EXTI9_5_IRQHandler(void) { if(EXTI_GetITStatus(EXTI_Line8)!= RESET) { EXTI_ClearITPendingBit(EXTI_Line8); } }