ARM Cortex M3共有256个中止。
STM32F103CB共有43个外部中止和16个内部中止。
具有相同数值编号的IO口被分配为同一组，共用一条中止请求线，如下图：
所以共有15条中止线，别的
●EXTI线16连接到PVD输出
●EXTI线17连接到RTC闹钟事情
●EXTI线18连接到USB唤醒事情
寄存器：1、外部中止装备寄存器AFIO_EXTxCR1->用于挑选输入中止源Pin 0..3
AFIO_EXTxCR2->用于挑选输入中止源Pin 0..7
AFIO_EXTxCR2->用于挑选输入中止源Pin 8..11
AFIO_EXTxCR2->用于挑选输入中止源Pin 12..15
(阐明：5个端口PORTA..E，每个端口各有16位可供挑选)
2、中止屏蔽寄存器EXTI_IMR–>屏蔽线上的中止请求共19路
3、事情屏蔽寄存器EXTI_EMR–>屏蔽线上的事情共19路
4、上升沿触发挑选寄存器EXTI_RTSR->设置相应线为上升沿触发19位
5、下降沿触发挑选寄存器EXTI_FTSR->设置相应线为上升沿触发19位
6、挂起寄存器EXTI_PR>中止线上发生了挑选的边缘事情时置119位
7、软件中止事情寄存器EXTI_SWIER>写该位能够将EXTI_PR中相应的位值高，假如EXTI_IMR或EXTI_EMR使能，则能够发生相应的中止
装备流程：中止在运用前有必要对中止线进行装备并激活
1、装备相应的IO口为输入，浮空输入时一定要加上拉或者是下拉
2、舱位IO口复用时钟，设置IO与中止线的映射联系->AFIO_EXTxCR1
3、设置相应中止触发条件->EXTI_IMR、EXTI_RTSR、EXTI_FTSR
4、在NVIC中舱位并使能中止，对中止分组进行装备
5、编写中止服务函数
>
编写中止程序的过程：（库函数版）
1.初始化体系时钟和端口时钟，在此需注意设置完端口时钟外还须将端口设置为功用复用IO时钟。RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE)
2.初始化GPIO。
3.中止装备，包含两部分（两个函数），中止装备和中止优先级装备。
中止装备：结构体：EXTI_InitTypeDef 。清空中止线、中止线映射CPU、中止线挑选、中止形式、触发方法、使能。
优先级装备：结构体：NVIC_InitTypeDef。选组、挑选IRQ通道、设置抢占优先级、设置从优先级、使能。
EG: EXTI_Configuration() 和 NV%&&&&&%_Configuration()
分组状况：
| 优先级组别 | 抢占式优先级 | 副优先级 |
| 4 | 4位/16级 | 0位/0级 |
| 3 | 3位/8级 | 1位/2级 |
| 2 | 2位/4级 | 2位/4级 |
| 1 | 1位/2级 | 3位/8级 |
| 0 | 0位/0级 | 4位/6级 |
4.中止服务程序。比方0号中止线对应函数 void EXTI0_IRQHandler(void)
示例：按键改动LED的状况
1.主要功用是按键呼应中止然后改动LED的状况。
2.按键所属端口：GPIOB，LED所属端口：GPIOB
3.按键管脚：PB0~PB7
4.LED管脚：PB8~PB15
5.PB0~PB5别离顺次操控PB8~PB13
1 #include "pbdata.h"2 #include "led.h"3 #include "key.h"4 #include "misc.h"5 #include "stm32f10x_exti.h"6 7 void RCC_Configration(void)8 {9 SystemInit();10 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);11 RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); //功用复用IO时钟12 }13 14 void GPIO_Configration(void)15 {16 GPIO_LED_Configration();17 GPIO_KEY_Configration();18 }19 20 /*21 *中止装备*22 */23 void EXTI_Configuration(void)24 {25 EXTI_InitTypeDef EXTI_InitStructure;26 27 EXTI_ClearITPendingBit(EXTI_Line0); //清空中止线28 EXTI_ClearITPendingBit(EXTI_Line1);29 EXTI_ClearITPendingBit(EXTI_Line2);30 EXTI_ClearITPendingBit(EXTI_Line3);31 EXTI_ClearITPendingBit(EXTI_Line4);32 EXTI_ClearITPendingBit(EXTI_Line5);33 EXTI_ClearITPendingBit(EXTI_Line6);34 EXTI_ClearITPendingBit(EXTI_Line7);35 36 GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource0);//映射37 GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource1);38 GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource2);39 GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource3);40 GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource4);41 GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource5);42 GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource6);43 GPIO_EXTILineConfig(GPIO_PortSourceGPIOB, GPIO_PinSource7);44 45 EXTI_InitStructure.EXTI_Line=EXTI_Line0 EXTI_Line1 EXTI_Line2 EXTI_Line3 EXTI_Line4 EXTI_Line5 EXTI_Line6 EXTI_Line7; //挑选中止线46 47 EXTI_InitStructure.EXTI_Mode=EXTI_Mode_Interrupt; //设置形式48 EXTI_InitStructure.EXTI_Trigger=EXTI_Trigger_Falling; //设置触发方法49 EXTI_InitStructure.EXTI_LineCmd=ENABLE; //使能50 51 EXTI_Init(&EXTI_InitStructure);52 }53 54 void NVIC_Configuration0(void) //优先级设置函数55 {56 NVIC_InitTypeDef NVIC_InitStructure; 57 58 NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3); 59 60 NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn; //挑选IRQ通道61 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0; //抢占优先级设置62 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; //次优先级设置63 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 64 NVIC_Init(&NVIC_InitStructure); 65 }66 67 void NVIC_Configuration1(void) 68 {69 NVIC_InitTypeDef NVIC_InitStructure; 70 71 // NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3); 72 73 NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn; 74 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 1; 75 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; 76 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 77 NVIC_Init(&NVIC_InitStructure); 78 }79 80 void NVIC_Configuration2(void)81 {82 NVIC_InitTypeDef NVIC_InitStructure; 83 84 // NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3); 85 86 NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn; 87 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2; 88 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; 89 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 90 NVIC_Init(&NVIC_InitStructure); 91 }92 93 void NVIC_Configuration3(void)94 {95 NVIC_InitTypeDef NVIC_InitStructure; 96 97 // NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3); 98 99 NVIC_InitStructure.NVIC_IRQChannel = EXTI3_IRQn; 100 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3; 101 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; 102 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 103 NVIC_Init(&NVIC_InitStructure); 104 }105 106 void NVIC_Configuration4(void)107 {108 NVIC_InitTypeDef NVIC_InitStructure; 109 110 // NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3); 112 NVIC_InitStructure.NVIC_IRQChannel = EXTI4_IRQn; 113 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 4; 114 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; 115 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 116 NVIC_Init(&NVIC_InitStructure); 117 }118 119 void NVIC_Configuration5(void)120 {121 NVIC_InitTypeDef NVIC_InitStructure; 122 123 // NVIC_PriorityGroupConfig(NVIC_PriorityGroup_3); 124 125 NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn; 126 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 5; 127 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1; 128 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; 129 NVIC_Init(&NVIC_InitStructure); 130 }131 132 int main(void)133 {134 RCC_Configration();135 GPIO_Configration();136 EXTI_Configuration();137 NVIC_Configuration0();138 NVIC_Configuration1();139 NVIC_Configuration2();140 NVIC_Configuration3();141 NVIC_Configuration4();142 NVIC_Configuration5();143 while(1);144 }
