ARM:作业3

按键中断代码编写

代码:

key_it.h

#ifndef __KEY_IT_H__ #define __KEY_IT_H__ #include "stm32mp1xx_gpio.h" #include "stm32mp1xx_exti.h" #include "stm32mp1xx_rcc.h" #include "stm32mp1xx_gic.h" void key1_it_config(); void key2_it_config(); void key3_it_config(); #endif

key_it.c

#include"key_it.h" void key1_it_config() { //1.设置GPIOF时钟使能 RCC->MP_AHB4ENSETR |= (0X1<<5); // 2.将PF9管脚设置为输入 GPIOF->MODER &= (~(0x3<<18)); //3.设置由PF9产生EXTI9事件 EXTI->EXTICR3 &= (~(0XFF<<8)); EXTI->EXTICR3 |= (0x05<<8); // 4.设置EXTI9事件的检测方式为下降沿检测 EXTI->FTSR1 |= (0x1<<9); // 5.允许中断不屏蔽，可以被转发到GIC EXTI->C1IMR1 |= (0x1<<9); // 6.允许EXTI9（99号）中断被保存在组0中 GICD->ISENABLER[3]|= (0x1<<3); // 7.设置99号中断优先级 GICD->IPRIORITYR[24] &= (~(0x1f<<27)); GICD->IPRIORITYR[24] |= (0x0<<27); // 8.设置99号中断可以被CPU0处理 GICD->ITARGETSR[24] &= (~(0x3<<24)); GICD->ITARGETSR[24] |= (0x1<<24); //9.允许99号中断被转发到CPU接口层 GICD->CTRL |= 0x1; //10.设置中断优先级掩码 GICC->PMR |= (0x1f<<3); //11.允许中断被转发给CPU处理 GICC->CTRL |=0x1; } void key2_it_config() { //1.设置GPIOF时钟使能 RCC->MP_AHB4ENSETR |= (0X1 << 5); // 2.将PF7管脚设置为输入 GPIOF->MODER &= (~(0x3 << 14)); //3.设置由PF7产生EXTI7事件 EXTI->EXTICR2 &= (~(0XFF << 24)); EXTI->EXTICR2 |= (0x05 << 24); // 4.设置EXTI7事件的检测方式为下降沿检测 EXTI->FTSR1 |= (0x1 << 7); // 5.允许中断不屏蔽，可以被转发到GIC EXTI->C1IMR1 |= (0x1 << 7); // 6.允许EXTI7（97号）中断被保存在组0中 GICD->ISENABLER[3] |= (0x1 << 1); // 7.设置97号中断优先级 GICD->IPRIORITYR[24] &= (~(0x1f << 11)); GICD->IPRIORITYR[24] |= (0x0 << 11); // 8.设置97号中断可以被CPU0处理 GICD->ITARGETSR[24] &= (~(0x3 << 8)); GICD->ITARGETSR[24] |= (0x1 << 8); //9.允许97号中断被转发到CPU接口层 GICD->CTRL |= 0x1; //10.设置中断优先级掩码 GICC->PMR |= (0x1f << 3); //11.允许中断被转发给CPU处理 GICC->CTRL |= 0x1; } void key3_it_config() { //1.设置GPIOF时钟使能 RCC->MP_AHB4ENSETR |= (0X1 << 5); // 2.将PF8管脚设置为输入 GPIOF->MODER &= (~(0x3 << 16)); //3.设置由PF8产生EXTI8事件 EXTI->EXTICR3 &= (~(0XFF << 0)); EXTI->EXTICR3 |= (0x05 << 0); // 4.设置EXTI8事件的检测方式为下降沿检测 EXTI->FTSR1 |= (0x1 << 8); // 5.允许中断不屏蔽，可以被转发到GIC EXTI->C1IMR1 |= (0x1 << 8); // 6.允许EXTI8（98号）中断被保存在组0中 98/32=3...2 GICD->ISENABLER[3] |= (0x1 << 2); // 7.设置98号中断优先级 98/4=24...2 2*8+3=19 GICD->IPRIORITYR[24] &= (~(0x1f << 19)); GICD->IPRIORITYR[24] |= (0x0 << 19); // 8.设置98号中断可以被CPU0处理 98/4=24...2 GICD->ITARGETSR[24] &= (~(0x3 << 16)); GICD->ITARGETSR[24] |= (0x1 << 16); //9.允许97号中断被转发到CPU接口层 GICD->CTRL |= 0x1; //10.设置中断优先级掩码 GICC->PMR |= (0x1f << 3); //11.允许中断被转发给CPU处理 GICC->CTRL |= 0x1; }

do_irq.c

#include "key_it.h" extern void printf(const char *fmt, ...); unsigned int i = 0; void do_irq(void) { //获取中断号，根据中断号的不同进行不同的中断处理 int irqno; irqno=GICC->IAR&0x3ff; switch(irqno) { case 99: printf("key1 int\n"); //清除exti中断标志位 EXTI->FPR1 |=(0x1 << 3); //清除GICD中断标志位 GICD->ICPENDR[3] = (0x1 << 3); break; case 97: printf("key2 int\n"); // 清除exti中断标志位 EXTI->FPR1 |= (0x1 << 7); // 清除GICD中断标志位 GICD->ICPENDR[3] = (0x1 << 1); break; case 98: printf("key3 int\n"); // 清除exti中断标志位 EXTI->FPR1 |= (0x1 << 8); // 清除GICD中断标志位 GICD->ICPENDR[3] = (0x1 << 2); break; } //清除IAR寄存器的值 GICC->EOIR = irqno; }

main.c

#include "key_it.h" //封装延时函数 void delay(int ms) { int i,j; for(i=0;i<ms;i++) { for(j=0;j<2000;j++); } } int main() { //中断初始化 key1_it_config(); key2_it_config(); key3_it_config(); //现象是发送一个a串口工具打印一个b while(1) { printf("main func\n"); delay(2000); } return 0; }

运行结果: