智能车制作

标题: STM32F4演示例程之操作EXTI的练习 [打印本页]

作者: demon 时间: 2012-5-20 23:56
标题: STM32F4演示例程之操作EXTI的练习
[attach]24768[/attach]
/************************************
标题：操作EXTI的练习
软件平台：IAR for ARM6.21
硬件平台：stm32f4-discovery
主频：168M

author：小船
data：2012-01-17
*************************************/
#include <stm32f4xx.h>
void Led_Init (void);
void main ()
{

  RCC->AHB1ENR |= 0x00000009; //使能GPIOD和GPIOA时钟
  RCC->APB2ENR |= (1<<14);  //使能syscfg时钟
  SCB->AIRCR = 0x05AF0000 | 0x400;  //中断优先级分组抢占：响应=3:1

  Led_Init();

  GPIOA->MODER &= 0xFFFFFFFC; //浮空输入模式
  GPIOA->PUPDR &= 0xFFFFFFFC;

  EXTI->IMR |= ( 1 << 0 );  //不屏蔽外中断线0

  EXTI->FTSR |= ( 1 << 0 ); //下降沿触发

  SYSCFG->EXTICR[1] &= 0xFFFFFF00;  //配置外中断线0到PA口

  NVIC->IP[6] = 0xe0; //最低抢占优先级，最高响应优先级1110

  NVIC->ISER[0] |= (1<<6);  //使能中断线6，也就是外中断0


  while(1)
  {
  };
}
void Led_Init()
{
  GPIOD->MODER &= 0x00FFFFFF; //设置PD12,13,14,15输出
  GPIOD->MODER |= 0x55000000;

  GPIOD->OTYPER &= 0xFFFF0FFF; //设置PD12,13,14,15推挽输出

  GPIOD->OSPEEDR &= 0x00FFFFFF; //PD12,13,14,15 速度100m
  GPIOD->OSPEEDR |= 0xff000000;

  GPIOD->PUPDR &= 0x00FFFFFF;  //PD12,13,14,15 无上拉无下拉

  GPIOD->BSRRH = 0xf000;  //reset register GPIOx_BSRRH, write only
                        //set register GPIOx_BSRRL, write only
  SYSCFG->CMPCR = 0x00000001; //使用IO补偿单元
}
void EXTI0_IRQHandler(void)
{
  uint32_t tmp;
  if(EXTI->PR & 0x00000001 != 0)  //检查是不是外中断0挂起
  {
tmp = (~GPIOD->ODR) & 0x0000f000; //PD15 14 13 12翻转,板子上四个LED的亮灭
GPIOD->ODR &= 0xffff0fff;
GPIOD->ODR |= tmp;

EXTI->PR = (1<<0);  //外中断0解除挂起
  }
}

作者: 0726silence 时间: 2012-5-21 12:49
顶，正打算学32 的

欢迎光临智能车制作 (http://dns.znczz.com/)