led.c

嵌入源代码式系统实验 跑马灯 键盘扫描 中断

//宏定义LED相关I/O口

#define IOPMOD (*(volatile unsigned *)0x56000010)//IO port mode register
#define IOPDATA (*(volatile unsigned *)0x56000014)//IO port data register

//================================
//名称：Led_Test
//功能：LED循环显示
//================================
void Led_Test()
{  
       unsigned long LED;
       
       IOPMOD &= (~(0x3<<20));//将IO 口置为输出模式
       IOPMOD |= ((0x1<<20));
       
       IOPMOD &= (~(0x3<<18));
       IOPMOD |= ((0x1<<18));
       
       IOPMOD &= (~(0x3<<16));
       IOPMOD |= ((0x1<<16));
       
       IOPMOD &= (~(0x3<<14));
       IOPMOD |= ((0x1<<14));
     
       
       IOPDATA = 0xf7f;	//置零时LED亮；
       
       Delay(100);
      
     
    for(;;)					//无限循环；
    {

        LED = IOPDATA; 
        LED = (LED<<1); 
        IOPDATA = LED;
        
        Delay(100);
        
        if(!(IOPDATA & 0x400))	//保证第四个LED点亮后重新点亮第一个LED;
       		IOPDATA=0xf7f;
       
       Delay(100);
    }

}
//============================
//名称：delay
//功能：延迟指定时间
//============================
void delay(unsigned int x)
{
    unsigned int i,j,k;
    
    for(i=0;i<=x;i++)
       for(j=0;j<0xff;j++)
          for(k=0;k<0xff;k++);
}