led.c

为2007年全国大学生电子设计大赛

//2007年8月20日晚 四位共阴数码管显示程序。
//
#define P_IOA_Data   (volatile unsigned int *)0x7000
#define P_IOA_Buffer  (volatile unsigned int *)0x7001
#define P_IOA_Dir   (volatile unsigned int *)0x7002
#define P_IOA_Attrib  (volatile unsigned int *)0x7003
#define P_IOB_Data   (volatile unsigned int *)0x7005
#define P_IOB_Buffer  (volatile unsigned int *)0x7006
#define P_IOB_Dir   (volatile unsigned int *)0x7007
#define P_IOB_Attrib  (volatile unsigned int *)0x7008
#define P_Watchdog_Clear  (volatile unsigned int *)0x7012
int LED[10]={0x3F00,0x0600,0x5B00,0x4F00,0x6600, 0x6D00,0x7D00,0x0700,0x7F00,0x6f00,0xFF00};


void DisplayLED(unsigned int num,unsigned int location)
{
	*P_IOA_Data&=0x00ff;
	*P_IOA_Data|=0x00f0;

	*P_IOA_Data = LED[num];
	*P_IOA_Data|=0x00f0;
	if( 1==location)
	{	
		*P_IOA_Data&=0xffef;
		
	}
	else if(2==location)
	{	
		*P_IOA_Data&=0xffdf;
		
	}
	else if(3==location)
	{	
		*P_IOA_Data&=0xffbf;
	
	}
	else if( 4==location )
	{	
		*P_IOA_Data&=0xff7f;
	}

	LDelay(20);

	*P_IOA_Data|=0x00f0;
}
void Init(){
*P_IOA_Dir|= 0xff00;           //设置A口高8位为同向高电平输出，控制LED和数码管的显示状态
*P_IOA_Attrib|= 0xff00;        
*P_IOA_Data&= 0x00ff;
*P_IOA_Dir|= 0x00f0;           //设置A5_A8口为同相低电平输出，LED和数码管的片选
*P_IOA_Attrib|= 0x00f0;
*P_IOA_Data |= 0x00f0;           //IO初始化
}
int LDelay()                                                   // 计数延时
{
    int DelayValue = 0;
    for (DelayValue = 0; DelayValue < 0x20; DelayValue++)
        *P_Watchdog_Clear = 1;                                   //清看门狗
}
void LedShow(unsigned int j)//显示任意一个十进制数
{
	Init();
			
	//DisplayLED(j/1000,1);
	//DisplayLED(	j/100%10,2);
//	DisplayLED(	j%100/10,3);
	//DisplayLED(	j%1000%100%10,4);
						
	DisplayLED( (j%10000)/1000,1);

	DisplayLED(	(j%1000)/100,2);

	DisplayLED(	(j%100)/10,3);

	DisplayLED(	(j%10)/1,4);

}