单片机实验2提示

单片机实验2提示

参考程序，未必准确：

#include "8052.h"
#define LSA   P1_5  			
#define LSB   P1_6  			
#define LSC   P1_7
unsigned int cnt=0;
unsigned char T0RH = 0; 	//T0 重载值的高字节
unsigned char T0RL = 0; 	//T0 重载值的低字节
signed char sec;
signed char sec_all=88;
signed char count=0;
unsigned char smgduan[]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0x0f8,0x80,0x90};
//共阳极的显示代码表0~9 
void EXINT0() __interrupt 0;
void Timer0() __interrupt 1;


void ConfigTimer0(unsigned int ms)
{
	unsigned long tmp; 	 //临时变量
	tmp = 11059200 / 12; 	 //定时器计数频率
	tmp = (tmp * ms) / 1000;  //计算所需的计数值
	tmp = 65536 - tmp; 	 //计算定时器重载值
	tmp = tmp + 18; 	 //补偿中断响应延时造成的误差
	T0RH = (unsigned char)(tmp>>8); 	//定时器重载值拆分为高低字节
	T0RL = (unsigned char)tmp;
	TMOD &= 0xF0; 		//清零 T0 的控制位
	TMOD |= 0x01; 		//配置 T0 为模式 1
	TH0 = T0RH; 		//加载 T0 重载值
	TL0 = T0RL;
	ET0 = 1; 		//使能 T0 中断
}
void EXINT0() __interrupt 0     	
{
	count++;				
}
void Timer0() __interrupt 1
{
	TH0 = T0RH; 	//重新加载重载值
	TL0 = T0RL;
	cnt++; 		//中断次数加1
	if (cnt >= 100) //中断100次=1s
	{
		cnt = 0;
		sec--; 
		if (sec < 0)   //当显示值到0后，闪烁
		{
			sec = 0;
		}
	}
}
void LedScan(unsigned char pos,unsigned char dispcode)
{
    unsigned char i;
    for(i=0;i<=pos;i++)
    {		
	switch(pos)	                  //位选，选择点亮的数码管，
	{
		case(0):
		LSA=1;LSB=0;LSC=0; break; //显示
		case(1):
		LSA=0;LSB=1;LSC=0; break; //显示第1位
		case(2):
		LSA=1;LSB=1;LSC=0; break; //显示第2位
		case(3):
		LSA=0;LSB=0;LSC=1; break; //显示第3位
	}
	P0=dispcode;	                  //发送段码			
    }	
}
void sys_init(void)
{
    	LSA = 0;
    	LSB = 0;
    	LSC = 0;
	cnt = 0;                 		//中断次数计数器
	sec = sec_all;                		//秒数初值
	ConfigTimer0(10); 			//配置 T0 定时 10ms
	EA=1;                                    //开中断
	IT0=0; 
	EX0=1;
//	IT1=1; 
//	EX1=1;
//	PX1=1;	  				
        TR0=1; 
}

void main(void)
{
    sys_init();
    while(1)
    {
	if(count%2==0)
	{
		TR0 = 1;
	}
	else
	{
		TR0 = 0;
	}
	if((cnt>49)&&(sec==0))
	{
		LedScan(0,0xff);    		//显示个位值	
		LedScan(1,0xff);    		//显示个位值
	}
	else
	{
		LedScan(0,smgduan[sec%10]);    	//显示个位值
		LedScan(1,smgduan[sec/10]);    	//显示十位值	
	}
      
    }
}