#include<AT89X51.h>

char display[]={0X3F,0X06,0X5B,0X4F,0X66,0X6D,0X7D,0X07,0X7F,0X6F,0XF7,0X7C,0X39,0X5E,0X79,0X71};
//char cache[6]={2,2,5,9,5,8};			//时钟的 十	分	秒
char hour=20,minute=20,second=20;
char year=21,month=12,day=20;

void DelayXms(unsigned int xms)			//延时函数
{
    unsigned int i,j;
    
    for(i=xms; i>0; i--)
    {
        for(j=240; j>0; j--)
        { }
    }
}


void DisplayCode(char value)
{
    P0=display[value];
}

void screen1(void)
{
    int x;
    P2=0xfe;
    DisplayCode(hour/10);
    DelayXms(1);
    P2=0xfd;
    x=display[hour%10];
    x|=0x80;
    P0=x;   
    DelayXms(1);

    P2=0xfb;
    DisplayCode(minute/10);
    DelayXms(1);
    P2=0xf7;
    x=display[minute%10];
    x|=0x80;
    P0=x;
    DelayXms(1);

    P2=0xef;
    DisplayCode(second/10);
    DelayXms(1);
    P2=0xdf;
    x=display[second%10];
	P0=x;
    DelayXms(1);

}
void screen2()
{
	int x;
    P2=0xfe;
    DisplayCode(year/10);
    DelayXms(1);
    P2=0xfd;
    x=display[year%10];
    x|=0x80;
    P0=x;
    DelayXms(1);
    P2=0xfb;
    DisplayCode(month/10);
    DelayXms(1);
    P2=0xf7;
    x=display[month%10];
    x|=0x80;
    P0=x;
    DelayXms(1);
    P2=0xef;
    DisplayCode(day/10);
    DelayXms(1);
    P2=0xdf;
    x=display[day%10];
    P0=x;
    DelayXms(1);
}
unsigned char KeyScan(void)
{
	char KeyValue;
	
	P1 = 0x0f;			//P1 == 00001111
	if(P1!=0x0f)		//P1 != 00001111
	{
		switch(P1)
		{
			case 0x0e:	//00001110	P1.0=0
						P1 = 0xf0;
						switch(P1)
						{
							case 0x70:	//01110000	P1.7=0
										KeyValue = 12;break;
							case 0xb0:	//10110000	P1.6=0
										KeyValue = 8;break;
							case 0xd0:	//11010000	P1.5=0
										KeyValue = 4;break;
							case 0xe0:	//11100000	P1.4=0
										KeyValue = 0;break;
						}
						break;
			case 0x0d:	//00001101	P1.1=0
						P1 = 0xf0;
						switch(P1)
						{
							case 0x70:	//01110000	P1.7=0
										KeyValue = 13;break;
							case 0xb0:	//10110000	P1.6=0
										KeyValue = 9;break;
							case 0xd0:	//11010000	P1.5=0
										KeyValue = 5;break;
							case 0xe0:	//11100000	P1.4=0
										KeyValue = 1;break;
						}
						break;
			case 0x0b:	//00001011	P1.2=0
						P1 = 0xf0;
						switch(P1)
						{
							case 0x70:	//01110000	P1.7=0
										KeyValue = 14;break;
							case 0xb0:	//10110000	P1.6=0
										KeyValue = 10;break;
							case 0xd0:	//11010000	P1.5=0
										KeyValue = 6;break;
							case 0xe0:	//11100000	P1.4=0
										KeyValue = 2;break;
						}
						break;
			case 0x07:	//00000111	P1.3=0
						P1 = 0xf0;
						switch(P1)
						{
							case 0x70:	//01110000	P1.7=0
										KeyValue = 15;break;
							case 0xb0:	//10110000	P1.6=0
										KeyValue = 11;break;
							case 0xd0:	//11010000	P1.5=0
										KeyValue = 7;break;
							case 0xe0:	//11100000	P1.4=0
										KeyValue = 3;break;
						}
						break;
		}
	}
	return KeyValue;
}

			 
char rn(int y)
{
    if( (y%400==0) || ( (y%4==0)&&(y%100!=0) ) )
        return 29;
    else
        return 28;
}

char judge(int year, char mon)
{
    switch(mon)
    {
        case 4:
        case 6:
        case 9:
        case 11:
                return 30;
        case 2:
                return rn(year);
        default:
                return 31;
    }
}

char i=1;
void timer0(void) interrupt 1
{
    if(++i == 20)
    {
        i = 0;
        if(++second == 60)
        {
            second=0;
            if(++minute == 60)
            {
                minute=0;
                if(++hour==24)
                {
                    hour=0;
                    if( ++day == (judge(2000+year,month)+1) )
                    {
                        day = 1;
                        if(++month==13)
                        {
                            month=1;
                            year++;
                        }
                    }   
                }
            }
        }
    }
}

void main()
{
	char key=0x55;
    TMOD = 0x01;//00000001,T0 mode 1,16bit
    TH0 = -50000/256;
    TL0 = -50000%256;
    ET0 = 1;			 //T0中断允许标志位
    EA = 1;				 //中断允许总标志位
    TR0 = 1;		   	 //T0启动允许标志位
    
    while(1)
    {
		key=KeyScan();
		if(key==1)
		screen1();
		else if(key==2)
		screen2();
    }            
}