利用單片機設計實現壹個60秒倒計時顯示裝置，並且計時到後發出報警聲音。

sbit?bz=P3^1;

unsigned?char?a[10]={0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,0xd8,0x80,0x90};

unsigned?char?n,time=60;

main()

{

P1=a[0];

P2=a[6];

TMOD=0X01;

TH0=(65536-10000)/256;

TL0=(65536-10000)%256;

EA=1;

ET0=1;

TR0=1;

while(1);

}

timer0()?interrupt?1

{

TH0=(65536-10000)/256;

TL0=(65536-10000)%256;

if(time!=0)

{

n++;

if(n==100)

{

n=0;

time--;

P1=a[time%10];

P2=a[time/10];

}

}

else?bz=~bz;

}