单片机期末考试编程题(18)

{

unsigned char i=0,n=0; n=number;

for(i=0;i<4;i++) {

num[i]=n%2; n=n/2; }

led0=!num[0];

led1=!num[1];

led2=!num[2];

led3=!num[3];

}

void main()

{

init();

while(1)

{

key();

if(flag==0) TR0=1; else

TR0=0;

num_change(); }

}

void time0() interrupt 1 {

TH0=(65536-50000)%256; TL0=(65536-50000)/256; k++;

if(k>19)

{

number++; if(number>15) number=0; k=0;

}

}