}
void main()
{
TMOD = 0x01 ; /*定时器工作在方式3*/
EA = 1; /*开总中断*/
ET0 = 1; /*开定时器中断*/
TR0 = 1;
p1 = 0xff;
while(1)
{
NHZ =(~p1)&0x07;
if(NHZ != 0)
{
TIME = 0x10000 - 0x7a1/NHZ;
TH0 = (DD = TIME> > 8)&0xff;
TL0 = (DD = TIME < <8)&0xff;
while(1)
{
i = 0;
do
{
i++;
do
{}while(1);
}while(i <255);
j = 255;
do
{
j--;
do
{}while(1);
}while(j <0);
}
}
}
}