定时器 下列程序就是超过30S 单片机进入掉电模式的例程
unsigned char ct,Free_time;
void main()
{
while(1)
{
if(Free_time > 30)
{
PCON = 0x02; //进入掉电模式
}
}
}
void ext0() interrupt 0
{
Free_time = 0;
}
void t0() interrupt 1
{
TH0 = (65536 - 50000) >> 8;
TL0 = (65536 - 50000)&0xff;
ct++;
if(ct > 19)
{
ct = 0;
Free_time ++;
}
}