哪个大神帮我看看这个产生1K方波的程序哪里出问题了！！

#include<reg51.h>
sbit Start=P2^0;
sbit Stop=P2^1;
sbit output=P1^0;
void Time0_init()
{
TMOD = 0x01;
TH0 = (65535-250)/255;
TL0 = (65535-250)%255;
EA = 1;
ET0 = 1;
TR0 = 1;
}
void Time0() interrupt 1
{
TR0=0;
TH0 = (65535-250)/255;
TL0 = (65535-250)%255;
TR0=1;
output=!output;
}
void main()
{
P1=0x00;
Time0_init();
while(1);
/*while(1)
{
if(Start==0)
{
while(Start==0);
Time0_init();
}
if(Stop==0)
{
while(Stop==0);
TR0=0;
output=0;
}
}*/
}

255改为256，你算下你的初值TH0=256，TH0最大为255，所以编译器应该将TH0为0处理，而TL0算下来很小，所以整个计数值接近于0，即计时65536us，这样方波频率就接近7.5Hz了