以一秒為例，給你寫了一個程式，自己看吧，修改TH0、TL0和count就可以設定任意時間間隔閃爍了

#include <reg51.h>

#define uchar unsigned char

#define uint unsigned int

sbit LED=P1^0;

bit flag;

uchar count=0;

void delay(uchar c)

{

uchar a, b;

for (; c>0;c--)

for (b=142;b>0;b--)

for (a=2; a>0; a--);

}

void main(void)

{

TMOD=0x01;

TH0=(65536-50000)/256;

TL0=(65536-50000)%256;

EA=1;

ET0=1;

TR0=1;

while(1)

{

if(flag==1)

{

LED=0;

delay(100);

LED=1;

flag=0;

}

}

}

void time0(void) interrupt 1

{

TH0=(65536-50000)/256;

TL0=(65536-50000)%256;

count++;

if (count>=20)

{

count=0;

flag=1;

}