#include

typedef unsigned char u8;

typedef unsigned int u16;

sbit led = P1^0;

u8 timer;

void main (void)

{

TMOD = 0x01;//設置TMOD，使得T0工作在16位定時。

TH0 = (65535-50000) / 256;

TL0 = (65535-50000) % 256;

EA = 1; //開放總中斷

ET0 = 1;//開放定時器0的溢出中斷

TR0 = 1;//開始定時

while(1) //作用就是讓程序結束 否則程序一直在這運行;

{

;

}

}

//實現(xiàn)方式一

void timer0_service(void) interrupt 1

{

TH0 = (65535-50000) / 256;

TL0 = (65535-50000) % 256;

//50ms已經(jīng)設置好了

timer ++;

if (timer == 20)

{

timer = 0;

led = ~led;

}

}