单片机笔记_定时器中

#include<reg52.h>

int a = 0xf0;

unsigned char cnt;

sbit p1_0 = P1^0;

void main()

{

//IT0 = 1; //TCON寄存器的第0位,头文件已定义sbit IT0 = TCON^0;

EA = 1;  //EA = IE^7;  

ET1 = 1;

TMOD = 0x10; //00110000 定时器1工作方式1，16位计数

//EX0 = 1;

TH1 = (65536 - 50000) / 256;

TL1 = (65536 - 50000) % 256;

TR1 = 1;

cnt = 0;

while(1)

{

if(cnt == 20)

{

p1_0 = ~p1_0;

cnt = 0;

}

}

}

void ext0() interrupt 3   //[using n],使用第几组寄存器.没加using的话，自动分配寄存器.

{

TH1 = (65536 - 50000) / 256;

TL1 = (65536 - 50000) % 256;   

cnt++;

}