#include "pic1687x.h"
void interrupt IRQ(void)
{
     TMR1IF = 0;
     TMR1ON=0;
     TMR1H=0xff;
     TMR1L=0x00;
     TMR1ON=1;
     RB1=!RB1；   
}
void main(void)
{
  TMR1H=0xff;
  TMR1L=0x00; // 加载定时计数初值
  TMR1IF = 0;//定时器溢出标志要清零
  TMR1IE = 1;//中断始能
  //PEIE=1;//外部中断源使能
  TMR1IE=1;//定时器1中断容许
  T1CKPS0=1;//分频
  T1CKPS1=1;
  T1OSCEN=0; //不使用振荡器
  TMR1CS=0;  //内部时钟源
  TMR1ON=1;  //开定时器1中断
  GIE=1;//开中断
  TRISB=0;//端口0输出
  
}