原创 请教一个串口收发程序！

实现每接受一个数据，就发送0x01出去的功能，调试出来的结果是：接受到底一个数据，发送出0x01，但是后面 不管接收了多少，没有数据发送出去了。请大家帮我看看，谢谢！源程序 如下：

#include
#include

bit flag;
int i;

InitiateUarts()
{
   //set the RCLK and TCLK to use the Baud Rate Generator for serial 0 and serial 1
   RCLK=1;
   TCLK=1;

   //set the PCON.6/SMOD=0 to make sure that
   //bit 7 of S0CON and S1CON will function as SM0 for UARTs 0 and 1 respectively.
   PCON=0x00;
   
   //disable the multiprocessor communication
   SM2_0=0;
   SM2_1=0;

   //set mode 3 for serial 0
   SM0_0=1;
   SM0_1=1;

   //set mode 3 for serial 1
   SM1_0=1;
   SM1_1=1;

   //enable serial 0 reception
   REN_0=1;
   REN_1=1;

   //set the baud rate to 9600, using Baud Rate Generator
   BRGCON=0x02;
   BRGR0=0xD2;
   BRGR1=0x04;
   BRGCON=0x03;

   //set the priority of serial 0 to the highest level "11"
   PS0=1;  // == IP0.4=1
   IP0H=0x10;  

   //set the priority of serial 1 to the highest level "11"
   PS1=1;
   IP1H=0x01;
  
}

Serial_0() interrupt 6 using 1
{
   if(RI_0)
   {
     flag=1;
     RI_0=0; //clear the flag of serial 0 interrupt
      
   }

}


function()
{
  if(flag)
    {
      S0BUF=0x01;
          flag=0;
           }
        //for(i=0;i<1000;i++);
}

main()
{
   //enable the Uarts 0 and 1 interrupts  
   

   //initiate the uarts 0 and 1
   InitiateUarts();
   EA=1;
   IEN0=0x90;
   IEN1=0x01;


   while(1)
     function();
}

将全局标志bit flag;
改为:volatile bit flag;

参见帖子:http://bbs.21ic.com/club/bbs/ShowAnnounce.asp?id=2414907