2400波特率 发送接收测试都OK ,占用一个定时器

void timer_init()//定时器初始化
{
    _ctm0c0 = 0b00000000;		//16000000/4 =4000,000  
	_ctm0c1 = 0xc1;
	_ctm0al = 0xa0;				
	_ctm0ah = 0x01;
	_ctma0f=0;	
    _ctma0e=1;
	_ct0on = 1;
	_ct0pau = 0;	//
	_emi = 1;
	
}
 
void __attribute((interrupt(0x14))) ctm0(void)
{
	
	_ctma0f=0;
if(RX==0&&Rx_start_bit==0)
{
Rx_start_bit=1;	
RX_start_Receive=1;
j=0;
RI=0;
}
 
if(RX_start_Receive==1)
{
	i_jia++;
	if(i_jia>=4)
{
	i_jia=0;
 
	
		if(j<10)
     {
         Output >>=1;
         if(RX)
         {
         	Output|=0x80;  //先收低位
         }    
         j++;
         
     }	
     if(RX==1&&flah6==1){flah6=0;RX_start_Receive=0;Rx_start_bit=0;RI=1;}
	if(j==9){j=0;receiveByte=Output;flah6=1;}
 
}
 
}
 
if(moni_uart_start==1)  ///发送串口数据
{
	t++;
	if(t>=4)
	{
	t=0;
	if(t1>=8){i=0;moni_uart_start=0;TX=1;t=0;t1=0;jump_first_bit=0;}
	if(jump_first_bit==1)
	{
	   if(i<9)//发送8位数据位
     {   
         if(send_buff&0x01) //先传低位
         {
         	TX=1;
         }
         else
         {	
         	TX=0;
         }
         i++;
        
         send_buff=send_buff>>1;
     } 
      t1++;
	}
    if(send_flrst_bit==0) {i=0;send_flrst_bit=1;TX=0;jump_first_bit=1;send_buff=moni_send_dat;}  //发送启始位
     
	}
	
}
	
	
 
}