程序为什么多跑一次

只看该作者 · 2009-10-14 10:53

程序如下：
while (1)
  {
   /* Loop forever */
   if ( UART0Count != 0 )
   {
         U0IER = IER_THRE | IER_RLS; /* Disable RBR */
         UARTSend( 0, (BYTE*)UART0Buffer, UART0Count );
         UART0Count = 0;
         U0IER = IER_THRE | IER_RLS | IER_RBR; /* Re-enable RBR */
         LCD_gotoxy(1,1);
         LCD_puts(UART0Buffer);
  }
串口程序1
void UARTSend( DWORD portNum, BYTE *BufferPtr, DWORD Length )
{
  WORD i=0;
if ( portNum == 0 )
  {
while ( Length != 0 )
{
/* THRE status, contain valid data */
while ( !(UART0TxEmpty & 0x01) );
U0THR = BufferPtr[i];
UART0TxEmpty = 0; /* not empty in the THR until it shifts out */
  //BufferPtr++;
  Length--;
  i++;
}
  }
  else
  {
while ( Length != 0 )
{
/* THRE status, contain valid data */
while ( !(UART1TxEmpty & 0x01) );
U1THR = BufferPtr[i];
UART1TxEmpty = 0; /* not empty in the THR until it shifts out */
//BufferPtr++;
Length--;
i++;
  }
  }
  return;
}
串口程序2
void UARTSend( DWORD portNum, BYTE *BufferPtr, DWORD Length )
{
  WORD i=0;
if ( portNum == 0 )
  {
while ( Length != 0 )
{
/* THRE status, contain valid data */
while ( !(UART0TxEmpty & 0x01) );
U0THR = *BufferPtr;
UART0TxEmpty = 0; /* not empty in the THR until it shifts out */
  BufferPtr++;
  Length--;
}
  }
  else
  {
while ( Length != 0 )
{
/* THRE status, contain valid data */
while ( !(UART1TxEmpty & 0x01) );
U1THR = *BufferPtr;
UART1TxEmpty = 0; /* not empty in the THR until it shifts out */
BufferPtr++;
Length--;
  }
  }
  return;
}

上面的lcd_puts(char*)
为1602的字符形液晶显示器；
我碰到的问题是，我想串口写段数据，然后在用串口发回pc机，从lcd上显示刚才的字符；
可是在单步调试能正常显示，全速运行后只能显示1个字符，就是最后一个，谁碰到国这个问题？给解释下