starterware的NAND

使用starterware中的OMAPL138_StarterWare_1_10_03_03examplesevmOMAPL138nand的 工程，编译没错误，下载后运行，到调用drivers中的uart.c中的 UARTCharPut
/**
 * brief   This function checks indefinitely whether the Transmitter FIFO
 *          (THR regsiter in non-FIFO mode)is empty. If found empty, a byte
 *          is written into the THR register.
 *
 * param   baseAdd         Memory address of the UART instance being used.
 * param   byteTx          Byte to be transmitted.
 *
 * return  None.
 *
 */

void UARTCharPut(unsigned int baseAdd, unsigned char byteTx)
[
   unsigned int txEmpty;
   txEmpty = (UART_THR_TSR_EMPTY | UART_THR_EMPTY);
   /*
   ** Here we check for the emptiness of both the Trasnsmitter Holding
   ** Register(THR) and Transmitter Shift Register(TSR) before writing
   ** data into the Transmitter FIFO(THR for non-FIFO mode).
   */
  
   while (txEmpty != (HWREG(baseAdd + UART_LSR) & txEmpty));
  
   /*
   ** Transmitter FIFO(THR register in non-FIFO mode) is empty.
   ** Write the byte onto the THR register.
   */
   HWREG(baseAdd + UART_THR) = byteTx;
]
到这一句时候   while (txEmpty != (HWREG(baseAdd + UART_LSR) & txEmpty));
就停了，不知道什么原因，希望能帮我看看，谢谢