title: LPC UART receive issue
body: <p>I have a problem with UART RX FIFO. If I power up my UART peripheral I receive a RXFE error in my LSR register, UART TX works well. </p>
  
  <p>I use LPC4088 with 120MHz PCLK and 115200Baud</p>
  
  <p>I tried to read the register to clear the pending error but without success. Hope some of you can help.</p>
  
  <pre><code>
  void UART3_Init(void){
      LPC_SYSCTL-&gt;PCONP |= (1 &lt;&lt; 25);                 // Enable Power &amp; CLock for UART3
      LPC_UART3-&gt;LCR = (3 &lt;&lt; 0)                   // Word Length: 8 Bit
              |(0 &lt;&lt; 2)                   // Stop Bit: 1 Bit
              |(0 &lt;&lt; 3)                   // Parity Enable: disabled
              |(1 &lt;&lt; 7);                  // Divisor Latch: enabled
      LPC_UART3-&gt;DLL = 65;                        // Divisor Latch: 65 for 115200 Baud
      LPC_UART3-&gt;DLM = 0;                     // Divisor Latch: 0 for 115200 Baud
      LPC_UART3-&gt;FCR = (1 &lt;&lt; 0)                   // FIFO enable: enabled
              |(1 &lt;&lt; 1)                   // RX FIFO reset: enabled
              |(1 &lt;&lt; 2);                  // TX FIFO reset: enabled
      LPC_UART3-&gt;FDR = (0 &lt;&lt; 0)                   // Baudrate prescaler Value: DIVADDL = 0
              |(1 &lt;&lt; 4);                  // Baudrate prescaler Value: MULVAL = 1
      LPC_UART3-&gt;LCR &amp;= ~(1 &lt;&lt; 7);                    // disable to lock Baud - without this no UART communication
  }
  
  
  char UART3_receive(void){
      while(!(LPC_UART3-&gt;LSR &amp; (1 &lt;&lt; 0)));                //wait until data arrives in Rx FIFO
      return LPC_UART3-&gt;RBR;
  }
  
  int main(void){
      CCLK runs with 120MHz
  
      //UART 3 Pins
      LPC_IOCON-&gt;p[0][25] = (3 &lt;&lt; 0);         //UART3 TX  p[0][25]
      LPC_GPIO-&gt;DIR = (1 &lt;&lt; 25);
      LPC_IOCON-&gt;p[0][26] = (3 &lt;&lt; 0);         //UART3 RX  p[0][26]
      LPC_GPIO-&gt;DIR = (0 &lt;&lt; 26);
  
      UART3_Init();
  
      char data = 0;
  
      while(1){
          data = UART3_receive();
  
          if(data == ENTER){
              //PRINT back to terminal "SUCCESS"
              ...
              ...
          }
      }
  }
  </code></pre>