text: /* ----------------------------------------------------------------------------
   *         ATMEL Microcontroller Software Support 
   * ----------------------------------------------------------------------------
   * Copyright (c) 2008, Atmel Corporation
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * - Redistributions of source code must retain the above copyright
   *   notice, this list of conditions and the following disclaimer.
   * - Redistributions in binary form must reproduce the above copyright
   *   notice, this list of conditions and the following disclaimer in the
   *   documentation and/or other materials provided with the
   *   distribution.
   * - Neither the name of the copyright holders nor the names of its
   *   contributors may be used to endorse or promote products derived
   *   from this software without specific prior written permission.
   *
   * Atmel's name may not be used to endorse or promote products derived from
   * this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT
   * HOLDER OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
   * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
   * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
   * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
   * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
   * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   * ----------------------------------------------------------------------------
   */
  
  //------------------------------------------------------------------------------
  //         Headers
  //------------------------------------------------------------------------------
  
  #include "dbgu.h"
  #include <board.h>
  
  //------------------------------------------------------------------------------
  //         Global functions
  //------------------------------------------------------------------------------
  //------------------------------------------------------------------------------
  /// Initializes the DBGU with the given parameters, and enables both the
  /// transmitter and the receiver. The mode parameter contains the value of the
  /// DBGU_MR register.
  /// Value DBGU_STANDARD can be used for mode to get the most common configuration
  /// (i.e. aysnchronous, 8bits, no parity, 1 stop bit, no flow control).
  /// \param mode  Operating mode to configure.
  /// \param baudrate  Desired baudrate (e.g. 115200).
  /// \param mck  Frequency of the system master clock in Hz.
  //------------------------------------------------------------------------------
  void DBGU_Configure(
      unsigned int mode,
      unsigned int baudrate,
      unsigned int mck)
  {
      #if defined(cortexm3)
      // Enable clock for UART
      AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_DBGU);
      #endif
  
      // Reset & disable receiver and transmitter, disable interrupts
      AT91C_BASE_DBGU->DBGU_CR = AT91C_US_RSTRX | AT91C_US_RSTTX;
      AT91C_BASE_DBGU->DBGU_IDR = 0xFFFFFFFF;
      
      // Configure baud rate
      AT91C_BASE_DBGU->DBGU_BRGR = mck / (baudrate * 16);
      
      // Configure mode register
      AT91C_BASE_DBGU->DBGU_MR = mode;
      
      // Disable DMA channel
      AT91C_BASE_DBGU->DBGU_PTCR = AT91C_PDC_RXTDIS | AT91C_PDC_TXTDIS;
  
      // Enable receiver and transmitter
      AT91C_BASE_DBGU->DBGU_CR = AT91C_US_RXEN | AT91C_US_TXEN;
  }
  
  //------------------------------------------------------------------------------
  /// Outputs a character on the DBGU line.
  /// \note This function is synchronous (i.e. uses polling).
  /// \param c  Character to send.
  //------------------------------------------------------------------------------
  void DBGU_PutChar(unsigned char c)
  {
      // Wait for the transmitter to be ready
      while ((AT91C_BASE_DBGU->DBGU_CSR & AT91C_US_TXEMPTY) == 0);
      
      // Send character
      AT91C_BASE_DBGU->DBGU_THR = c;
      
      // Wait for the transfer to complete
      while ((AT91C_BASE_DBGU->DBGU_CSR & AT91C_US_TXEMPTY) == 0);
  }
  
  //------------------------------------------------------------------------------
  /// Return 1 if a character can be read in DBGU
  //------------------------------------------------------------------------------
  unsigned int DBGU_IsRxReady()
  {
      return (AT91C_BASE_DBGU->DBGU_CSR & AT91C_US_RXRDY);
  }
  
  //------------------------------------------------------------------------------
  /// Reads and returns a character from the DBGU.
  /// \note This function is synchronous (i.e. uses polling).
  /// \return Character received.
  //------------------------------------------------------------------------------
  unsigned char DBGU_GetChar(void)
  {
      while ((AT91C_BASE_DBGU->DBGU_CSR & AT91C_US_RXRDY) == 0);
      return AT91C_BASE_DBGU->DBGU_RHR;
  }
  
  
  
  