Merged upstream arduino branch

2 files changed, 1803 insertions, 0 deletions

diff --git a/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/USART/usart.c b/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/USART/usart.c
new file mode 100644
index 0000000..b95882a
--- /dev/null
+++ b/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/USART/usart.c
@@ -0,0 +1,914 @@
+/* This source file is part of the ATMEL AVR-UC3-SoftwareFramework-1.7.0 Release */
+
+/*This file is prepared for Doxygen automatic documentation generation.*/
+/*! \file *********************************************************************
+ *
+ * \brief USART driver for AVR32 UC3.
+ *
+ * This file contains basic functions for the AVR32 USART, with support for all
+ * modes, settings and clock speeds.
+ *
+ * - Compiler:           IAR EWAVR32 and GNU GCC for AVR32
+ * - Supported devices:  All AVR32 devices with a USART module can be used.
+ * - AppNote:
+ *
+ * \author               Atmel Corporation: http://www.atmel.com \n
+ *                       Support and FAQ: http://support.atmel.no/
+ *
+ ******************************************************************************/
+
+/* Copyright (c) 2009 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:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an Atmel
+ * AVR product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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
+ *
+ */
+
+#include "compiler.h"
+#include "usart.h"
+
+
+//------------------------------------------------------------------------------
+/*! \name Private Functions
+ */
+//! @{
+
+
+/*! \brief Checks if the USART is in multidrop mode.
+ *
+ * \param usart Base address of the USART instance.
+ *
+ * \return \c 1 if the USART is in multidrop mode, otherwise \c 0.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+static __inline__ int usart_mode_is_multidrop(volatile avr32_usart_t *usart)
+{
+  return ((usart->mr >> AVR32_USART_MR_PAR_OFFSET) & AVR32_USART_MR_PAR_MULTI) == AVR32_USART_MR_PAR_MULTI;
+}
+
+
+/*! \brief Calculates a clock divider (\e CD) and a fractional part (\e FP) for
+ *         the USART asynchronous modes to generate a baud rate as close as
+ *         possible to the baud rate set point.
+ *
+ * Baud rate calculation:
+ * \f$ Baudrate = \frac{SelectedClock}{Over \times (CD + \frac{FP}{8})} \f$, \e Over being 16 or 8.
+ * The maximal oversampling is selected if it allows to generate a baud rate close to the set point.
+ *
+ * \param usart     Base address of the USART instance.
+ * \param baudrate  Baud rate set point.
+ * \param pba_hz    USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Baud rate successfully initialized.
+ * \retval USART_INVALID_INPUT  Baud rate set point is out of range for the given input clock frequency.
+ */
+static int usart_set_async_baudrate(volatile avr32_usart_t *usart, unsigned int baudrate, unsigned long pba_hz)
+{
+  unsigned int over = (pba_hz >= 16 * baudrate) ? 16 : 8;
+  unsigned int cd_fp = ((1 << AVR32_USART_BRGR_FP_SIZE) * pba_hz + (over * baudrate) / 2) / (over * baudrate);
+  unsigned int cd = cd_fp >> AVR32_USART_BRGR_FP_SIZE;
+  unsigned int fp = cd_fp & ((1 << AVR32_USART_BRGR_FP_SIZE) - 1);
+
+  if (cd < 1 || cd > (1 << AVR32_USART_BRGR_CD_SIZE) - 1)
+    return USART_INVALID_INPUT;
+
+  usart->mr = (usart->mr & ~(AVR32_USART_MR_USCLKS_MASK |
+                             AVR32_USART_MR_SYNC_MASK |
+                             AVR32_USART_MR_OVER_MASK)) |
+              AVR32_USART_MR_USCLKS_MCK << AVR32_USART_MR_USCLKS_OFFSET |
+              ((over == 16) ? AVR32_USART_MR_OVER_X16 : AVR32_USART_MR_OVER_X8) << AVR32_USART_MR_OVER_OFFSET;
+
+  usart->brgr = cd << AVR32_USART_BRGR_CD_OFFSET |
+                fp << AVR32_USART_BRGR_FP_OFFSET;
+
+  return USART_SUCCESS;
+}
+
+
+/*! \brief Calculates a clock divider (\e CD) for the USART synchronous master
+ *         modes to generate a baud rate as close as possible to the baud rate
+ *         set point.
+ *
+ * Baud rate calculation:
+ * \f$ Baudrate = \frac{SelectedClock}{CD} \f$.
+ *
+ * \param usart     Base address of the USART instance.
+ * \param baudrate  Baud rate set point.
+ * \param pba_hz    USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Baud rate successfully initialized.
+ * \retval USART_INVALID_INPUT  Baud rate set point is out of range for the given input clock frequency.
+ */
+static int usart_set_sync_master_baudrate(volatile avr32_usart_t *usart, unsigned int baudrate, unsigned long pba_hz)
+{
+  unsigned int cd = (pba_hz + baudrate / 2) / baudrate;
+
+  if (cd < 1 || cd > (1 << AVR32_USART_BRGR_CD_SIZE) - 1)
+    return USART_INVALID_INPUT;
+
+  usart->mr = (usart->mr & ~AVR32_USART_MR_USCLKS_MASK) |
+              AVR32_USART_MR_USCLKS_MCK << AVR32_USART_MR_USCLKS_OFFSET |
+              AVR32_USART_MR_SYNC_MASK;
+
+  usart->brgr = cd << AVR32_USART_BRGR_CD_OFFSET;
+
+  return USART_SUCCESS;
+}
+
+
+/*! \brief Selects the SCK pin as the source of baud rate for the USART
+ *         synchronous slave modes.
+ *
+ * \param usart Base address of the USART instance.
+ *
+ * \retval USART_SUCCESS  Baud rate successfully initialized.
+ */
+static int usart_set_sync_slave_baudrate(volatile avr32_usart_t *usart)
+{
+  usart->mr = (usart->mr & ~AVR32_USART_MR_USCLKS_MASK) |
+              AVR32_USART_MR_USCLKS_SCK << AVR32_USART_MR_USCLKS_OFFSET |
+              AVR32_USART_MR_SYNC_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+/*! \brief Calculates a clock divider (\e CD) for the USART ISO7816 mode to
+ *         generate an ISO7816 clock as close as possible to the clock set point.
+ *
+ * ISO7816 clock calculation:
+ * \f$ Clock = \frac{SelectedClock}{CD} \f$.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param clock   ISO7816 clock set point.
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        ISO7816 clock successfully initialized.
+ * \retval USART_INVALID_INPUT  ISO7816 clock set point is out of range for the given input clock frequency.
+ */
+static int usart_set_iso7816_clock(volatile avr32_usart_t *usart, unsigned int clock, unsigned long pba_hz)
+{
+  unsigned int cd = (pba_hz + clock / 2) / clock;
+
+  if (cd < 1 || cd > (1 << AVR32_USART_BRGR_CD_SIZE) - 1)
+    return USART_INVALID_INPUT;
+
+  usart->mr = (usart->mr & ~(AVR32_USART_MR_USCLKS_MASK |
+                             AVR32_USART_MR_SYNC_MASK |
+                             AVR32_USART_MR_OVER_MASK)) |
+              AVR32_USART_MR_USCLKS_MCK << AVR32_USART_MR_USCLKS_OFFSET |
+              AVR32_USART_MR_OVER_X16 << AVR32_USART_MR_OVER_OFFSET;
+
+  usart->brgr = cd << AVR32_USART_BRGR_CD_OFFSET;
+
+  return USART_SUCCESS;
+}
+
+
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+
+/*! \brief Calculates a clock divider (\e CD) for the USART SPI master mode to
+ *         generate a baud rate as close as possible to the baud rate set point.
+ *
+ * Baud rate calculation:
+ * \f$ Baudrate = \frac{SelectedClock}{CD} \f$.
+ *
+ * \param usart     Base address of the USART instance.
+ * \param baudrate  Baud rate set point.
+ * \param pba_hz    USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Baud rate successfully initialized.
+ * \retval USART_INVALID_INPUT  Baud rate set point is out of range for the given input clock frequency.
+ */
+static int usart_set_spi_master_baudrate(volatile avr32_usart_t *usart, unsigned int baudrate, unsigned long pba_hz)
+{
+  unsigned int cd = (pba_hz + baudrate / 2) / baudrate;
+
+  if (cd < 4 || cd > (1 << AVR32_USART_BRGR_CD_SIZE) - 1)
+    return USART_INVALID_INPUT;
+
+  usart->mr = (usart->mr & ~AVR32_USART_MR_USCLKS_MASK) |
+              AVR32_USART_MR_USCLKS_MCK << AVR32_USART_MR_USCLKS_OFFSET;
+
+  usart->brgr = cd << AVR32_USART_BRGR_CD_OFFSET;
+
+  return USART_SUCCESS;
+}
+
+
+/*! \brief Selects the SCK pin as the source of baud rate for the USART SPI
+ *         slave mode.
+ *
+ * \param usart Base address of the USART instance.
+ *
+ * \retval USART_SUCCESS  Baud rate successfully initialized.
+ */
+static int usart_set_spi_slave_baudrate(volatile avr32_usart_t *usart)
+{
+  usart->mr = (usart->mr & ~AVR32_USART_MR_USCLKS_MASK) |
+              AVR32_USART_MR_USCLKS_SCK << AVR32_USART_MR_USCLKS_OFFSET;
+
+  return USART_SUCCESS;
+}
+
+
+#endif  // USART rev. >= 4.0.0
+
+
+//! @}
+
+
+//------------------------------------------------------------------------------
+/*! \name Initialization Functions
+ */
+//! @{
+
+
+void usart_reset(volatile avr32_usart_t *usart)
+{
+  Bool global_interrupt_enabled = Is_global_interrupt_enabled();
+
+  // Disable all USART interrupts.
+  // Interrupts needed should be set explicitly on every reset.
+  if (global_interrupt_enabled) Disable_global_interrupt();
+  usart->idr = 0xFFFFFFFF;
+  usart->csr;
+  if (global_interrupt_enabled) Enable_global_interrupt();
+
+  // Reset mode and other registers that could cause unpredictable behavior after reset.
+  usart->mr = 0;
+  usart->rtor = 0;
+  usart->ttgr = 0;
+
+  // Shutdown TX and RX (will be re-enabled when setup has successfully completed),
+  // reset status bits and turn off DTR and RTS.
+  usart->cr = AVR32_USART_CR_RSTRX_MASK   |
+              AVR32_USART_CR_RSTTX_MASK   |
+              AVR32_USART_CR_RSTSTA_MASK  |
+              AVR32_USART_CR_RSTIT_MASK   |
+              AVR32_USART_CR_RSTNACK_MASK |
+#ifndef AVR32_USART_440_H_INCLUDED
+// Note: Modem Signal Management DTR-DSR-DCD-RI are not included in USART rev.440.
+              AVR32_USART_CR_DTRDIS_MASK  |
+#endif
+              AVR32_USART_CR_RTSDIS_MASK;
+}
+
+
+int usart_init_rs232(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz)
+{
+  // Reset the USART and shutdown TX and RX.
+  usart_reset(usart);
+
+  // Check input values.
+  if (!opt || // Null pointer.
+      opt->charlength < 5 || opt->charlength > 9 ||
+      opt->paritytype > 7 ||
+      opt->stopbits > 2 + 255 ||
+      opt->channelmode > 3 ||
+      usart_set_async_baudrate(usart, opt->baudrate, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  if (opt->charlength == 9)
+  {
+    // Character length set to 9 bits. MODE9 dominates CHRL.
+    usart->mr |= AVR32_USART_MR_MODE9_MASK;
+  }
+  else
+  {
+    // CHRL gives the character length (- 5) when MODE9 = 0.
+    usart->mr |= (opt->charlength - 5) << AVR32_USART_MR_CHRL_OFFSET;
+  }
+
+  usart->mr |= opt->paritytype << AVR32_USART_MR_PAR_OFFSET |
+               opt->channelmode << AVR32_USART_MR_CHMODE_OFFSET;
+
+  if (opt->stopbits > USART_2_STOPBITS)
+  {
+    // Set two stop bits
+    usart->mr |= AVR32_USART_MR_NBSTOP_2 << AVR32_USART_MR_NBSTOP_OFFSET;
+    // and a timeguard period gives the rest.
+    usart->ttgr = opt->stopbits - USART_2_STOPBITS;
+  }
+  else
+    // Insert 1, 1.5 or 2 stop bits.
+    usart->mr |= opt->stopbits << AVR32_USART_MR_NBSTOP_OFFSET;
+
+  // Set normal mode.
+  usart->mr = (usart->mr & ~AVR32_USART_MR_MODE_MASK) |
+              AVR32_USART_MR_MODE_NORMAL << AVR32_USART_MR_MODE_OFFSET;
+
+  // Setup complete; enable communication.
+  // Enable input and output.
+  usart->cr = AVR32_USART_CR_RXEN_MASK |
+              AVR32_USART_CR_TXEN_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_rs232_tx_only(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz)
+{
+  // Reset the USART and shutdown TX and RX.
+  usart_reset(usart);
+
+  // Check input values.
+  if (!opt || // Null pointer.
+      opt->charlength < 5 || opt->charlength > 9 ||
+      opt->paritytype > 7 ||
+      opt->stopbits == 1 || opt->stopbits > 2 + 255 ||
+      opt->channelmode > 3 ||
+      usart_set_sync_master_baudrate(usart, opt->baudrate, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  if (opt->charlength == 9)
+  {
+    // Character length set to 9 bits. MODE9 dominates CHRL.
+    usart->mr |= AVR32_USART_MR_MODE9_MASK;
+  }
+  else
+  {
+    // CHRL gives the character length (- 5) when MODE9 = 0.
+    usart->mr |= (opt->charlength - 5) << AVR32_USART_MR_CHRL_OFFSET;
+  }
+
+  usart->mr |= opt->paritytype << AVR32_USART_MR_PAR_OFFSET |
+               opt->channelmode << AVR32_USART_MR_CHMODE_OFFSET;
+
+  if (opt->stopbits > USART_2_STOPBITS)
+  {
+    // Set two stop bits
+    usart->mr |= AVR32_USART_MR_NBSTOP_2 << AVR32_USART_MR_NBSTOP_OFFSET;
+    // and a timeguard period gives the rest.
+    usart->ttgr = opt->stopbits - USART_2_STOPBITS;
+  }
+  else
+    // Insert 1 or 2 stop bits.
+    usart->mr |= opt->stopbits << AVR32_USART_MR_NBSTOP_OFFSET;
+
+  // Set normal mode.
+  usart->mr = (usart->mr & ~AVR32_USART_MR_MODE_MASK) |
+              AVR32_USART_MR_MODE_NORMAL << AVR32_USART_MR_MODE_OFFSET;
+
+  // Setup complete; enable communication.
+  // Enable only output as input is not possible in synchronous mode without
+  // transferring clock.
+  usart->cr = AVR32_USART_CR_TXEN_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_hw_handshaking(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz)
+{
+  // First: Setup standard RS232.
+  if (usart_init_rs232(usart, opt, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  // Set hardware handshaking mode.
+  usart->mr = (usart->mr & ~AVR32_USART_MR_MODE_MASK) |
+              AVR32_USART_MR_MODE_HARDWARE << AVR32_USART_MR_MODE_OFFSET;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_modem(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz)
+{
+  // First: Setup standard RS232.
+  if (usart_init_rs232(usart, opt, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  // Set modem mode.
+  usart->mr = (usart->mr & ~AVR32_USART_MR_MODE_MASK) |
+              AVR32_USART_MR_MODE_MODEM << AVR32_USART_MR_MODE_OFFSET;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_sync_master(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz)
+{
+  // Reset the USART and shutdown TX and RX.
+  usart_reset(usart);
+
+  // Check input values.
+  if (!opt || // Null pointer.
+      opt->charlength < 5 || opt->charlength > 9 ||
+      opt->paritytype > 7 ||
+      opt->stopbits == 1 || opt->stopbits > 2 + 255 ||
+      opt->channelmode > 3 ||
+      usart_set_sync_master_baudrate(usart, opt->baudrate, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  if (opt->charlength == 9)
+  {
+    // Character length set to 9 bits. MODE9 dominates CHRL.
+    usart->mr |= AVR32_USART_MR_MODE9_MASK;
+  }
+  else
+  {
+    // CHRL gives the character length (- 5) when MODE9 = 0.
+    usart->mr |= (opt->charlength - 5) << AVR32_USART_MR_CHRL_OFFSET;
+  }
+
+  usart->mr |= opt->paritytype << AVR32_USART_MR_PAR_OFFSET |
+               opt->channelmode << AVR32_USART_MR_CHMODE_OFFSET;
+
+  if (opt->stopbits > USART_2_STOPBITS)
+  {
+    // Set two stop bits
+    usart->mr |= AVR32_USART_MR_NBSTOP_2 << AVR32_USART_MR_NBSTOP_OFFSET;
+    // and a timeguard period gives the rest.
+    usart->ttgr = opt->stopbits - USART_2_STOPBITS;
+  }
+  else
+    // Insert 1 or 2 stop bits.
+    usart->mr |= opt->stopbits << AVR32_USART_MR_NBSTOP_OFFSET;
+
+  // Set normal mode.
+  usart->mr = (usart->mr & ~AVR32_USART_MR_MODE_MASK) |
+              AVR32_USART_MR_MODE_NORMAL << AVR32_USART_MR_MODE_OFFSET |
+              AVR32_USART_MR_CLKO_MASK;
+
+  // Setup complete; enable communication.
+  // Enable input and output.
+  usart->cr = AVR32_USART_CR_RXEN_MASK |
+              AVR32_USART_CR_TXEN_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_sync_slave(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz)
+{
+  // Reset the USART and shutdown TX and RX.
+  usart_reset(usart);
+
+  // Check input values.
+  if (!opt || // Null pointer.
+      opt->charlength < 5 || opt->charlength > 9 ||
+      opt->paritytype > 7 ||
+      opt->stopbits == 1 || opt->stopbits > 2 + 255 ||
+      opt->channelmode > 3 ||
+      usart_set_sync_slave_baudrate(usart) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  if (opt->charlength == 9)
+  {
+    // Character length set to 9 bits. MODE9 dominates CHRL.
+    usart->mr |= AVR32_USART_MR_MODE9_MASK;
+  }
+  else
+  {
+    // CHRL gives the character length (- 5) when MODE9 = 0.
+    usart->mr |= (opt->charlength - 5) << AVR32_USART_MR_CHRL_OFFSET;
+  }
+
+  usart->mr |= opt->paritytype << AVR32_USART_MR_PAR_OFFSET |
+               opt->channelmode << AVR32_USART_MR_CHMODE_OFFSET;
+
+  if (opt->stopbits > USART_2_STOPBITS)
+  {
+    // Set two stop bits
+    usart->mr |= AVR32_USART_MR_NBSTOP_2 << AVR32_USART_MR_NBSTOP_OFFSET;
+    // and a timeguard period gives the rest.
+    usart->ttgr = opt->stopbits - USART_2_STOPBITS;
+  }
+  else
+    // Insert 1 or 2 stop bits.
+    usart->mr |= opt->stopbits << AVR32_USART_MR_NBSTOP_OFFSET;
+
+  // Set normal mode.
+  usart->mr = (usart->mr & ~AVR32_USART_MR_MODE_MASK) |
+              AVR32_USART_MR_MODE_NORMAL << AVR32_USART_MR_MODE_OFFSET;
+
+  // Setup complete; enable communication.
+  // Enable input and output.
+  usart->cr = AVR32_USART_CR_RXEN_MASK |
+              AVR32_USART_CR_TXEN_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_rs485(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz)
+{
+  // First: Setup standard RS232.
+  if (usart_init_rs232(usart, opt, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  // Set RS485 mode.
+  usart->mr = (usart->mr & ~AVR32_USART_MR_MODE_MASK) |
+              AVR32_USART_MR_MODE_RS485 << AVR32_USART_MR_MODE_OFFSET;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_IrDA(volatile avr32_usart_t *usart, const usart_options_t *opt,
+                    long pba_hz, unsigned char irda_filter)
+{
+  // First: Setup standard RS232.
+  if (usart_init_rs232(usart, opt, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  // Set IrDA filter.
+  usart->ifr = irda_filter;
+
+  // Set IrDA mode and activate filtering of input.
+  usart->mr = (usart->mr & ~AVR32_USART_MR_MODE_MASK) |
+              AVR32_USART_MODE_IRDA << AVR32_USART_MR_MODE_OFFSET |
+              AVR32_USART_MR_FILTER_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_iso7816(volatile avr32_usart_t *usart, const usart_iso7816_options_t *opt, int t, long pba_hz)
+{
+  // Reset the USART and shutdown TX and RX.
+  usart_reset(usart);
+
+  // Check input values.
+  if (!opt || // Null pointer.
+      opt->paritytype > 1)
+    return USART_INVALID_INPUT;
+
+  if (t == 0)
+  {
+    // Set USART mode to ISO7816, T=0.
+    // The T=0 protocol always uses 2 stop bits.
+    usart->mr = AVR32_USART_MR_MODE_ISO7816_T0 << AVR32_USART_MR_MODE_OFFSET |
+                AVR32_USART_MR_NBSTOP_2 << AVR32_USART_MR_NBSTOP_OFFSET |
+                opt->bit_order << AVR32_USART_MR_MSBF_OFFSET; // Allow MSBF in T=0.
+  }
+  else if (t == 1)
+  {
+    // Only LSB first in the T=1 protocol.
+    // max_iterations field is only used in T=0 mode.
+    if (opt->bit_order != 0 ||
+        opt->max_iterations != 0)
+      return USART_INVALID_INPUT;
+
+    // Set USART mode to ISO7816, T=1.
+    // The T=1 protocol always uses 1 stop bit.
+    usart->mr = AVR32_USART_MR_MODE_ISO7816_T1 << AVR32_USART_MR_MODE_OFFSET |
+                AVR32_USART_MR_NBSTOP_1 << AVR32_USART_MR_NBSTOP_OFFSET;
+  }
+  else
+    return USART_INVALID_INPUT;
+
+  if (usart_set_iso7816_clock(usart, opt->iso7816_hz, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  // Set FIDI register: bit rate = selected clock/FI_DI_ratio/16.
+  usart->fidi = opt->fidi_ratio;
+
+  // Set ISO7816 spesific options in the MODE register.
+  usart->mr |= opt->paritytype << AVR32_USART_MR_PAR_OFFSET |
+               AVR32_USART_MR_CLKO_MASK | // Enable clock output.
+               opt->inhibit_nack << AVR32_USART_MR_INACK_OFFSET |
+               opt->dis_suc_nack << AVR32_USART_MR_DSNACK_OFFSET |
+               opt->max_iterations << AVR32_USART_MR_MAX_ITERATION_OFFSET;
+
+  // Setup complete; enable the receiver by default.
+  usart_iso7816_enable_receiver(usart);
+
+  return USART_SUCCESS;
+}
+
+
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+
+int usart_init_lin_master(volatile avr32_usart_t *usart, unsigned long baudrate, long pba_hz)
+{
+  // Reset the USART and shutdown TX and RX.
+  usart_reset(usart);
+
+  // Check input values.
+  if (usart_set_async_baudrate(usart, baudrate, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  usart->mr |= AVR32_USART_MR_MODE_LIN_MASTER << AVR32_USART_MR_MODE_OFFSET;  // LIN master mode.
+
+  // Setup complete; enable communication.
+  // Enable input and output.
+  usart->cr = AVR32_USART_CR_RXEN_MASK |
+              AVR32_USART_CR_TXEN_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_lin_slave(volatile avr32_usart_t *usart, unsigned long baudrate, long pba_hz)
+{
+  // Reset the USART and shutdown TX and RX.
+  usart_reset(usart);
+
+  // Check input values.
+  if (usart_set_async_baudrate(usart, baudrate, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  usart->mr |= AVR32_USART_MR_MODE_LIN_SLAVE << AVR32_USART_MR_MODE_OFFSET; // LIN slave mode.
+
+  // Setup complete; enable communication.
+  // Enable input and output.
+  usart->cr = AVR32_USART_CR_RXEN_MASK |
+              AVR32_USART_CR_TXEN_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_spi_master(volatile avr32_usart_t *usart, const usart_spi_options_t *opt, long pba_hz)
+{
+  // Reset the USART and shutdown TX and RX.
+  usart_reset(usart);
+
+  // Check input values.
+  if (!opt || // Null pointer.
+      opt->charlength < 5 || opt->charlength > 9 ||
+      opt->spimode > 3 ||
+      opt->channelmode > 3 ||
+      usart_set_spi_master_baudrate(usart, opt->baudrate, pba_hz) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  if (opt->charlength == 9)
+  {
+    // Character length set to 9 bits. MODE9 dominates CHRL.
+    usart->mr |= AVR32_USART_MR_MODE9_MASK;
+  }
+  else
+  {
+    // CHRL gives the character length (- 5) when MODE9 = 0.
+    usart->mr |= (opt->charlength - 5) << AVR32_USART_MR_CHRL_OFFSET;
+  }
+
+  usart->mr |= AVR32_USART_MR_MODE_SPI_MASTER << AVR32_USART_MR_MODE_OFFSET | // SPI master mode.
+               ((opt->spimode & 0x1) ^ 0x1) << AVR32_USART_MR_SYNC_OFFSET |   // SPI clock phase.
+               opt->channelmode << AVR32_USART_MR_CHMODE_OFFSET |             // Channel mode.
+               (opt->spimode >> 1) << AVR32_USART_MR_MSBF_OFFSET |            // SPI clock polarity.
+               AVR32_USART_MR_CLKO_MASK;                                      // Drive SCK pin.
+
+  // Setup complete; enable communication.
+  // Enable input and output.
+  usart->cr = AVR32_USART_CR_RXEN_MASK |
+              AVR32_USART_CR_TXEN_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_init_spi_slave(volatile avr32_usart_t *usart, const usart_spi_options_t *opt, long pba_hz)
+{
+  // Reset the USART and shutdown TX and RX.
+  usart_reset(usart);
+
+  // Check input values.
+  if (!opt || // Null pointer.
+      opt->charlength < 5 || opt->charlength > 9 ||
+      opt->spimode > 3 ||
+      opt->channelmode > 3 ||
+      usart_set_spi_slave_baudrate(usart) == USART_INVALID_INPUT)
+    return USART_INVALID_INPUT;
+
+  if (opt->charlength == 9)
+  {
+    // Character length set to 9 bits. MODE9 dominates CHRL.
+    usart->mr |= AVR32_USART_MR_MODE9_MASK;
+  }
+  else
+  {
+    // CHRL gives the character length (- 5) when MODE9 = 0.
+    usart->mr |= (opt->charlength - 5) << AVR32_USART_MR_CHRL_OFFSET;
+  }
+
+  usart->mr |= AVR32_USART_MR_MODE_SPI_SLAVE << AVR32_USART_MR_MODE_OFFSET |  // SPI slave mode.
+               ((opt->spimode & 0x1) ^ 0x1) << AVR32_USART_MR_SYNC_OFFSET |   // SPI clock phase.
+               opt->channelmode << AVR32_USART_MR_CHMODE_OFFSET |             // Channel mode.
+               (opt->spimode >> 1) << AVR32_USART_MR_MSBF_OFFSET;             // SPI clock polarity.
+
+  // Setup complete; enable communication.
+  // Enable input and output.
+  usart->cr = AVR32_USART_CR_RXEN_MASK |
+              AVR32_USART_CR_TXEN_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+#endif  // USART rev. >= 4.0.0
+
+
+//! @}
+
+
+//------------------------------------------------------------------------------
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+
+/*! \name SPI Control Functions
+ */
+//! @{
+
+
+int usart_spi_selectChip(volatile avr32_usart_t *usart)
+{
+  // Force the SPI chip select.
+  usart->cr = AVR32_USART_CR_RTSEN_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+int usart_spi_unselectChip(volatile avr32_usart_t *usart)
+{
+  int timeout = USART_DEFAULT_TIMEOUT;
+
+  do
+  {
+    if (!timeout--) return USART_FAILURE;
+  } while (!usart_tx_empty(usart));
+
+  // Release the SPI chip select.
+  usart->cr = AVR32_USART_CR_RTSDIS_MASK;
+
+  return USART_SUCCESS;
+}
+
+
+//! @}
+
+
+#endif  // USART rev. >= 4.0.0
+
+
+//------------------------------------------------------------------------------
+/*! \name Transmit/Receive Functions
+ */
+//! @{
+
+
+int usart_send_address(volatile avr32_usart_t *usart, int address)
+{
+  // Check if USART is in multidrop / RS485 mode.
+  if (!usart_mode_is_multidrop(usart)) return USART_MODE_FAULT;
+
+  // Prepare to send an address.
+  usart->cr = AVR32_USART_CR_SENDA_MASK;
+
+  // Write the address to TX.
+  usart_bw_write_char(usart, address);
+
+  return USART_SUCCESS;
+}
+
+
+int usart_write_char(volatile avr32_usart_t *usart, int c)
+{
+  if (usart_tx_ready(usart))
+  {
+    usart->thr = (c << AVR32_USART_THR_TXCHR_OFFSET) & AVR32_USART_THR_TXCHR_MASK;
+    return USART_SUCCESS;
+  }
+  else
+    return USART_TX_BUSY;
+}
+
+
+int usart_putchar(volatile avr32_usart_t *usart, int c)
+{
+  int timeout = USART_DEFAULT_TIMEOUT;
+
+  if (c == '\n')
+  {
+    do
+    {
+      if (!timeout--) return USART_FAILURE;
+    } while (usart_write_char(usart, '\r') != USART_SUCCESS);
+
+    timeout = USART_DEFAULT_TIMEOUT;
+  }
+
+  do
+  {
+    if (!timeout--) return USART_FAILURE;
+  } while (usart_write_char(usart, c) != USART_SUCCESS);
+
+  return USART_SUCCESS;
+}
+
+
+int usart_read_char(volatile avr32_usart_t *usart, int *c)
+{
+  // Check for errors: frame, parity and overrun. In RS485 mode, a parity error
+  // would mean that an address char has been received.
+  if (usart->csr & (AVR32_USART_CSR_OVRE_MASK |
+                    AVR32_USART_CSR_FRAME_MASK |
+                    AVR32_USART_CSR_PARE_MASK))
+    return USART_RX_ERROR;
+
+  // No error; if we really did receive a char, read it and return SUCCESS.
+  if (usart_test_hit(usart))
+  {
+    *c = (usart->rhr & AVR32_USART_RHR_RXCHR_MASK) >> AVR32_USART_RHR_RXCHR_OFFSET;
+    return USART_SUCCESS;
+  }
+  else
+    return USART_RX_EMPTY;
+}
+
+
+int usart_getchar(volatile avr32_usart_t *usart)
+{
+  int c, ret;
+
+  while ((ret = usart_read_char(usart, &c)) == USART_RX_EMPTY);
+
+  if (ret == USART_RX_ERROR)
+    return USART_FAILURE;
+
+  return c;
+}
+
+
+void usart_write_line(volatile avr32_usart_t *usart, const char *string)
+{
+  while (*string != '\0')
+    usart_putchar(usart, *string++);
+}
+
+
+int usart_get_echo_line(volatile avr32_usart_t *usart)
+{
+  int rx_char;
+  int retval = USART_SUCCESS;
+
+  while (1)
+  {
+    rx_char = usart_getchar(usart);
+    if (rx_char == USART_FAILURE)
+    {
+      usart_write_line(usart, "Error!!!\n");
+      retval = USART_FAILURE;
+      break;
+    }
+    if (rx_char == '\x03')
+    {
+      retval = USART_FAILURE;
+      break;
+    }
+    usart_putchar(usart, rx_char);
+    if (rx_char == '\r')
+    {
+      usart_putchar(usart, '\n');
+      break;
+    }
+  }
+
+  return retval;
+}
+
+
+//! @}
diff --git a/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/USART/usart.h b/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/USART/usart.h
new file mode 100644
index 0000000..bc1c100
--- /dev/null
+++ b/firmwares/wifishield/wifiHD/src/SOFTWARE_FRAMEWORK/DRIVERS/USART/usart.h
@@ -0,0 +1,889 @@
+/* This header file is part of the ATMEL AVR-UC3-SoftwareFramework-1.7.0 Release */
+
+/*This file is prepared for Doxygen automatic documentation generation.*/
+/*! \file *********************************************************************
+ *
+ * \brief USART driver for AVR32 UC3.
+ *
+ * This file contains basic functions for the AVR32 USART, with support for all
+ * modes, settings and clock speeds.
+ *
+ * - Compiler:           IAR EWAVR32 and GNU GCC for AVR32
+ * - Supported devices:  All AVR32 devices with a USART module can be used.
+ * - AppNote:
+ *
+ * \author               Atmel Corporation: http://www.atmel.com \n
+ *                       Support and FAQ: http://support.atmel.no/
+ *
+ ******************************************************************************/
+
+/* Copyright (c) 2009 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:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice, this
+ * list of conditions and the following disclaimer.
+ *
+ * 2. 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.
+ *
+ * 3. The name of Atmel may not be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * 4. This software may only be redistributed and used in connection with an Atmel
+ * AVR product.
+ *
+ * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
+ * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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
+ *
+ */
+
+#ifndef _USART_H_
+#define _USART_H_
+
+#include <avr32/io.h>
+#include "compiler.h"
+
+
+/*! \name Return Values
+ */
+//! @{
+#define USART_SUCCESS                 0 //!< Successful completion.
+#define USART_FAILURE                -1 //!< Failure because of some unspecified reason.
+#define USART_INVALID_INPUT           1 //!< Input value out of range.
+#define USART_INVALID_ARGUMENT       -1 //!< Argument value out of range.
+#define USART_TX_BUSY                 2 //!< Transmitter was busy.
+#define USART_RX_EMPTY                3 //!< Nothing was received.
+#define USART_RX_ERROR                4 //!< Transmission error occurred.
+#define USART_MODE_FAULT              5 //!< USART not in the appropriate mode.
+//! @}
+
+//! Default time-out value (number of attempts).
+#define USART_DEFAULT_TIMEOUT         10000
+
+/*! \name Parity Settings
+ */
+//! @{
+#define USART_EVEN_PARITY             AVR32_USART_MR_PAR_EVEN   //!< Use even parity on character transmission.
+#define USART_ODD_PARITY              AVR32_USART_MR_PAR_ODD    //!< Use odd parity on character transmission.
+#define USART_SPACE_PARITY            AVR32_USART_MR_PAR_SPACE  //!< Use a space as parity bit.
+#define USART_MARK_PARITY             AVR32_USART_MR_PAR_MARK   //!< Use a mark as parity bit.
+#define USART_NO_PARITY               AVR32_USART_MR_PAR_NONE   //!< Don't use a parity bit.
+#define USART_MULTIDROP_PARITY        AVR32_USART_MR_PAR_MULTI  //!< Parity bit is used to flag address characters.
+//! @}
+
+/*! \name Stop Bits Settings
+ */
+//! @{
+#define USART_1_STOPBIT               AVR32_USART_MR_NBSTOP_1   //!< Use 1 stop bit.
+#define USART_1_5_STOPBITS            AVR32_USART_MR_NBSTOP_1_5 //!< Use 1.5 stop bits.
+#define USART_2_STOPBITS              AVR32_USART_MR_NBSTOP_2   //!< Use 2 stop bits (for more, just give the number of bits).
+//! @}
+
+/*! \name Channel Modes
+ */
+//! @{
+#define USART_NORMAL_CHMODE           AVR32_USART_MR_CHMODE_NORMAL      //!< Normal communication.
+#define USART_AUTO_ECHO               AVR32_USART_MR_CHMODE_ECHO        //!< Echo data.
+#define USART_LOCAL_LOOPBACK          AVR32_USART_MR_CHMODE_LOCAL_LOOP  //!< Local loopback.
+#define USART_REMOTE_LOOPBACK         AVR32_USART_MR_CHMODE_REMOTE_LOOP //!< Remote loopback.
+//! @}
+
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+/*! \name LIN Node Actions
+ */
+//! @{
+#define USART_LIN_PUBLISH_ACTION      AVR32_USART_LINMR_NACT_PUBLISH    //!< The USART transmits the response.
+#define USART_LIN_SUBSCRIBE_ACTION    AVR32_USART_LINMR_NACT_SUBSCRIBE  //!< The USART receives the response.
+#define USART_LIN_IGNORE_ACTION       AVR32_USART_LINMR_NACT_IGNORE     //!< The USART does not transmit and does not receive the reponse.
+//! @}
+
+/*! \name LIN Checksum Types
+ */
+//! @{
+#define USART_LIN_ENHANCED_CHECKSUM   0 //!< LIN 2.0 "enhanced" checksum.
+#define USART_LIN_CLASSIC_CHECKSUM    1 //!< LIN 1.3 "classic" checksum.
+//! @}
+
+#endif  // USART rev. >= 4.0.0
+
+
+//! Input parameters when initializing RS232 and similar modes.
+typedef struct
+{
+  //! Set baud rate of the USART (unused in slave modes).
+  unsigned long baudrate;
+
+  //! Number of bits to transmit as a character (5 to 9).
+  unsigned char charlength;
+
+  //! How to calculate the parity bit: \ref USART_EVEN_PARITY, \ref USART_ODD_PARITY,
+  //! \ref USART_SPACE_PARITY, \ref USART_MARK_PARITY, \ref USART_NO_PARITY or
+  //! \ref USART_MULTIDROP_PARITY.
+  unsigned char paritytype;
+
+  //! Number of stop bits between two characters: \ref USART_1_STOPBIT,
+  //! \ref USART_1_5_STOPBITS, \ref USART_2_STOPBITS or any number from 3 to 257
+  //! which will result in a time guard period of that length between characters.
+  //! \note \ref USART_1_5_STOPBITS is supported in asynchronous modes only.
+  unsigned short stopbits;
+
+  //! Run the channel in testmode: \ref USART_NORMAL_CHMODE, \ref USART_AUTO_ECHO,
+  //! \ref USART_LOCAL_LOOPBACK or \ref USART_REMOTE_LOOPBACK.
+  unsigned char channelmode;
+} usart_options_t;
+
+//! Input parameters when initializing ISO7816 mode.
+typedef struct
+{
+  //! Set the frequency of the ISO7816 clock.
+  unsigned long iso7816_hz;
+
+  //! The number of ISO7816 clock ticks in every bit period (1 to 2047, 0 = disable clock).
+  //! Bit rate = \ref iso7816_hz / \ref fidi_ratio.
+  unsigned short fidi_ratio;
+
+  //! How to calculate the parity bit: \ref USART_EVEN_PARITY for normal mode or
+  //! \ref USART_ODD_PARITY for inverse mode.
+  unsigned char paritytype;
+
+  //! Inhibit Non Acknowledge:\n
+  //!   - 0: the NACK is generated;\n
+  //!   - 1: the NACK is not generated.
+  //!
+  //! \note This bit will be used only in ISO7816 mode, protocol T = 0 receiver.
+  int inhibit_nack;
+
+  //! Disable successive NACKs.
+  //! Successive parity errors are counted up to the value in the \ref max_iterations field.
+  //! These parity errors generate a NACK on the ISO line. As soon as this value is reached,
+  //! no addititional NACK is sent on the ISO line. The ITERATION flag is asserted.
+  int dis_suc_nack;
+
+  //! Max number of repetitions (0 to 7).
+  unsigned char max_iterations;
+
+  //! Bit order in transmitted characters:\n
+  //!   - 0: LSB first;\n
+  //!   - 1: MSB first.
+  int bit_order;
+} usart_iso7816_options_t;
+
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+//! Input parameters when initializing SPI mode.
+typedef struct
+{
+  //! Set the frequency of the SPI clock (unused in slave mode).
+  unsigned long baudrate;
+
+  //! Number of bits to transmit as a character (5 to 9).
+  unsigned char charlength;
+
+  //! Which SPI mode to use.
+  unsigned char spimode;
+
+  //! Run the channel in testmode: \ref USART_NORMAL_CHMODE, \ref USART_AUTO_ECHO,
+  //! \ref USART_LOCAL_LOOPBACK or \ref USART_REMOTE_LOOPBACK.
+  unsigned char channelmode;
+} usart_spi_options_t;
+
+#endif  // USART rev. >= 4.0.0
+
+
+//------------------------------------------------------------------------------
+/*! \name Initialization Functions
+ */
+//! @{
+
+/*! \brief Resets the USART and disables TX and RX.
+ *
+ * \param usart   Base address of the USART instance.
+ */
+extern void usart_reset(volatile avr32_usart_t *usart);
+
+/*! \brief Sets up the USART to use the standard RS232 protocol.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ */
+extern int usart_init_rs232(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);
+
+/*! \brief Sets up the USART to use the standard RS232 protocol in TX-only mode.
+ *
+ * Compared to \ref usart_init_rs232, this function allows very high baud rates
+ * (up to \a pba_hz instead of \a pba_hz / \c 8) at the expense of full duplex.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ *
+ * \note The \c 1.5 stop bit is not supported in this mode.
+ */
+extern int usart_init_rs232_tx_only(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);
+
+/*! \brief Sets up the USART to use hardware handshaking.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ *
+ * \note \ref usart_init_rs232 does not need to be invoked before this function.
+ */
+extern int usart_init_hw_handshaking(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);
+
+/*! \brief Sets up the USART to use the modem protocol, activating dedicated inputs/outputs.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ */
+extern int usart_init_modem(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);
+
+/*! \brief Sets up the USART to use a synchronous RS232-like protocol in master mode.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ */
+extern int usart_init_sync_master(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);
+
+/*! \brief Sets up the USART to use a synchronous RS232-like protocol in slave mode.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ */
+extern int usart_init_sync_slave(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);
+
+/*! \brief Sets up the USART to use the RS485 protocol.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up RS232 communication (see \ref usart_options_t).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ */
+extern int usart_init_rs485(volatile avr32_usart_t *usart, const usart_options_t *opt, long pba_hz);
+
+/*! \brief Sets up the USART to use the IrDA protocol.
+ *
+ * \param usart         Base address of the USART instance.
+ * \param opt           Options needed to set up RS232 communication (see \ref usart_options_t).
+ * \param pba_hz        USART module input clock frequency (PBA clock, Hz).
+ * \param irda_filter   Counter used to distinguish received ones from zeros.
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ */
+extern int usart_init_IrDA(volatile avr32_usart_t *usart, const usart_options_t *opt,
+                           long pba_hz, unsigned char irda_filter);
+
+/*! \brief Sets up the USART to use the ISO7816 T=0 or T=1 smartcard protocols.
+ *
+ * The receiver is enabled by default. \ref usart_iso7816_enable_receiver and
+ * \ref usart_iso7816_enable_transmitter can be called to change the half-duplex
+ * communication direction.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up ISO7816 communication (see \ref usart_iso7816_options_t).
+ * \param t       ISO7816 mode to use (T=0 or T=1).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ */
+extern int usart_init_iso7816(volatile avr32_usart_t *usart, const usart_iso7816_options_t *opt, int t, long pba_hz);
+
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+/*! \brief Sets up the USART to use the LIN master mode.
+ *
+ * \param usart     Base address of the USART instance.
+ * \param baudrate  Baud rate.
+ * \param pba_hz    USART module input clock frequency (PBA clock, Hz).
+ *
+ */
+extern int usart_init_lin_master(volatile avr32_usart_t *usart, unsigned long baudrate, long pba_hz);
+
+/*! \brief Sets up the USART to use the LIN slave mode.
+ *
+ * \param usart     Base address of the USART instance.
+ * \param baudrate  Baud rate.
+ * \param pba_hz    USART module input clock frequency (PBA clock, Hz).
+ *
+ */
+extern int usart_init_lin_slave(volatile avr32_usart_t *usart, unsigned long baudrate, long pba_hz);
+
+/*! \brief Sets up the USART to use the SPI master mode.
+ *
+ * \ref usart_spi_selectChip and \ref usart_spi_unselectChip can be called to
+ * select or unselect the SPI slave chip.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up SPI mode (see \ref usart_spi_options_t).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ */
+extern int usart_init_spi_master(volatile avr32_usart_t *usart, const usart_spi_options_t *opt, long pba_hz);
+
+/*! \brief Sets up the USART to use the SPI slave mode.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param opt     Options needed to set up SPI mode (see \ref usart_spi_options_t).
+ * \param pba_hz  USART module input clock frequency (PBA clock, Hz).
+ *
+ * \retval USART_SUCCESS        Mode successfully initialized.
+ * \retval USART_INVALID_INPUT  One or more of the arguments is out of valid range.
+ */
+extern int usart_init_spi_slave(volatile avr32_usart_t *usart, const usart_spi_options_t *opt, long pba_hz);
+
+#endif  // USART rev. >= 4.0.0
+
+//! @}
+
+
+//------------------------------------------------------------------------------
+/*! \name Read and Reset Error Status Bits
+ */
+//! @{
+
+/*! \brief Resets the error status.
+ *
+ * This function resets the status bits indicating that a parity error,
+ * framing error or overrun has occurred. The RXBRK bit, indicating
+ * a start/end of break condition on the RX line, is also reset.
+ *
+ * \param usart   Base address of the USART instance.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_reset_status(volatile avr32_usart_t *usart)
+{
+  usart->cr = AVR32_USART_CR_RSTSTA_MASK;
+}
+
+/*! \brief Checks if a parity error has occurred since last status reset.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return \c 1 if a parity error has been detected, otherwise \c 0.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ int usart_parity_error(volatile avr32_usart_t *usart)
+{
+  return (usart->csr & AVR32_USART_CSR_PARE_MASK) != 0;
+}
+
+/*! \brief Checks if a framing error has occurred since last status reset.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return \c 1 if a framing error has been detected, otherwise \c 0.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ int usart_framing_error(volatile avr32_usart_t *usart)
+{
+  return (usart->csr & AVR32_USART_CSR_FRAME_MASK) != 0;
+}
+
+/*! \brief Checks if an overrun error has occurred since last status reset.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return \c 1 if a overrun error has been detected, otherwise \c 0.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ int usart_overrun_error(volatile avr32_usart_t *usart)
+{
+  return (usart->csr & AVR32_USART_CSR_OVRE_MASK) != 0;
+}
+
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+/*! \brief Get LIN Error Status
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \retval The binary value of the error field.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ int usart_lin_get_error(volatile avr32_usart_t *usart)
+{
+  return (usart->csr & (AVR32_USART_CSR_LINSNRE_MASK |
+                        AVR32_USART_CSR_LINCE_MASK |
+                        AVR32_USART_CSR_LINIPE_MASK |
+                        AVR32_USART_CSR_LINISFE_MASK |
+                        AVR32_USART_CSR_LINBE_MASK)) >> AVR32_USART_CSR_LINBE_OFFSET;
+}
+
+#endif  // USART rev. >= 4.0.0
+
+//! @}
+
+
+//------------------------------------------------------------------------------
+/*! \name ISO7816 Control Functions
+ */
+//! @{
+
+/*! \brief Enables the ISO7816 receiver.
+ *
+ * The ISO7816 transmitter is disabled.
+ *
+ * \param usart   Base address of the USART instance.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_iso7816_enable_receiver(volatile avr32_usart_t *usart)
+{
+  usart->cr = AVR32_USART_CR_TXDIS_MASK | AVR32_USART_CR_RXEN_MASK;
+}
+
+/*! \brief Enables the ISO7816 transmitter.
+ *
+ * The ISO7816 receiver is disabled.
+ *
+ * \param usart   Base address of the USART instance.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_iso7816_enable_transmitter(volatile avr32_usart_t *usart)
+{
+  usart->cr = AVR32_USART_CR_RXDIS_MASK | AVR32_USART_CR_TXEN_MASK;
+}
+
+//! @}
+
+
+//------------------------------------------------------------------------------
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+/*! \name LIN Control Functions
+ */
+//! @{
+
+/*! \brief Sets the node action.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param action  The node action: \ref USART_LIN_PUBLISH_ACTION,
+ *                \ref USART_LIN_SUBSCRIBE_ACTION or
+ *                \ref USART_LIN_IGNORE_ACTION.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_lin_set_node_action(volatile avr32_usart_t *usart, unsigned char action)
+{
+  usart->linmr = (usart->linmr & ~AVR32_USART_LINMR_NACT_MASK) |
+                 action << AVR32_USART_LINMR_NACT_OFFSET;
+}
+
+/*! \brief Enables or disables the Identifier parity.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param parity  Whether to enable the Identifier parity: \c TRUE or \c FALSE.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_lin_enable_parity(volatile avr32_usart_t *usart, unsigned char parity)
+{
+  usart->linmr = (usart->linmr & ~AVR32_USART_LINMR_PARDIS_MASK) |
+                 !parity << AVR32_USART_LINMR_PARDIS_OFFSET;
+}
+
+/*! \brief Enables or disables the checksum.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param parity  Whether to enable the checksum: \c TRUE or \c FALSE.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_lin_enable_checksum(volatile avr32_usart_t *usart, unsigned char checksum)
+{
+  usart->linmr = (usart->linmr & ~AVR32_USART_LINMR_CHKDIS_MASK) |
+                 !checksum << AVR32_USART_LINMR_CHKDIS_OFFSET;
+}
+
+/*! \brief Sets the checksum type.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param chktyp  The checksum type: \ref USART_LIN_ENHANCED_CHEKSUM or
+ *                \ref USART_LIN_CLASSIC_CHECKSUM.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_lin_set_checksum(volatile avr32_usart_t *usart, unsigned char chktyp)
+{
+  usart->linmr = (usart->linmr & ~AVR32_USART_LINMR_CHKTYP_MASK) |
+                 chktyp << AVR32_USART_LINMR_CHKTYP_OFFSET;
+}
+
+/*! \brief Gets the response data length.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return The response data length.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ unsigned char usart_lin_get_data_length(volatile avr32_usart_t *usart)
+{
+  if (usart->linmr & AVR32_USART_LINMR_DLM_MASK)
+  {
+    unsigned char data_length = 1 << ((usart->linir >> (AVR32_USART_LINIR_IDCHR_OFFSET + 4)) & 0x03);
+    if (data_length == 1)
+      data_length = 2;
+    return data_length;
+  }
+  else
+    return ((usart->linmr & AVR32_USART_LINMR_DLC_MASK) >> AVR32_USART_LINMR_DLC_OFFSET) + 1;
+}
+
+/*! \brief Sets the response data length for LIN 1.x.
+ *
+ * \param usart   Base address of the USART instance.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_lin_set_data_length_lin1x(volatile avr32_usart_t *usart)
+{
+  usart->linmr |= AVR32_USART_LINMR_DLM_MASK;
+}
+
+/*! \brief Sets the response data length for LIN 2.x.
+ *
+ * \param usart         Base address of the USART instance.
+ * \param data_length   The response data length.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_lin_set_data_length_lin2x(volatile avr32_usart_t *usart, unsigned char data_length)
+{
+  usart->linmr = (usart->linmr & ~(AVR32_USART_LINMR_DLC_MASK |
+                                   AVR32_USART_LINMR_DLM_MASK)) |
+                 (data_length - 1) << AVR32_USART_LINMR_DLC_OFFSET;
+}
+
+/*! \brief Enables or disables the frame slot mode.
+ *
+ * \param usart       Base address of the USART instance.
+ * \param frameslot   Whether to enable the frame slot mode: \c TRUE or
+ *                    \c FALSE.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_lin_enable_frameslot(volatile avr32_usart_t *usart, unsigned char frameslot)
+{
+  usart->linmr = (usart->linmr & ~AVR32_USART_LINMR_FSDIS_MASK) |
+                 !frameslot << AVR32_USART_LINMR_FSDIS_OFFSET;
+}
+
+/*! \brief Gets the Identifier character.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return The Identifier character.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ unsigned char usart_lin_get_id_char(volatile avr32_usart_t *usart)
+{
+  return (usart->linir & AVR32_USART_LINIR_IDCHR_MASK) >> AVR32_USART_LINIR_IDCHR_OFFSET;
+}
+
+/*! \brief Sets the Identifier character.
+ *
+ * \param usart     Base address of the USART instance.
+ * \param id_char   The Identifier character.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_lin_set_id_char(volatile avr32_usart_t *usart, unsigned char id_char)
+{
+  usart->linir = (usart->linir & ~AVR32_USART_LINIR_IDCHR_MASK) |
+                 id_char << AVR32_USART_LINIR_IDCHR_OFFSET;
+}
+
+//! @}
+
+#endif  // USART rev. >= 4.0.0
+
+
+//------------------------------------------------------------------------------
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+/*! \name SPI Control Functions
+ */
+//! @{
+
+/*! \brief Selects SPI slave chip.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \retval USART_SUCCESS        Success.
+ */
+extern int usart_spi_selectChip(volatile avr32_usart_t *usart);
+
+/*! \brief Unselects SPI slave chip.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \retval USART_SUCCESS        Success.
+ * \retval USART_FAILURE        Time-out.
+ */
+extern int usart_spi_unselectChip(volatile avr32_usart_t *usart);
+
+//! @}
+
+#endif  // USART rev. >= 4.0.0
+
+
+//------------------------------------------------------------------------------
+/*! \name Transmit/Receive Functions
+ */
+//! @{
+
+/*! \brief Addresses a receiver.
+ *
+ * While in RS485 mode, receivers only accept data addressed to them.
+ * A packet/char with the address tag set has to precede any data.
+ * This function is used to address a receiver. This receiver should read
+ * all the following data, until an address packet addresses another receiver.
+ *
+ * \param usart     Base address of the USART instance.
+ * \param address   Address of the target device.
+ *
+ * \retval USART_SUCCESS    Address successfully sent (if current mode is RS485).
+ * \retval USART_MODE_FAULT Wrong operating mode.
+ */
+extern int usart_send_address(volatile avr32_usart_t *usart, int address);
+
+/*! \brief Tests if the USART is ready to transmit a character.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return \c 1 if the USART Transmit Holding Register is free, otherwise \c 0.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ int usart_tx_ready(volatile avr32_usart_t *usart)
+{
+  return (usart->csr & AVR32_USART_CSR_TXRDY_MASK) != 0;
+}
+
+/*! \brief Writes the given character to the TX buffer if the transmitter is ready.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param c       The character (up to 9 bits) to transmit.
+ *
+ * \retval USART_SUCCESS  The transmitter was ready.
+ * \retval USART_TX_BUSY  The transmitter was busy.
+ */
+extern int usart_write_char(volatile avr32_usart_t *usart, int c);
+
+/*! \brief An active wait writing a character to the USART.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param c       The character (up to 9 bits) to transmit.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_bw_write_char(volatile avr32_usart_t *usart, int c)
+{
+  while (usart_write_char(usart, c) != USART_SUCCESS);
+}
+
+/*! \brief Sends a character with the USART.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param c       Character to write.
+ *
+ * \retval USART_SUCCESS  The character was written.
+ * \retval USART_FAILURE  The function timed out before the USART transmitter became ready to send.
+ */
+extern int usart_putchar(volatile avr32_usart_t *usart, int c);
+
+/*! \brief Tests if all requested USART transmissions are over.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return \c 1 if the USART Transmit Shift Register and the USART Transmit
+ *         Holding Register are free, otherwise \c 0.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ int usart_tx_empty(volatile avr32_usart_t *usart)
+{
+  return (usart->csr & AVR32_USART_CSR_TXEMPTY_MASK) != 0;
+}
+
+/*! \brief Tests if the USART contains a received character.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return \c 1 if the USART Receive Holding Register is full, otherwise \c 0.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ int usart_test_hit(volatile avr32_usart_t *usart)
+{
+  return (usart->csr & AVR32_USART_CSR_RXRDY_MASK) != 0;
+}
+
+/*! \brief Checks the RX buffer for a received character, and stores it at the
+ *         given memory location.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param c       Pointer to the where the read character should be stored
+ *                (must be at least short in order to accept 9-bit characters).
+ *
+ * \retval USART_SUCCESS  The character was read successfully.
+ * \retval USART_RX_EMPTY The RX buffer was empty.
+ * \retval USART_RX_ERROR An error was deteceted.
+ */
+extern int usart_read_char(volatile avr32_usart_t *usart, int *c);
+
+/*! \brief Waits until a character is received, and returns it.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return The received character, or \ref USART_FAILURE upon error.
+ */
+extern int usart_getchar(volatile avr32_usart_t *usart);
+
+/*! \brief Writes one character string to the USART.
+ *
+ * \param usart   Base address of the USART instance.
+ * \param string  String to be written.
+ */
+extern void usart_write_line(volatile avr32_usart_t *usart, const char *string);
+
+/*! \brief Gets and echoes characters until end of line.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \retval USART_SUCCESS  Success.
+ * \retval USART_FAILURE  Low-level error detected or ETX character received.
+ */
+extern int usart_get_echo_line(volatile avr32_usart_t *usart);
+
+#if defined(AVR32_USART_400_H_INCLUDED) || \
+    defined(AVR32_USART_410_H_INCLUDED) || \
+    defined(AVR32_USART_420_H_INCLUDED) || \
+    defined(AVR32_USART_440_H_INCLUDED) || \
+    defined(AVR32_USART_602_H_INCLUDED)
+
+/*! \brief Abort LIN transmission.
+ *
+ * \param usart   Base address of the USART instance.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ void usart_lin_abort(volatile avr32_usart_t *usart)
+{
+  usart->cr = AVR32_USART_LINABT_MASK;
+}
+
+/*! \brief Tests if a LIN transfer has been completed.
+ *
+ * \param usart   Base address of the USART instance.
+ *
+ * \return \c 1 if a LIN transfer has been completed, otherwise \c 0.
+ */
+#if (defined __GNUC__)
+__attribute__((__always_inline__))
+#endif
+extern __inline__ int usart_lin_transfer_completed(volatile avr32_usart_t *usart)
+{
+  return (usart->csr & AVR32_USART_CSR_LINTC_MASK) != 0;
+}
+
+#endif  // USART rev. >= 4.0.0
+
+//! @}
+
+
+#endif  // _USART_H_