| /** | |
| * \file | |
| * | |
| * \brief SAM D20 USART Interface Driver | |
| * | |
| * Copyright (C) 2012-2013 Atmel Corporation. All rights reserved. | |
| * | |
| * \asf_license_start | |
| * | |
| * \page License | |
| * | |
| * 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 microcontroller 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. | |
| * | |
| * \asf_license_stop | |
| * | |
| */ | |
| /** | |
| * \page asfdoc_samd20_sercom_usart_basic_use_case Quick Start Guide for SERCOM USART - Basic | |
| * | |
| * This quick start will echo back characters typed into the terminal. In this | |
| * use case the USART will be configured with the following settings: | |
| * - Asynchronous mode | |
| * - 9600 Baudrate | |
| * - 8-bits, No Parity and 1 Stop Bit | |
| * - TX and RX enabled and connected to the Xplained PRO Embedded Debugger virtual COM port | |
| * | |
| * \section asfdoc_samd20_sercom_usart_basic_use_case_setup Setup | |
| * | |
| * \subsection asfdoc_samd20_sercom_usart_basic_use_case_prereq Prerequisites | |
| * There are no special setup requirements for this use-case. | |
| * | |
| * \subsection asfdoc_samd20_usart_basic_use_case_setup_code Code | |
| * Add to the main application source file, outside of any functions: | |
| * \snippet qs_usart_basic_use.c module_inst | |
| * | |
| * Copy-paste the following setup code to your user application: | |
| * \snippet qs_usart_basic_use.c setup | |
| * | |
| * Add to user application initialization (typically the start of \c main()): | |
| * \snippet qs_usart_basic_use.c setup_init | |
| * | |
| * \subsection asfdoc_samd20_usart_basic_use_case_setup_flow Workflow | |
| * -# Create a module software instance structure for the USART module to store | |
| * the USART driver state while it is in use. | |
| * \note This should never go out of scope as long as the module is in use. | |
| * In most cases, this should be global. | |
| * | |
| * \snippet qs_usart_basic_use.c module_inst | |
| * -# Configure the USART module. | |
| * -# Create a USART module configuration struct, which can be filled out to | |
| * adjust the configuration of a physical USART peripheral. | |
| * \snippet qs_usart_basic_use.c setup_config | |
| * -# Initialize the USART configuration struct with the module's default values. | |
| * \note This should always be performed before using the configuration | |
| * struct to ensure that all values are initialized to known default | |
| * settings. | |
| * | |
| * \snippet qs_usart_basic_use.c setup_config_defaults | |
| * -# Alter the USART settings to configure the physical pinout, baud rate and | |
| * other relevant parameters. | |
| * \snippet qs_usart_basic_use.c setup_change_config | |
| * -# Configure the USART module with the desired settings, retrying while the | |
| * driver is busy until the configuration is stressfully set. | |
| * \snippet qs_usart_basic_use.c setup_set_config | |
| * -# Enable the USART module. | |
| * \snippet qs_usart_basic_use.c setup_enable | |
| * | |
| * | |
| * \section asfdoc_samd20_usart_basic_use_case_main Use Case | |
| * | |
| * \subsection asfdoc_samd20_usart_basic_use_case_main_code Code | |
| * Copy-paste the following code to your user application: | |
| * \snippet qs_usart_basic_use.c main | |
| * | |
| * \subsection asfdoc_samd20_usart_basic_use_case_main_flow Workflow | |
| * -# Send a string to the USART to show the demo is running, blocking until | |
| * all characters have been sent. | |
| * \snippet qs_usart_basic_use.c main_send_string | |
| * -# Enter an infinite loop to continuously echo received values on the USART. | |
| * \snippet qs_usart_basic_use.c main_loop | |
| * -# Perform a blocking read of the USART, storing the received character into | |
| * the previously declared temporary variable. | |
| * \snippet qs_usart_basic_use.c main_read | |
| * -# Echo the received variable back to the USART via a blocking write. | |
| * \snippet qs_usart_basic_use.c main_write | |
| */ |