/**
 * \file
 *
 * \brief SAM D20 PINMUX Driver Quick Start
 *
 * Copyright (C) 2012-2013 Atmel Corporation. All rights reserved.
 *
 * \asf_license_start
 *
 * \page License
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 *
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/**
 * \page asfdoc_samd20_system_pinmux_basic_use_case Quick Start Guide for SYSTEM PINMUX - Basic
 *
 * In this use case, the PINMUX module is configured for:
 *  \li One pin in input mode, with pull-up enabled, connected to the GPIO
 *      module
 *  \li Sampling mode of the pin changed to sample on demand
 *
 * This use case sets up the PINMUX to configure a physical I/O pin set as
 * an input with pull-up. and changes the sampling mode of the pin to reduce
 * power by only sampling the physical pin state when the user application
 * attempts to read it.
 *
 * \section asfdoc_samd20_system_pinmux_basic_use_case_setup Setup
 *
 * \subsection asfdoc_samd20_system_pinmux_basic_use_case_setup_prereq Prerequisites
 * There are no special setup requirements for this use-case.
 *
 * \section asfdoc_samd20_system_pinmux_basic_use_case_use_main Use Case
 *
 * \subsection asfdoc_samd20_system_pinmux_basic_use_case_code Code
 * Copy-paste the following code to your user application:
 * \snippet qs_pinmux_basic.c main
 *
 * \subsection asfdoc_samd20_system_pinmux_basic_use_case_flow Workflow
 * -# Create a PINMUX module pin configuration struct, which can be filled out
 *    to adjust the configuration of a single port pin.
 *  \snippet qs_pinmux_basic.c pinmux_config
 * -# Initialize the pin 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_pinmux_basic.c pinmux_config_defaults
 * -# Adjust the configuration struct to request an input pin with pullup
 *    connected to the GPIO peripheral.
 *  \snippet qs_pinmux_basic.c pinmux_update_config_values
 * -# Configure GPIO10 with the initialized pin configuration struct, to enable
 *    the input sampler on the pin.
 *  \snippet qs_pinmux_basic.c pinmux_set_config
 * -# Adjust the configuration of the pin to enable on-demand sampling mode.
 *  \snippet qs_pinmux_basic.c pinmux_change_input_sampling
 */