| /** | |
| * \file | |
| * | |
| * \brief SAM D20 External Interrupt Driver Quick Start | |
| * | |
| * 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 | |
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| * \asf_license_stop | |
| * | |
| */ | |
| /** | |
| * \page asfdoc_samd20_system_interrupt_critsec_use_case Quick Start Guide for SYSTEM INTERRUPT - Critical Section Use Case | |
| * | |
| * In this case we perform a critical piece of code, disabling all interrupts | |
| * while a global shared flag is read. During the critical section, no interrupts | |
| * may occur. | |
| * | |
| * \section asfdoc_samd20_system_interrupt_critsec_use_case_setup Setup | |
| * | |
| * \subsection asfdoc_samd20_system_interrupt_critsec_use_case_setup_prereq Prerequisites | |
| * There are no special setup requirements for this use-case. | |
| * | |
| * \section asfdoc_samd20_system_interrupt_critsec_use_case_use_main Use Case | |
| * | |
| * \subsection asfdoc_samd20_system_interrupt_critsec_use_case_code Code | |
| * Copy-paste the following code to your user application: | |
| * \snippet qs_system_interrupt.c main_1 | |
| * | |
| * \subsection asfdoc_samd20_system_interrupt_critsec_use_case_flow Workflow | |
| * -# Enter a critical section to disable global interrupts. | |
| * \note Critical sections <i>may</i> be nested if desired; if nested, global | |
| * interrupts will only be re-enabled once the outer-most critical | |
| * section has completed. | |
| * | |
| * \snippet qs_system_interrupt.c critical_section_start | |
| * | |
| * -# Check a global shared flag and perform a response. This code may be any | |
| * critical code that requires exclusive access to all resources without the | |
| * possibility of interruption. | |
| * \snippet qs_system_interrupt.c do_critical_code | |
| * | |
| * -# Exit the critical section to re-enable global interrupts. | |
| * \snippet qs_system_interrupt.c critical_section_end | |
| */ | |
| /** | |
| * \page asfdoc_samd20_system_interrupt_enablemodint_use_case Quick Start Guide for SYSTEM INTERRUPT - Enable Module Interrupt Use Case | |
| * | |
| * In this case we enable interrupt handling for a specific module, as well as | |
| * enable interrupts globally for the device. | |
| * | |
| * \section asfdoc_samd20_system_interrupt_enablemodint_use_case_setup Setup | |
| * | |
| * \subsection asfdoc_samd20_system_interrupt_enablemodint_use_case_setup_prereq Prerequisites | |
| * There are no special setup requirements for this use-case. | |
| * | |
| * \section asfdoc_samd20_system_interrupt_enablemodint_use_case_use_main Use Case | |
| * | |
| * \subsection asfdoc_samd20_system_interrupt_enablemodint_use_case_code Code | |
| * Copy-paste the following code to your user application: | |
| * \snippet qs_system_interrupt.c main_2 | |
| * | |
| * \subsection asfdoc_samd20_system_interrupt_enablemodint_use_case_flow Workflow | |
| * -# Enable interrupt handling for the device's RTC peripheral. | |
| * \snippet qs_system_interrupt.c module_int_enable | |
| * | |
| * -# Enable global interrupts, so that any enabled and active interrupt sources | |
| * can trigger their respective handler functions. | |
| * \snippet qs_system_interrupt.c global_int_enable | |
| */ |