FreeRTOS.zip_M451_freertos

/* FreeRTOS V7.4.0 - Copyright (C) 2013 Real Time Engineers Ltd. FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. *************************************************************************** * * * FreeRTOS tutorial books are available in pdf and paperback. * * Complete, revised, and edited pdf reference manuals are also * * available. * * * * Purchasing FreeRTOS documentation will not only help you, by * * ensuring you get running as quickly as possible and with an * * in-depth knowledge of how to use FreeRTOS, it will also help * * the FreeRTOS project to continue with its mission of providing * * professional grade, cross platform, de facto standard solutions * * for microcontrollers - completely free of charge! * * * * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * * * * Thank you for using FreeRTOS, and thank you for your support! * * * *************************************************************************** This file is part of the FreeRTOS distribution. FreeRTOS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License (version 2) as published by the Free Software Foundation AND MODIFIED BY the FreeRTOS exception. >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to distribute a combined work that includes FreeRTOS without being obliged to provide the source code for proprietary components outside of the FreeRTOS kernel. FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License and the FreeRTOS license exception along with FreeRTOS; if not itcan be viewed here: http://www.freertos.org/a00114.html and also obtained by writing to Real Time Engineers Ltd., contact details for whom are available on the FreeRTOS WEB site. 1 tab == 4 spaces! *************************************************************************** * * * Having a problem? Start by reading the FAQ "My application does * * not run, what could be wrong?" * * * * http://www.FreeRTOS.org/FAQHelp.html * * * *************************************************************************** http://www.FreeRTOS.org - Documentation, books, training, latest versions, license and Real Time Engineers Ltd. contact details. http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, including FreeRTOS+Trace - an indispensable productivity tool, and our new fully thread aware and reentrant UDP/IP stack. http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell the code with commercial support, indemnification and middleware, under the OpenRTOS brand. http://www.SafeRTOS.com - High Integrity Systems also provide a safety engineered and independently SIL3 certified version for use in safety and mission critical applications that require provable dependability. */ /****************************************************************************** * >>>>>> NOTE 1: <<<<<< * * main() can be configured to create either a very simple LED flasher demo, or * a more comprehensive test/demo application. * * To create a very simple LED flasher example, set the * mainCREATE_SIMPLE_LED_FLASHER_DEMO_ONLY constant (defined below) to 1. When * this is done, only the standard demo flash tasks are created. The standard * demo flash example creates three tasks, each of which toggle an LED at a * fixed but different frequency. * * To create a more comprehensive test and demo application, set * mainCREATE_SIMPLE_LED_FLASHER_DEMO_ONLY to 0. * * >>>>>> NOTE 2: <<<<<< * * In addition to the normal set of standard demo tasks, the comprehensive test * makes heavy use of the floating point unit, and forces floating point * instructions to be used from interrupts that nest three deep. The nesting * starts from the tick hook function, resulting is an abnormally long context * switch time. This is done purely to stress test the FPU context switching * implementation, and that part of the test can be removed by setting * configUSE_TICK_HOOK to 0 in FreeRTOSConfig.h. ****************************************************************************** * * main() creates all the demo application tasks and software timers, then starts * the scheduler. The web documentation provides more details of the standard * demo application tasks, which provide no particular functionality, but do * provide a good example of how to use the FreeRTOS API. * * In addition to the standard demo tasks, the following tasks and tests are * defined and/or created within this file: * * "Reg test" tasks - These fill both the core and floating point registers with * known values, then check that each register maintains its expected value for * the lifetime of the task. Each task uses a different set of values. The reg * test tasks execute with a very low priority, so get preempted very * frequently. A register containing an unexpected value is indicative of an * error in the context switching mechanism. * * "Check" timer - The check software timer period is initially set to three * seconds. The callback function associated with the check software timer * checks that all the standard demo tasks, and the register check tasks, are * not only still executing, but are executing without reporting any errors. If * the check software timer discovers that a task has either stalled, or * reported an error, then it changes its own execution period from the initial * three seconds, to just 200ms. The check software timer callback function * also toggles an LED each time it is called. This provides a visual * indication of the system status: If the LED toggles every three seconds, * then no issues have been discovered. If the LED toggles every 200ms, then * an issue has been discovered with at least one task. * * Tick hook - The application tick hook is called from the schedulers tick * interrupt service routine when configUSE_TICK_HOOK is set to 1 in * FreeRTOSConfig.h. In this example, the tick hook is used to test the kernels * handling of the floating point units (FPU) context, both at the task level * and when nesting interrupts access the floating point unit registers. The * tick hook function first fills the FPU registers with a known value, it * then triggers a medium priority interrupt. The medium priority interrupt * fills the FPU registers with a different value, and triggers a high priority * interrupt. The high priority interrupt once again fills the the FPU