2 FreeRTOS V7.1.1 - Copyright (C) 2012 Real Time Engineers Ltd.
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5 ***************************************************************************
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7 * FreeRTOS tutorial books are available in pdf and paperback. *
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8 * Complete, revised, and edited pdf reference manuals are also *
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11 * Purchasing FreeRTOS documentation will not only help you, by *
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12 * ensuring you get running as quickly as possible and with an *
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13 * in-depth knowledge of how to use FreeRTOS, it will also help *
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14 * the FreeRTOS project to continue with its mission of providing *
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15 * professional grade, cross platform, de facto standard solutions *
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16 * for microcontrollers - completely free of charge! *
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18 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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20 * Thank you for using FreeRTOS, and thank you for your support! *
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22 ***************************************************************************
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25 This file is part of the FreeRTOS distribution.
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27 FreeRTOS is free software; you can redistribute it and/or modify it under
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28 the terms of the GNU General Public License (version 2) as published by the
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29 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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30 >>>NOTE<<< The modification to the GPL is included to allow you to
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31 distribute a combined work that includes FreeRTOS without being obliged to
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32 provide the source code for proprietary components outside of the FreeRTOS
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33 kernel. FreeRTOS is distributed in the hope that it will be useful, but
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34 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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35 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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36 more details. You should have received a copy of the GNU General Public
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37 License and the FreeRTOS license exception along with FreeRTOS; if not it
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38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
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39 by writing to Richard Barry, contact details for whom are available on the
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44 ***************************************************************************
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46 * Having a problem? Start by reading the FAQ "My application does *
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47 * not run, what could be wrong? *
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49 * http://www.FreeRTOS.org/FAQHelp.html *
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51 ***************************************************************************
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54 http://www.FreeRTOS.org - Documentation, training, latest information,
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55 license and contact details.
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57 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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58 including FreeRTOS+Trace - an indispensable productivity tool.
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60 Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
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61 the code with commercial support, indemnification, and middleware, under
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62 the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
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63 provide a safety engineered and independently SIL3 certified version under
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64 the SafeRTOS brand: http://www.SafeRTOS.com.
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67 /* High speed timer test as described in main.c. */
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70 /* Scheduler includes. */
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71 #include "FreeRTOS.h"
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73 /* The maximum value the 16bit timer can contain. */
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74 #define timerMAX_COUNT 0xffff
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76 /* The timer 2 interrupt handler. As this interrupt uses the FreeRTOS assembly
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77 entry point the IPL setting in the following function prototype has no effect.
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78 The interrupt priority is set by ConfigIntTimer2() in vSetupTimerTest(). */
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79 void __attribute__( (interrupt(ipl0), vector(_TIMER_2_VECTOR))) vT2InterruptWrapper( void );
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81 /*-----------------------------------------------------------*/
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83 /* Incremented every 20,000 interrupts, so should count in seconds. */
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84 unsigned long ulHighFrequencyTimerInterrupts = 0;
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86 /* The frequency at which the timer is interrupting. */
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87 static unsigned long ulFrequencyHz;
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89 /*-----------------------------------------------------------*/
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91 void vSetupTimerTest( unsigned short usFrequencyHz )
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93 /* Remember the frequency so it can be used from the ISR. */
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94 ulFrequencyHz = ( unsigned long ) usFrequencyHz;
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96 /* T2 is used to generate interrupts above the kernel and max syscall interrupt
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101 /* Timer 2 is going to interrupt at usFrequencyHz Hz. */
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102 PR2 = ( unsigned short ) ( ( configPERIPHERAL_CLOCK_HZ / ( unsigned long ) usFrequencyHz ) - 1 );
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104 /* Setup timer 2 interrupt priority to be above the kernel priority so
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105 the timer jitter is not effected by the kernel activity. */
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106 ConfigIntTimer2( T2_INT_ON | ( configMAX_SYSCALL_INTERRUPT_PRIORITY + 1 ) );
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108 /* Clear the interrupt as a starting condition. */
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111 /* Enable the interrupt. */
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114 /* Start the timer. */
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117 /*-----------------------------------------------------------*/
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119 void vT2InterruptHandler( void )
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121 static unsigned long ulCalls = 0;
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124 if( ulCalls >= ulFrequencyHz )
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126 /* Increment the count that will be shown on the LCD.
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127 The increment occurs once every 20,000 interrupts so
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128 ulHighFrequencyTimerInterrupts should count in seconds. */
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129 ulHighFrequencyTimerInterrupts++;
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133 /* Clear the timer interrupt. */
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134 IFS0CLR = _IFS0_T2IF_MASK;
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