2 FreeRTOS.org V5.2.0 - Copyright (C) 2003-2009 Richard Barry.
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4 This file is part of the FreeRTOS.org distribution.
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6 FreeRTOS.org is free software; you can redistribute it and/or modify it
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7 under the terms of the GNU General Public License (version 2) as published
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8 by the Free Software Foundation and modified by the FreeRTOS exception.
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10 FreeRTOS.org is distributed in the hope that it will be useful, but WITHOUT
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11 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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12 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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15 You should have received a copy of the GNU General Public License along
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16 with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59
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17 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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19 A special exception to the GPL is included to allow you to distribute a
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20 combined work that includes FreeRTOS.org without being obliged to provide
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21 the source code for any proprietary components. See the licensing section
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22 of http://www.FreeRTOS.org for full details.
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25 ***************************************************************************
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27 * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
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29 * This is a concise, step by step, 'hands on' guide that describes both *
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30 * general multitasking concepts and FreeRTOS specifics. It presents and *
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31 * explains numerous examples that are written using the FreeRTOS API. *
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32 * Full source code for all the examples is provided in an accompanying *
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35 ***************************************************************************
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39 Please ensure to read the configuration and relevant port sections of the
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40 online documentation.
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42 http://www.FreeRTOS.org - Documentation, latest information, license and
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45 http://www.SafeRTOS.com - A version that is certified for use in safety
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48 http://www.OpenRTOS.com - Commercial support, development, porting,
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49 licensing and training services.
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52 /* High speed timer test as described in main.c. */
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55 /* Scheduler includes. */
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56 #include "FreeRTOS.h"
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58 /* The maximum value the 16bit timer can contain. */
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59 #define timerMAX_COUNT 0xffff
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61 /* The timer 2 interrupt handler. */
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62 void __attribute__( (interrupt(ipl0), vector(_TIMER_2_VECTOR))) vT2InterruptWrapper( void );
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64 /*-----------------------------------------------------------*/
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66 /* Incremented every 20,000 interrupts, so should count in seconds. */
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67 unsigned portLONG ulHighFrequencyTimerInterrupts = 0;
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69 /* The frequency at which the timer is interrupting. */
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70 static unsigned portLONG ulFrequencyHz;
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72 /*-----------------------------------------------------------*/
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74 void vSetupTimerTest( unsigned portSHORT usFrequencyHz )
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76 /* Remember the frequency so it can be used from the ISR. */
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77 ulFrequencyHz = ( unsigned portLONG ) usFrequencyHz;
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79 /* T2 is used to generate interrupts above the kernel and max syscall interrupt
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84 /* Timer 2 is going to interrupt at usFrequencyHz Hz. */
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85 PR2 = ( unsigned portSHORT ) ( ( configPERIPHERAL_CLOCK_HZ / ( unsigned portLONG ) usFrequencyHz ) - 1 );
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87 /* Setup timer 2 interrupt priority to be above the kernel priority so
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88 the timer jitter is not effected by the kernel activity. */
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89 ConfigIntTimer2( T2_INT_ON | ( configMAX_SYSCALL_INTERRUPT_PRIORITY + 1 ) );
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91 /* Clear the interrupt as a starting condition. */
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94 /* Enable the interrupt. */
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97 /* Start the timer. */
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100 /*-----------------------------------------------------------*/
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102 void vT2InterruptHandler( void )
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104 static unsigned portLONG ulCalls = 0;
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107 if( ulCalls >= ulFrequencyHz )
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109 /* Increment the count that will be shown on the LCD.
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110 The increment occurs once every 20,000 interrupts so
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111 ulHighFrequencyTimerInterrupts should count in seconds. */
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112 ulHighFrequencyTimerInterrupts++;
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116 /* Clear the timer interrupt. */
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