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121 lines
4.3 KiB
C
121 lines
4.3 KiB
C
/*
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FreeRTOS.org V5.2.0 - Copyright (C) 2003-2009 Richard Barry.
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This file is part of the FreeRTOS.org distribution.
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FreeRTOS.org is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License (version 2) as published
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by the Free Software Foundation and modified by the FreeRTOS exception.
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FreeRTOS.org is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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more details.
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You should have received a copy of the GNU General Public License along
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with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59
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Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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A special exception to the GPL is included to allow you to distribute a
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combined work that includes FreeRTOS.org without being obliged to provide
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the source code for any proprietary components. See the licensing section
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of http://www.FreeRTOS.org for full details.
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***************************************************************************
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* *
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* Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
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* *
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* This is a concise, step by step, 'hands on' guide that describes both *
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* general multitasking concepts and FreeRTOS specifics. It presents and *
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* explains numerous examples that are written using the FreeRTOS API. *
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* Full source code for all the examples is provided in an accompanying *
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* .zip file. *
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* *
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***************************************************************************
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1 tab == 4 spaces!
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Please ensure to read the configuration and relevant port sections of the
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online documentation.
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http://www.FreeRTOS.org - Documentation, latest information, license and
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contact details.
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http://www.SafeRTOS.com - A version that is certified for use in safety
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critical systems.
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http://www.OpenRTOS.com - Commercial support, development, porting,
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licensing and training services.
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*/
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/* High speed timer test as described in main.c. */
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/* Scheduler includes. */
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#include "FreeRTOS.h"
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/* The maximum value the 16bit timer can contain. */
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#define timerMAX_COUNT 0xffff
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/* The timer 2 interrupt handler. */
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void __attribute__( (interrupt(ipl0), vector(_TIMER_2_VECTOR))) vT2InterruptWrapper( void );
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/*-----------------------------------------------------------*/
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/* Incremented every 20,000 interrupts, so should count in seconds. */
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unsigned portLONG ulHighFrequencyTimerInterrupts = 0;
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/* The frequency at which the timer is interrupting. */
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static unsigned portLONG ulFrequencyHz;
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/*-----------------------------------------------------------*/
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void vSetupTimerTest( unsigned portSHORT usFrequencyHz )
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{
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/* Remember the frequency so it can be used from the ISR. */
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ulFrequencyHz = ( unsigned portLONG ) usFrequencyHz;
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/* T2 is used to generate interrupts above the kernel and max syscall interrupt
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priority. */
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T2CON = 0;
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TMR2 = 0;
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/* Timer 2 is going to interrupt at usFrequencyHz Hz. */
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PR2 = ( unsigned portSHORT ) ( ( configPERIPHERAL_CLOCK_HZ / ( unsigned portLONG ) usFrequencyHz ) - 1 );
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/* Setup timer 2 interrupt priority to be above the kernel priority so
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the timer jitter is not effected by the kernel activity. */
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ConfigIntTimer2( T2_INT_ON | ( configMAX_SYSCALL_INTERRUPT_PRIORITY + 1 ) );
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/* Clear the interrupt as a starting condition. */
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IFS0bits.T2IF = 0;
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/* Enable the interrupt. */
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IEC0bits.T2IE = 1;
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/* Start the timer. */
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T2CONbits.TON = 1;
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}
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/*-----------------------------------------------------------*/
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void vT2InterruptHandler( void )
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{
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static unsigned portLONG ulCalls = 0;
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++ulCalls;
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if( ulCalls >= ulFrequencyHz )
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{
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/* Increment the count that will be shown on the LCD.
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The increment occurs once every 20,000 interrupts so
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ulHighFrequencyTimerInterrupts should count in seconds. */
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ulHighFrequencyTimerInterrupts++;
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ulCalls = 0;
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}
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/* Clear the timer interrupt. */
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IFS0bits.T2IF = 0;
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}
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