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