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/*
FreeRTOS.org V5.1.2 - 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 as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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 can be applied should you wish 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 of how and when the exception
can be applied.
***************************************************************************
***************************************************************************
* *
* 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. *
* *
***************************************************************************
***************************************************************************
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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