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/*
FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd.
FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS tutorial books are available in pdf and paperback. *
* Complete, revised, and edited pdf reference manuals are also *
* available. *
* *
* Purchasing FreeRTOS documentation will not only help you, by *
* ensuring you get running as quickly as possible and with an *
* in-depth knowledge of how to use FreeRTOS, it will also help *
* the FreeRTOS project to continue with its mission of providing *
* professional grade, cross platform, de facto standard solutions *
* for microcontrollers - completely free of charge! *
* *
* >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
* *
* Thank you for using FreeRTOS, and thank you for your support! *
* *
***************************************************************************
This file is part of the FreeRTOS distribution.
FreeRTOS 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.
>>>NOTE<<< The modification to the GPL is included to allow you to
distribute a combined work that includes FreeRTOS without being obliged to
provide the source code for proprietary components outside of the FreeRTOS
kernel. FreeRTOS 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 and the FreeRTOS license exception along with FreeRTOS; if not it
can be viewed here: http://www.freertos.org/a00114.html and also obtained
by writing to Richard Barry, contact details for whom are available on the
FreeRTOS WEB site.
1 tab == 4 spaces!
***************************************************************************
* *
* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong?" *
* *
* http://www.FreeRTOS.org/FAQHelp.html *
* *
***************************************************************************
http://www.FreeRTOS.org - Documentation, training, latest versions, license
and contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool.
Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
the code with commercial support, indemnification, and middleware, under
the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
provide a safety engineered and independently SIL3 certified version under
the SafeRTOS brand: http://www.SafeRTOS.com.
*/
/* 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. As this interrupt uses the FreeRTOS assembly
entry point the IPL setting in the following function prototype has no effect.
The interrupt priority is set by ConfigIntTimer2() in vSetupTimerTest(). */
void __attribute__( (interrupt(ipl0), vector(_TIMER_2_VECTOR))) vT2InterruptWrapper( void );
/*-----------------------------------------------------------*/
/* Incremented every 20,000 interrupts, so should count in seconds. */
unsigned long ulHighFrequencyTimerInterrupts = 0;
/* The frequency at which the timer is interrupting. */
static unsigned long ulFrequencyHz;
/*-----------------------------------------------------------*/
void vSetupTimerTest( unsigned short usFrequencyHz )
{
/* Remember the frequency so it can be used from the ISR. */
ulFrequencyHz = ( unsigned long ) 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 short ) ( ( configPERIPHERAL_CLOCK_HZ / ( unsigned long ) 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 long 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. */
IFS0CLR = _IFS0_T2IF_MASK;
}
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