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/*
FreeRTOS V7.5.1 - Copyright (C) 2013 Real Time Engineers Ltd.
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS provides completely free yet professionally developed, *
* robust, strictly quality controlled, supported, and cross *
* platform software that has become a de facto standard. *
* *
* Help yourself get started quickly and support the FreeRTOS *
* project by purchasing a FreeRTOS tutorial book, reference *
* manual, or both from: http://www.FreeRTOS.org/Documentation *
* *
* Thank you! *
* *
***************************************************************************
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. Full license text is available from the following
link: http://www.freertos.org/a00114.html
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, books, training, latest versions,
license and Real Time Engineers Ltd. contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool, a DOS
compatible FAT file system, and our tiny thread aware UDP/IP stack.
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
licenses offer ticketed support, indemnification and middleware.
http://www.SafeRTOS.com - High Integrity Systems also provide a safety
engineered and independently SIL3 certified version for use in safety and
mission critical applications that require provable dependability.
1 tab == 4 spaces!
*/
/*
* High frequency timer test as described in main.c.
*/
/* Scheduler includes. */
#include "FreeRTOS.h"
/* Hardware specifics. */
#include <iorx62n.h>
/* The set frequency of the interrupt. Deviations from this are measured as
the jitter. */
#define timerINTERRUPT_FREQUENCY ( 20000UL )
/* The expected time between each of the timer interrupts - if the jitter was
zero. */
#define timerEXPECTED_DIFFERENCE_VALUE ( ( unsigned short ) ( ( configPERIPHERAL_CLOCK_HZ / 8UL ) / timerINTERRUPT_FREQUENCY ) )
/* The highest available interrupt priority. */
#define timerHIGHEST_PRIORITY ( 15 )
/* Misc defines. */
#define timerTIMER_3_COUNT_VALUE ( *( ( unsigned short * ) 0x8801a ) ) /*( CMT3.CMCNT )*/
/*-----------------------------------------------------------*/
/* Interrupt handler in which the jitter is measured. */
__interrupt void vTimer2IntHandler( void );
/* Stores the value of the maximum recorded jitter between interrupts. */
volatile unsigned short usMaxJitter = 0;
/* Counts the number of high frequency interrupts - used to generate the run
time stats. */
volatile unsigned long ulHighFrequencyTickCount = 0UL;
/*-----------------------------------------------------------*/
void vSetupHighFrequencyTimer( void )
{
/* Timer CMT2 is used to generate the interrupts, and CMT3 is used
to measure the jitter. */
/* Enable compare match timer 2 and 3. */
MSTP( CMT2 ) = 0;
MSTP( CMT3 ) = 0;
/* Interrupt on compare match. */
CMT2.CMCR.BIT.CMIE = 1;
/* Set the compare match value. */
CMT2.CMCOR = ( unsigned short ) ( ( ( configPERIPHERAL_CLOCK_HZ / timerINTERRUPT_FREQUENCY ) -1 ) / 8 );
/* Divide the PCLK by 8. */
CMT2.CMCR.BIT.CKS = 0;
CMT3.CMCR.BIT.CKS = 0;
/* Enable the interrupt... */
_IEN( _CMT2_CMI2 ) = 1;
/* ...and set its priority to the maximum possible, this is above the priority
set by configMAX_SYSCALL_INTERRUPT_PRIORITY so will nest. */
_IPR( _CMT2_CMI2 ) = timerHIGHEST_PRIORITY;
/* Start the timers. */
CMT.CMSTR1.BIT.STR2 = 1;
CMT.CMSTR1.BIT.STR3 = 1;
}
/*-----------------------------------------------------------*/
#pragma vector = VECT_CMT2_CMI2
__interrupt void vTimer2IntHandler( void )
{
volatile unsigned short usCurrentCount;
static unsigned short usMaxCount = 0;
static unsigned long ulErrorCount = 0UL;
/* We use the timer 1 counter value to measure the clock cycles between
the timer 0 interrupts. First stop the clock. */
CMT.CMSTR1.BIT.STR3 = 0;
portNOP();
portNOP();
usCurrentCount = timerTIMER_3_COUNT_VALUE;
/* Is this the largest count we have measured yet? */
if( usCurrentCount > usMaxCount )
{
if( usCurrentCount > timerEXPECTED_DIFFERENCE_VALUE )
{
usMaxJitter = usCurrentCount - timerEXPECTED_DIFFERENCE_VALUE;
}
else
{
/* This should not happen! */
ulErrorCount++;
}
usMaxCount = usCurrentCount;
}
/* Used to generate the run time stats. */
ulHighFrequencyTickCount++;
/* Clear the timer. */
timerTIMER_3_COUNT_VALUE = 0;
/* Then start the clock again. */
CMT.CMSTR1.BIT.STR3 = 1;
}
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