/* | |
FreeRTOS V7.4.2 - Copyright (C) 2013 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 Real Time Engineers Ltd., 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, 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, and our new | |
fully thread aware and reentrant UDP/IP stack. | |
http://www.OpenRTOS.com - 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.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. | |
*/ | |
/* High speed timer test as described in main.c. */ | |
#include <device.h> | |
/* Scheduler includes. */ | |
#include "FreeRTOS.h" | |
/* The set frequency of the interrupt. Deviations from this are measured as | |
the jitter. */ | |
#define timerINTERRUPT_FREQUENCY ( ( unsigned portSHORT ) 20000 ) | |
/* The expected time between each of the timer interrupts - if the jitter was | |
zero. */ | |
#define timerEXPECTED_DIFFERENCE_VALUE ( configCPU_CLOCK_HZ / timerINTERRUPT_FREQUENCY ) | |
/* The number of interrupts to pass before we start looking at the jitter. */ | |
#define timerSETTLE_TIME 5 | |
/*---------------------------------------------------------------------------*/ | |
/* | |
* Configures the two timers used to perform the test. | |
*/ | |
void vSetupTimerTest( void ); | |
/* Interrupt handler in which the jitter is measured. */ | |
CY_ISR_PROTO(vTimer20KHzISR); | |
/* Stores the value of the maximum recorded jitter between interrupts. */ | |
volatile unsigned portSHORT usMaxJitter = 0; | |
/*---------------------------------------------------------------------------*/ | |
void vSetupTimerTest( void ) | |
{ | |
/* Install the ISR. */ | |
isrTimer_20KHz_TC_StartEx(vTimer20KHzISR); | |
} | |
/*---------------------------------------------------------------------------*/ | |
CY_ISR(vTimer20KHzISR) | |
{ | |
static unsigned short usLastCount = 0, usSettleCount = 0, usMaxDifference = 0; | |
unsigned short usThisCount, usDifference; | |
/* Capture the free running timer value as we enter the interrupt. */ | |
usThisCount = Timer_48MHz_ReadCounter(); | |
if( usSettleCount >= timerSETTLE_TIME ) | |
{ | |
/* What is the difference between the timer value in this interrupt | |
and the value from the last interrupt. Timer counts down. */ | |
usDifference = usLastCount + ~usThisCount + 1; | |
/* Store the difference in the timer values if it is larger than the | |
currently stored largest value. The difference over and above the | |
expected difference will give the 'jitter' in the processing of these | |
interrupts. */ | |
if( usDifference > usMaxDifference ) | |
{ | |
usMaxDifference = usDifference; | |
/* Calculate the Jitter based on the difference we expect. */ | |
usMaxJitter = usMaxDifference - timerEXPECTED_DIFFERENCE_VALUE; | |
} | |
} | |
else | |
{ | |
/* Don't bother storing any values for the first couple of | |
interrupts. */ | |
usSettleCount++; | |
} | |
/* Remember what the timer value was this time through, so we can calculate | |
the difference the next time through. */ | |
usLastCount = usThisCount; | |
} | |
/*---------------------------------------------------------------------------*/ |