/* | |
FreeRTOS V9.0.1 - Copyright (C) 2017 Real Time Engineers Ltd. | |
All rights reserved | |
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. | |
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 on the following | |
link: http://www.freertos.org/a00114.html | |
*************************************************************************** | |
* * | |
* FreeRTOS provides completely free yet professionally developed, * | |
* robust, strictly quality controlled, supported, and cross * | |
* platform software that is more than just the market leader, it * | |
* is the industry's de facto standard. * | |
* * | |
* Help yourself get started quickly while simultaneously helping * | |
* to support the FreeRTOS project by purchasing a FreeRTOS * | |
* tutorial book, reference manual, or both: * | |
* http://www.FreeRTOS.org/Documentation * | |
* * | |
*************************************************************************** | |
http://www.FreeRTOS.org/FAQHelp.html - Having a problem? Start by reading | |
the FAQ page "My application does not run, what could be wrong?". Have you | |
defined configASSERT()? | |
http://www.FreeRTOS.org/support - In return for receiving this top quality | |
embedded software for free we request you assist our global community by | |
participating in the support forum. | |
http://www.FreeRTOS.org/training - Investing in training allows your team to | |
be as productive as possible as early as possible. Now you can receive | |
FreeRTOS training directly from Richard Barry, CEO of Real Time Engineers | |
Ltd, and the world's leading authority on the world's leading RTOS. | |
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.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate. | |
Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS. | |
http://www.OpenRTOS.com - Real Time Engineers ltd. license FreeRTOS to High | |
Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS | |
licenses offer ticketed support, indemnification and commercial 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 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(IPL0AUTO), 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. */ | |
IPC2bits.T2IP = ( 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; | |
} | |