Subversion Repositories openrisc_2011-10-31

/*
    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
 
    ***************************************************************************
    *                                                                         *
    * If you are:                                                             *
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    *    + New to FreeRTOS,                                                   *
    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
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    *                                                                         *
    * then take a look at the FreeRTOS books - available as PDF or paperback  *
    *                                                                         *
    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
    *                  http://www.FreeRTOS.org/Documentation                  *
    *                                                                         *
    * A pdf reference manual is also available.  Both are usually delivered   *
    * to your inbox within 20 minutes to two hours when purchased between 8am *
    * and 8pm GMT (although please allow up to 24 hours in case of            *
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    ***************************************************************************
 
    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 exception 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!
 
    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.
*/
 
/*
 * THIS DEMO APPLICATION REQUIRES A LOOPBACK CONNECTOR TO BE FITTED TO THE PIC
 * USART PORT - connect pin 2 to pin 3 on J2.
 *
 * Instead of the normal single demo application, the PIC18F demo is split 
 * into several smaller programs of which this is the third.  This enables the 
 * demo's to be executed on the RAM limited 40 pin devices.  The 64 and 80 pin 
 * devices require a more costly development platform and are not so readily 
 * available.
 *
 * The RTOSDemo3 project is configured for a PIC18F452 device.  Main3.c starts
 * 5 tasks (including the idle task).
 * 
 * The first task repeatedly transmits a string of characters on the PIC USART
 * port.  The second task receives the characters, checking that the correct
 * sequence is maintained (i.e. what is transmitted is identical to that 
 * received).  Each transmitted and each received character causes an LED to 
 * flash.  See demo/common/minimal/comtest. c for more information.
 *
 * The third task continuously performs a 32 bit calculation.  This is a good
 * test of the context switch mechanism as the 8 bit architecture requires 
 * the use of several file registers to perform the 32 bit operations.  See
 * demo/common/minimal/integer. c for more information.
 *
 * The third task is the check task.  This periodically checks that the other
 * tasks are still running and have not experienced any errors.  If no errors
 * have been reported by either the comms or integer tasks an LED is flashed
 * with a frequency mainNO_ERROR_CHECK_PERIOD.  If an error is discovered the 
 * frequency is increased to mainERROR_FLASH_RATE.
 *
 * The check task also provides a visual indication of a system reset by
 * flashing the one remaining LED (mainRESET_LED) when it starts.  After 
 * this initial flash mainRESET_LED should remain off.
 *
 * http://www.FreeRTOS.org contains important information on the use of the 
 * PIC18F port.
 */
 
/*
Changes from V2.0.0
 
	+ Delay periods are now specified using variables and constants of
	  portTickType rather than unsigned long.
*/
 
/* Scheduler include files. */
#include "FreeRTOS.h"
#include "task.h"
 
/* Demo app include files. */
#include "partest.h"
#include "serial.h"
#include "comtest.h"
#include "integer.h"
 
/* Priority definitions for the LED tasks.  Other tasks just use the idle
priority. */
#define mainCOMM_TEST_PRIORITY			( tskIDLE_PRIORITY + ( unsigned portBASE_TYPE ) 2 )
#define mainCHECK_TASK_PRIORITY			( tskIDLE_PRIORITY + ( unsigned portBASE_TYPE ) 3 )
 
/* The period between executions of the check task before and after an error
has been discovered.  If an error has been discovered the check task runs
more frequently - increasing the LED flash rate. */
#define mainNO_ERROR_CHECK_PERIOD		( ( portTickType ) 1000 / portTICK_RATE_MS )
#define mainERROR_CHECK_PERIOD			( ( portTickType ) 100 / portTICK_RATE_MS )
 
/* The period for which mainRESET_LED remain on every reset. */
#define mainRESET_LED_PERIOD			( ( portTickType ) 500 / portTICK_RATE_MS )
 
/* The LED that is toggled whenever a character is transmitted.
mainCOMM_TX_RX_LED + 1 will be toggled every time a character is received. */
#define mainCOMM_TX_RX_LED				( ( unsigned portBASE_TYPE ) 2 )
 
/* The LED that is flashed by the check task at a rate that indicates the 
error status. */
#define mainCHECK_TASK_LED				( ( unsigned portBASE_TYPE ) 1 )
 
/* The LED that is flashed once upon every reset. */
#define mainRESET_LED					( ( unsigned portBASE_TYPE ) 0 )
 
/* Constants required for the communications. */
#define mainCOMMS_QUEUE_LENGTH			( ( unsigned portBASE_TYPE ) 5 )
#define mainBAUD_RATE					( ( unsigned long ) 57600 )
/*-----------------------------------------------------------*/
 
/* 
 * Task function which periodically checks the other tasks for errors.  Flashes
 * an LED at a rate that indicates whether an error has ever been detected. 
 */
static void vErrorChecks( void *pvParameters );
 
/*-----------------------------------------------------------*/
 
/* Creates the tasks, then starts the scheduler. */
void main( void )
{
	/* Initialise the required hardware. */
	vParTestInitialise();
 
	/* Initialise the block memory allocator. */
	vPortInitialiseBlocks();
 
	/* Start the standard comtest tasks as defined in demo/common/minimal. */
	vAltStartComTestTasks( mainCOMM_TEST_PRIORITY, mainBAUD_RATE, mainCOMM_TX_RX_LED );
 
	/* Start the standard 32bit calculation task as defined in
	demo/common/minimal. */
	vStartIntegerMathTasks( tskIDLE_PRIORITY );
 
	/* Start the check task defined in this file. */
	xTaskCreate( vErrorChecks, ( const char * const ) "Check", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY, NULL );
 
	/* Start the scheduler.  This will never return. */
	vTaskStartScheduler();
}
/*-----------------------------------------------------------*/
 
static void vErrorChecks( void *pvParameters )
{
portTickType xDelayTime = mainNO_ERROR_CHECK_PERIOD;
volatile unsigned long ulDummy = 3UL;
 
	/* Toggle the LED so we can see when a reset occurs. */
	vParTestSetLED( mainRESET_LED, pdTRUE );
	vTaskDelay( mainRESET_LED_PERIOD );
	vParTestSetLED( mainRESET_LED, pdFALSE );
 
	/* Cycle for ever, delaying then checking all the other tasks are still
	operating without error. */
	for( ;; )
	{
		/* Wait until it is time to check the other tasks. */
		vTaskDelay( xDelayTime );
 
		/* Perform an integer calculation - just to ensure the registers
		get used.  The result is not important. */
		ulDummy *= 3UL;
 
		/* Check all the other tasks are running, and running without ever
		having an error.  The delay period is lowered if an error is reported,
		causing the LED to flash at a higher rate. */
		if( xAreIntegerMathsTaskStillRunning() == pdFALSE )
		{
			xDelayTime = mainERROR_CHECK_PERIOD;
		}
 
		if( xAreComTestTasksStillRunning() == pdFALSE )
		{
			xDelayTime = mainERROR_CHECK_PERIOD;
		}
 
		/* Flash the LED for visual feedback.  The rate of the flash will 
		indicate the health of the system. */
		vParTestToggleLED( mainCHECK_TASK_LED );
	}
}
/*-----------------------------------------------------------*/