Subversion Repositories openrisc_2011-10-31

/*

    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.

    ***************************************************************************

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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

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*/

/*

 * 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 );

        }

}

/*-----------------------------------------------------------*/