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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [Common/] [Minimal/] [flash.c] - Blame information for rev 609

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1 606 jeremybenn
/*
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    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
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    ***************************************************************************
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    *                                                                         *
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    * If you are:                                                             *
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    *                                                                         *
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    *    + New to FreeRTOS,                                                   *
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    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
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    *    + Looking for basic training,                                        *
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    *    + Wanting to improve your FreeRTOS skills and productivity           *
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    *                                                                         *
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    * then take a look at the FreeRTOS books - available as PDF or paperback  *
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    *                                                                         *
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    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
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    *                  http://www.FreeRTOS.org/Documentation                  *
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    *                                                                         *
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    * A pdf reference manual is also available.  Both are usually delivered   *
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    * to your inbox within 20 minutes to two hours when purchased between 8am *
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    * and 8pm GMT (although please allow up to 24 hours in case of            *
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    * exceptional circumstances).  Thank you for your support!                *
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    *                                                                         *
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    ***************************************************************************
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    This file is part of the FreeRTOS distribution.
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    FreeRTOS is free software; you can redistribute it and/or modify it under
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    the terms of the GNU General Public License (version 2) as published by the
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    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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    ***NOTE*** The exception to the GPL is included to allow you to distribute
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    a combined work that includes FreeRTOS without being obliged to provide the
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    source code for proprietary components outside of the FreeRTOS kernel.
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    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
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    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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    more details. You should have received a copy of the GNU General Public
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    License and the FreeRTOS license exception along with FreeRTOS; if not it
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    can be viewed here: http://www.freertos.org/a00114.html and also obtained
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    by writing to Richard Barry, contact details for whom are available on the
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    FreeRTOS WEB site.
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    1 tab == 4 spaces!
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    http://www.FreeRTOS.org - Documentation, latest information, license and
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    contact details.
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    http://www.SafeRTOS.com - A version that is certified for use in safety
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    critical systems.
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    http://www.OpenRTOS.com - Commercial support, development, porting,
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    licensing and training services.
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*/
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/**
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 * This version of flash .c is for use on systems that have limited stack space
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 * and no display facilities.  The complete version can be found in the
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 * Demo/Common/Full directory.
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 *
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 * Three tasks are created, each of which flash an LED at a different rate.  The first
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 * LED flashes every 200ms, the second every 400ms, the third every 600ms.
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 *
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 * The LED flash tasks provide instant visual feedback.  They show that the scheduler
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 * is still operational.
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 *
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 */
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#include <stdlib.h>
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/* Scheduler include files. */
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#include "FreeRTOS.h"
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#include "task.h"
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/* Demo program include files. */
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#include "partest.h"
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#include "flash.h"
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#define ledSTACK_SIZE           configMINIMAL_STACK_SIZE
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#define ledNUMBER_OF_LEDS       ( 3 )
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#define ledFLASH_RATE_BASE      ( ( portTickType ) 333 )
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/* Variable used by the created tasks to calculate the LED number to use, and
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the rate at which they should flash the LED. */
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static volatile unsigned portBASE_TYPE uxFlashTaskNumber = 0;
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/* The task that is created three times. */
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static portTASK_FUNCTION_PROTO( vLEDFlashTask, pvParameters );
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/*-----------------------------------------------------------*/
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void vStartLEDFlashTasks( unsigned portBASE_TYPE uxPriority )
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{
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signed portBASE_TYPE xLEDTask;
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        /* Create the three tasks. */
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        for( xLEDTask = 0; xLEDTask < ledNUMBER_OF_LEDS; ++xLEDTask )
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        {
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                /* Spawn the task. */
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                xTaskCreate( vLEDFlashTask, ( signed char * ) "LEDx", ledSTACK_SIZE, NULL, uxPriority, ( xTaskHandle * ) NULL );
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        }
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}
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/*-----------------------------------------------------------*/
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static portTASK_FUNCTION( vLEDFlashTask, pvParameters )
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{
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portTickType xFlashRate, xLastFlashTime;
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unsigned portBASE_TYPE uxLED;
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        /* The parameters are not used. */
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        ( void ) pvParameters;
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        /* Calculate the LED and flash rate. */
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        portENTER_CRITICAL();
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        {
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                /* See which of the eight LED's we should use. */
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                uxLED = uxFlashTaskNumber;
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                /* Update so the next task uses the next LED. */
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                uxFlashTaskNumber++;
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        }
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        portEXIT_CRITICAL();
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        xFlashRate = ledFLASH_RATE_BASE + ( ledFLASH_RATE_BASE * ( portTickType ) uxLED );
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        xFlashRate /= portTICK_RATE_MS;
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        /* We will turn the LED on and off again in the delay period, so each
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        delay is only half the total period. */
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        xFlashRate /= ( portTickType ) 2;
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        /* We need to initialise xLastFlashTime prior to the first call to
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        vTaskDelayUntil(). */
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        xLastFlashTime = xTaskGetTickCount();
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        for(;;)
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        {
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                /* Delay for half the flash period then turn the LED on. */
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                vTaskDelayUntil( &xLastFlashTime, xFlashRate );
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                vParTestToggleLED( uxLED );
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                /* Delay for half the flash period then turn the LED off. */
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                vTaskDelayUntil( &xLastFlashTime, xFlashRate );
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                vParTestToggleLED( uxLED );
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        }
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} /*lint !e715 !e818 !e830 Function definition must be standard for task creation. */
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