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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [ColdFire_MCF52259_CodeWarrior/] [FreeRTOS_Tick_Setup.c] - Blame information for rev 595

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1 578 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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#include "FreeRTOS.h"
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#include "task.h"
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__declspec(interrupt:0) void vPIT0InterruptHandler( void );
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/* Constants used to configure the interrupts. */
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#define portPRESCALE_VALUE                      64
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#define portPRESCALE_REG_SETTING        ( 5 << 8 )
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#define portPIT_INTERRUPT_ENABLED       ( 0x08 )
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#define configPIT0_INTERRUPT_VECTOR     ( 55 )
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/*
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 * FreeRTOS.org requires two interrupts - a tick interrupt generated from a
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 * timer source, and a spare interrupt vector used for context switching.
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 * The configuration below uses PIT0 for the former, and vector 16 for the
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 * latter.  **IF YOUR APPLICATION HAS BOTH OF THESE INTERRUPTS FREE THEN YOU DO
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 * NOT NEED TO CHANGE ANY OF THIS CODE** - otherwise instructions are provided
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 * here for using alternative interrupt sources.
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 *
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 * To change the tick interrupt source:
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 *
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 *      1) Modify vApplicationSetupInterrupts() below to be correct for whichever
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 *      peripheral is to be used to generate the tick interrupt.  The name of the
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 *  handler function (currently vPIT0InterruptHandler()) should also be updated
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 *  to indicate which peripheral is generating the interrupt.
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 *
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 *      2) Make sure the interrupt source is cleared within the interrupt handler function.
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 *  Currently vPIT0InterruptHandler() clears the PIT0 interrupt.
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 *
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 *  3) Update the vector table within mcf5225x_vectors.s to install the tick
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 *  interrupt handler in the correct vector position.
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 *
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 * To change the spare interrupt source:
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 *
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 *  1) Modify vApplicationSetupInterrupts() below to be correct for whichever
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 *  interrupt vector is to be used.  Make sure you use a spare interrupt on interrupt
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 *  controller 0, otherwise the register used to request context switches will also
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 *  require modification.
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 *
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 *  2) Change the definition of configYIELD_INTERRUPT_VECTOR within FreeRTOSConfig.h
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 *  to be correct for your chosen interrupt vector.
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 *
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 *  3) Update the vector table within mcf5225x_vectors.s to install the handler
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 *  _vPortYieldISR() in the correct vector position (by default vector number 16 is
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 *  used).
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 */
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void vApplicationSetupInterrupts( void )
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{
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const unsigned portSHORT usCompareMatchValue = ( ( configCPU_CLOCK_HZ / portPRESCALE_VALUE ) / configTICK_RATE_HZ );
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    /* Configure interrupt priority and level and unmask interrupt for PIT0. */
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    MCF_INTC0_ICR55 = ( 1 | ( configKERNEL_INTERRUPT_PRIORITY << 3 ) );
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    MCF_INTC0_IMRH &= ~( MCF_INTC_IMRH_INT_MASK55 );
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    /* Do the same for vector 63 (interrupt controller 0.  I don't think the
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    write to MCF_INTC0_IMRH is actually required here but is included for
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    completeness. */
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    MCF_INTC0_ICR16 = ( 0 | configKERNEL_INTERRUPT_PRIORITY << 3 );
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    MCF_INTC0_IMRL &= ~( MCF_INTC_IMRL_INT_MASK16 | 0x01 );
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    /* Configure PIT0 to generate the RTOS tick. */
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    MCF_PIT0_PCSR |= MCF_PIT_PCSR_PIF;
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    MCF_PIT0_PCSR = ( portPRESCALE_REG_SETTING | MCF_PIT_PCSR_PIE | MCF_PIT_PCSR_RLD | MCF_PIT_PCSR_EN );
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        MCF_PIT0_PMR = usCompareMatchValue;
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}
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/*-----------------------------------------------------------*/
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__declspec(interrupt:0) void vPIT0InterruptHandler( void )
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{
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unsigned portLONG ulSavedInterruptMask;
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        /* Clear the PIT0 interrupt. */
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        MCF_PIT0_PCSR |= MCF_PIT_PCSR_PIF;
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        /* Increment the RTOS tick. */
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        ulSavedInterruptMask = portSET_INTERRUPT_MASK_FROM_ISR();
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                vTaskIncrementTick();
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        portCLEAR_INTERRUPT_MASK_FROM_ISR( ulSavedInterruptMask );
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        /* If we are using the pre-emptive scheduler then also request a
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        context switch as incrementing the tick could have unblocked a task. */
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        #if configUSE_PREEMPTION == 1
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        {
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                taskYIELD();
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        }
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        #endif
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}

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