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/*
FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 Richard Barry.
This file is part of the FreeRTOS.org distribution.
FreeRTOS.org is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
FreeRTOS.org 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
along with FreeRTOS.org; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
A special exception to the GPL can be applied should you wish to distribute
a combined work that includes FreeRTOS.org, without being obliged to provide
the source code for any proprietary components. See the licensing section
of http://www.FreeRTOS.org for full details of how and when the exception
can be applied.
***************************************************************************
***************************************************************************
* *
* Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
* *
* This is a concise, step by step, 'hands on' guide that describes both *
* general multitasking concepts and FreeRTOS specifics. It presents and *
* explains numerous examples that are written using the FreeRTOS API. *
* Full source code for all the examples is provided in an accompanying *
* .zip file. *
* *
***************************************************************************
***************************************************************************
Please ensure to read the configuration and relevant port sections of the
online documentation.
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.
*/
#include "FreeRTOS.h"
#include "task.h"
__declspec(interrupt:0) void vPIT0InterruptHandler( void );
/* Constants used to configure the interrupts. */
#define portPRESCALE_VALUE 64
#define portPRESCALE_REG_SETTING ( 5 << 8 )
#define portPIT_INTERRUPT_ENABLED ( 0x08 )
#define configPIT0_INTERRUPT_VECTOR ( 55 )
/*
* FreeRTOS.org requires two interrupts - a tick interrupt generated from a
* timer source, and a spare interrupt vector used for context switching.
* The configuration below uses PIT0 for the former, and vector 16 for the
* latter. **IF YOUR APPLICATION HAS BOTH OF THESE INTERRUPTS FREE THEN YOU DO
* NOT NEED TO CHANGE ANY OF THIS CODE** - otherwise instructions are provided
* here for using alternative interrupt sources.
*
* To change the tick interrupt source:
*
* 1) Modify vApplicationSetupInterrupts() below to be correct for whichever
* peripheral is to be used to generate the tick interrupt.
*
* 2) Change the name of the function __cs3_isr_interrupt_119() defined within
* this file to be correct for the interrupt vector used by the timer peripheral.
* The name of the function should contain the vector number, so by default vector
* number 119 is being used.
*
* 3) Make sure the tick interrupt is cleared within the interrupt handler function.
* Currently __cs3_isr_interrupt_119() clears the PIT0 interrupt.
*
* To change the spare interrupt source:
*
* 1) Modify vApplicationSetupInterrupts() below to be correct for whichever
* interrupt vector is to be used. Make sure you use a spare interrupt on interrupt
* controller 0, otherwise the register used to request context switches will also
* require modification.
*
* 2) Change the definition of configYIELD_INTERRUPT_VECTOR within FreeRTOSConfig.h
* to be correct for your chosen interrupt vector.
*
* 3) Change the name of the function __cs3_isr_interrupt_127() within portasm.S
* to be correct for whichever vector number is being used. By default interrupt
* controller 0 number 16 is used, which corresponds to vector number 127.
*/
void vApplicationSetupInterrupts( void )
{
const unsigned portSHORT usCompareMatchValue = ( ( configCPU_CLOCK_HZ / portPRESCALE_VALUE ) / configTICK_RATE_HZ );
/* Configure interrupt priority and level and unmask interrupt for PIT0. */
MCF_INTC0_ICR55 = ( 1 | ( configKERNEL_INTERRUPT_PRIORITY << 3 ) );
MCF_INTC0_IMRH &= ~( MCF_INTC_IMRH_INT_MASK55 );
/* Do the same for vector 63 (interrupt controller 0. I don't think the
write to MCF_INTC0_IMRH is actually required here but is included for
completeness. */
MCF_INTC0_ICR16 = ( 0 | configKERNEL_INTERRUPT_PRIORITY << 3 );
MCF_INTC0_IMRL &= ~( MCF_INTC_IMRL_INT_MASK16 | 0x01 );
/* Configure PIT0 to generate the RTOS tick. */
MCF_PIT0_PCSR |= MCF_PIT_PCSR_PIF;
MCF_PIT0_PCSR = ( portPRESCALE_REG_SETTING | MCF_PIT_PCSR_PIE | MCF_PIT_PCSR_RLD | MCF_PIT_PCSR_EN );
MCF_PIT0_PMR = usCompareMatchValue;
}
/*-----------------------------------------------------------*/
__declspec(interrupt:0) void vPIT0InterruptHandler( void )
{
unsigned portLONG ulSavedInterruptMask;
/* Clear the PIT0 interrupt. */
MCF_PIT0_PCSR |= MCF_PIT_PCSR_PIF;
/* Increment the RTOS tick. */
ulSavedInterruptMask = portSET_INTERRUPT_MASK_FROM_ISR();
vTaskIncrementTick();
portCLEAR_INTERRUPT_MASK_FROM_ISR( ulSavedInterruptMask );
/* If we are using the pre-emptive scheduler then also request a
context switch as incrementing the tick could have unblocked a task. */
#if configUSE_PREEMPTION == 1
{
taskYIELD();
}
#endif
}
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