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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [CORTEX_LM3Sxxxx_IAR_Keil/] [timertest.c] - Blame information for rev 594

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1 581 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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/* High speed timer test as described in main.c. */
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/* Scheduler includes. */
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#include "FreeRTOS.h"
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/* Library includes. */
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#include "hw_ints.h"
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#include "hw_memmap.h"
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#include "hw_types.h"
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#include "interrupt.h"
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#include "sysctl.h"
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#include "lmi_timer.h"
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#include "hw_timer.h"
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/* The set frequency of the interrupt.  Deviations from this are measured as
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the jitter. */
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#define timerINTERRUPT_FREQUENCY                ( 20000UL )
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/* The expected time between each of the timer interrupts - if the jitter was
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zero. */
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#define timerEXPECTED_DIFFERENCE_VALUE  ( configCPU_CLOCK_HZ / timerINTERRUPT_FREQUENCY )
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/* The highest available interrupt priority. */
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#define timerHIGHEST_PRIORITY                   ( 0 )
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/* Misc defines. */
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#define timerMAX_32BIT_VALUE                    ( 0xffffffffUL )
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#define timerTIMER_1_COUNT_VALUE                ( * ( ( volatile unsigned long * ) ( ( unsigned portLONG ) TIMER1_BASE + 0x48UL ) ) )
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/*-----------------------------------------------------------*/
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/* Interrupt handler in which the jitter is measured. */
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void Timer0IntHandler( void );
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/* Stores the value of the maximum recorded jitter between interrupts. */
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volatile unsigned portLONG ulMaxJitter = 0;
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/*-----------------------------------------------------------*/
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void vSetupHighFrequencyTimer( void )
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{
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unsigned long ulFrequency;
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        /* Timer zero is used to generate the interrupts, and timer 1 is used
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        to measure the jitter. */
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        SysCtlPeripheralEnable( SYSCTL_PERIPH_TIMER0 );
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    SysCtlPeripheralEnable( SYSCTL_PERIPH_TIMER1 );
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    TimerConfigure( TIMER0_BASE, TIMER_CFG_32_BIT_PER );
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    TimerConfigure( TIMER1_BASE, TIMER_CFG_32_BIT_PER );
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        /* Set the timer interrupt to be above the kernel - highest. */
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        IntPrioritySet( INT_TIMER0A, timerHIGHEST_PRIORITY );
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        /* Just used to measure time. */
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    TimerLoadSet(TIMER1_BASE, TIMER_A, timerMAX_32BIT_VALUE );
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        /* Ensure interrupts do not start until the scheduler is running. */
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        portDISABLE_INTERRUPTS();
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        /* The rate at which the timer will interrupt. */
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        ulFrequency = configCPU_CLOCK_HZ / timerINTERRUPT_FREQUENCY;
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    TimerLoadSet( TIMER0_BASE, TIMER_A, ulFrequency );
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    IntEnable( INT_TIMER0A );
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    TimerIntEnable( TIMER0_BASE, TIMER_TIMA_TIMEOUT );
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        /* Enable both timers. */
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    TimerEnable( TIMER0_BASE, TIMER_A );
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    TimerEnable( TIMER1_BASE, TIMER_A );
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}
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/*-----------------------------------------------------------*/
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void Timer0IntHandler( void )
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{
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unsigned portLONG ulDifference;
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volatile unsigned portLONG ulCurrentCount;
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static unsigned portLONG ulMaxDifference = 0, ulLastCount = 0;
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        /* We use the timer 1 counter value to measure the clock cycles between
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        the timer 0 interrupts. */
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        ulCurrentCount = timerTIMER_1_COUNT_VALUE;
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        TimerIntClear( TIMER0_BASE, TIMER_TIMA_TIMEOUT );
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        if( ulCurrentCount < ulLastCount )
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        {
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                /* How many times has timer 1 counted since the last interrupt? */
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                ulDifference =  ulLastCount - ulCurrentCount;
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                /* Is this the largest difference we have measured yet? */
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                if( ulDifference > ulMaxDifference )
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                {
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                        ulMaxDifference = ulDifference;
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                        ulMaxJitter = ulMaxDifference - timerEXPECTED_DIFFERENCE_VALUE;
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                }
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        }
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        ulLastCount = ulCurrentCount;
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}
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