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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [RX600_RX62N-RSK_GNURX/] [RTOSDemo/] [HighFrequencyTimerTest.c] - Blame information for rev 585

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1 585 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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 * High frequency timer test as described in main.c.
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 */
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/* Scheduler includes. */
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#include "FreeRTOS.h"
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/* Hardware specifics. */
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#include "iodefine.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  ( ( unsigned short ) ( ( configPERIPHERAL_CLOCK_HZ / 8UL ) / timerINTERRUPT_FREQUENCY ) )
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/* The highest available interrupt priority. */
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#define timerHIGHEST_PRIORITY                   ( 15 )
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/* Misc defines. */
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#define timerTIMER_3_COUNT_VALUE                ( *( ( unsigned short * ) 0x8801a ) ) /*( CMT3.CMCNT )*/
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/*-----------------------------------------------------------*/
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/* Interrupt handler in which the jitter is measured. */
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void vTimer2_ISR_Handler( void ) __attribute__((interrupt));
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/* Stores the value of the maximum recorded jitter between interrupts.  This is
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displayed on one of the served web pages. */
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volatile unsigned short usMaxJitter = 0;
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/* Counts the number of high frequency interrupts - used to generate the run
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time stats. */
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volatile unsigned long ulHighFrequencyTickCount = 0UL;
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/*-----------------------------------------------------------*/
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void vSetupHighFrequencyTimer( void )
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{
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        /* Timer CMT2 is used to generate the interrupts, and CMT3 is used
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        to measure the jitter. */
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        /* Enable compare match timer 2 and 3. */
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        MSTP( CMT2 ) = 0;
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        MSTP( CMT3 ) = 0;
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        /* Interrupt on compare match. */
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        CMT2.CMCR.BIT.CMIE = 1;
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        /* Set the compare match value. */
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        CMT2.CMCOR = ( unsigned short ) ( ( ( configPERIPHERAL_CLOCK_HZ / timerINTERRUPT_FREQUENCY ) -1 ) / 8 );
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        /* Divide the PCLK by 8. */
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        CMT2.CMCR.BIT.CKS = 0;
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        CMT3.CMCR.BIT.CKS = 0;
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        /* Enable the interrupt... */
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        _IEN( _CMT2_CMI2 ) = 1;
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        /* ...and set its priority to the maximum possible, this is above the priority
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        set by configMAX_SYSCALL_INTERRUPT_PRIORITY so will nest. */
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        _IPR( _CMT2_CMI2 ) = timerHIGHEST_PRIORITY;
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        /* Start the timers. */
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        CMT.CMSTR1.BIT.STR2 = 1;
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        CMT.CMSTR1.BIT.STR3 = 1;
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}
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/*-----------------------------------------------------------*/
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void vTimer2_ISR_Handler( void )
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{
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volatile unsigned short usCurrentCount;
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static unsigned short usMaxCount = 0;
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static unsigned long ulErrorCount = 0UL;
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        /* This is the highest priority interrupt in the system, so there is no
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        advantage to re-enabling interrupts here.
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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.  First stop the clock. */
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        CMT.CMSTR1.BIT.STR3 = 0;
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        portNOP();
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        portNOP();
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        usCurrentCount = timerTIMER_3_COUNT_VALUE;
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        /* Is this the largest count we have measured yet? */
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        if( usCurrentCount > usMaxCount )
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        {
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                if( usCurrentCount > timerEXPECTED_DIFFERENCE_VALUE )
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                {
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                        usMaxJitter = usCurrentCount - timerEXPECTED_DIFFERENCE_VALUE;
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                }
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                else
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                {
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                        /* This should not happen! */
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                        ulErrorCount++;
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                }
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                usMaxCount = usCurrentCount;
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        }
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        /* Used to generate the run time stats. */
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        ulHighFrequencyTickCount++;
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        /* Clear the timer. */
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        timerTIMER_3_COUNT_VALUE = 0;
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        /* Then start the clock again. */
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        CMT.CMSTR1.BIT.STR3 = 1;
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}
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