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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [CORTEX_LM3Sxxxx_Eclipse/] [RTOSDemo/] [timertest.c] - Rev 601
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/* FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd. *************************************************************************** * * * If you are: * * * * + New to FreeRTOS, * * + Wanting to learn FreeRTOS or multitasking in general quickly * * + Looking for basic training, * * + Wanting to improve your FreeRTOS skills and productivity * * * * then take a look at the FreeRTOS books - available as PDF or paperback * * * * "Using the FreeRTOS Real Time Kernel - a Practical Guide" * * http://www.FreeRTOS.org/Documentation * * * * A pdf reference manual is also available. Both are usually delivered * * to your inbox within 20 minutes to two hours when purchased between 8am * * and 8pm GMT (although please allow up to 24 hours in case of * * exceptional circumstances). Thank you for your support! * * * *************************************************************************** This file is part of the FreeRTOS distribution. FreeRTOS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License (version 2) as published by the Free Software Foundation AND MODIFIED BY the FreeRTOS exception. ***NOTE*** The exception to the GPL is included to allow you to distribute a combined work that includes FreeRTOS without being obliged to provide the source code for proprietary components outside of the FreeRTOS kernel. FreeRTOS 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 and the FreeRTOS license exception along with FreeRTOS; if not it can be viewed here: http://www.freertos.org/a00114.html and also obtained by writing to Richard Barry, contact details for whom are available on the FreeRTOS WEB site. 1 tab == 4 spaces! 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. */ /* High speed timer test as described in main.c. */ /* Scheduler includes. */ #include "FreeRTOS.h" /* Library includes. */ #include "hw_ints.h" #include "hw_memmap.h" #include "hw_types.h" #include "interrupt.h" #include "sysctl.h" #include "lmi_timer.h" /* The set frequency of the interrupt. Deviations from this are measured as the jitter. */ #define timerINTERRUPT_FREQUENCY ( 20000UL ) /* The expected time between each of the timer interrupts - if the jitter was zero. */ #define timerEXPECTED_DIFFERENCE_VALUE ( configCPU_CLOCK_HZ / timerINTERRUPT_FREQUENCY ) /* The highest available interrupt priority. */ #define timerHIGHEST_PRIORITY ( 0 ) /* Misc defines. */ #define timerMAX_32BIT_VALUE ( 0xffffffffUL ) #define timerTIMER_1_COUNT_VALUE ( * ( ( unsigned long * ) ( TIMER1_BASE + 0x48 ) ) ) /*-----------------------------------------------------------*/ /* Interrupt handler in which the jitter is measured. */ void Timer0IntHandler( void ); /* Stores the value of the maximum recorded jitter between interrupts. */ volatile unsigned portLONG ulMaxJitter = 0UL; /* Counts the total number of times that the high frequency timer has 'ticked'. This value is used by the run time stats function to work out what percentage of CPU time each task is taking. */ volatile unsigned portLONG ulHighFrequencyTimerTicks = 0UL; /*-----------------------------------------------------------*/ void vSetupHighFrequencyTimer( void ) { unsigned long ulFrequency; /* Timer zero is used to generate the interrupts, and timer 1 is used to measure the jitter. */ SysCtlPeripheralEnable( SYSCTL_PERIPH_TIMER0 ); SysCtlPeripheralEnable( SYSCTL_PERIPH_TIMER1 ); TimerConfigure( TIMER0_BASE, TIMER_CFG_32_BIT_PER ); TimerConfigure( TIMER1_BASE, TIMER_CFG_32_BIT_PER ); /* Set the timer interrupt to be above the kernel - highest. */ IntPrioritySet( INT_TIMER0A, timerHIGHEST_PRIORITY ); /* Just used to measure time. */ TimerLoadSet(TIMER1_BASE, TIMER_A, timerMAX_32BIT_VALUE ); /* Ensure interrupts do not start until the scheduler is running. */ portDISABLE_INTERRUPTS(); /* The rate at which the timer will interrupt. */ ulFrequency = configCPU_CLOCK_HZ / timerINTERRUPT_FREQUENCY; TimerLoadSet( TIMER0_BASE, TIMER_A, ulFrequency ); IntEnable( INT_TIMER0A ); TimerIntEnable( TIMER0_BASE, TIMER_TIMA_TIMEOUT ); /* Enable both timers. */ TimerEnable( TIMER0_BASE, TIMER_A ); TimerEnable( TIMER1_BASE, TIMER_A ); } /*-----------------------------------------------------------*/ void Timer0IntHandler( void ) { unsigned portLONG ulDifference; volatile unsigned portLONG ulCurrentCount; static unsigned portLONG ulMaxDifference = 0, ulLastCount = 0; /* We use the timer 1 counter value to measure the clock cycles between the timer 0 interrupts. */ ulCurrentCount = timerTIMER_1_COUNT_VALUE; TimerIntClear( TIMER0_BASE, TIMER_TIMA_TIMEOUT ); if( ulCurrentCount < ulLastCount ) { /* How many times has timer 1 counted since the last interrupt? */ ulDifference = ulLastCount - ulCurrentCount; /* Is this the largest difference we have measured yet? */ if( ulDifference > ulMaxDifference ) { ulMaxDifference = ulDifference; ulMaxJitter = ulMaxDifference - timerEXPECTED_DIFFERENCE_VALUE; } } ulLastCount = ulCurrentCount; /* Keep a count of the total number of 20KHz ticks. This is used by the run time stats functionality to calculate how much CPU time is used by each task. */ ulHighFrequencyTimerTicks++; }
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