| /* | |
| FreeRTOS V7.3.0 - Copyright (C) 2012 Real Time Engineers Ltd. | |
| FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT | |
| http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. | |
| *************************************************************************** | |
| * * | |
| * FreeRTOS tutorial books are available in pdf and paperback. * | |
| * Complete, revised, and edited pdf reference manuals are also * | |
| * available. * | |
| * * | |
| * Purchasing FreeRTOS documentation will not only help you, by * | |
| * ensuring you get running as quickly as possible and with an * | |
| * in-depth knowledge of how to use FreeRTOS, it will also help * | |
| * the FreeRTOS project to continue with its mission of providing * | |
| * professional grade, cross platform, de facto standard solutions * | |
| * for microcontrollers - completely free of charge! * | |
| * * | |
| * >>> See http://www.FreeRTOS.org/Documentation for details. <<< * | |
| * * | |
| * Thank you for using FreeRTOS, and 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 modification 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! | |
| *************************************************************************** | |
| * * | |
| * Having a problem? Start by reading the FAQ "My application does * | |
| * not run, what could be wrong?" * | |
| * * | |
| * http://www.FreeRTOS.org/FAQHelp.html * | |
| * * | |
| *************************************************************************** | |
| http://www.FreeRTOS.org - Documentation, training, latest versions, license | |
| and contact details. | |
| http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, | |
| including FreeRTOS+Trace - an indispensable productivity tool. | |
| Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell | |
| the code with commercial support, indemnification, and middleware, under | |
| the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also | |
| provide a safety engineered and independently SIL3 certified version under | |
| the SafeRTOS brand: http://www.SafeRTOS.com. | |
| */ | |
| /* High speed timer test as described in main.c. */ | |
| /* Scheduler includes. */ | |
| #include "FreeRTOS.h" | |
| /* Library includes. */ | |
| #include "stm32f10x_lib.h" | |
| #include "stm32f10x_tim.h" | |
| #include "stm32f10x_map.h" | |
| /* The set frequency of the interrupt. Deviations from this are measured as | |
| the jitter. */ | |
| #define timerINTERRUPT_FREQUENCY ( ( unsigned portSHORT ) 20000 ) | |
| /* 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 ) ) ) | |
| /* The number of interrupts to pass before we start looking at the jitter. */ | |
| #define timerSETTLE_TIME 5 | |
| /*-----------------------------------------------------------*/ | |
| /* | |
| * Configures the two timers used to perform the test. | |
| */ | |
| void vSetupTimerTest( void ); | |
| /* Interrupt handler in which the jitter is measured. */ | |
| void vTimer2IntHandler( void ); | |
| /* Stores the value of the maximum recorded jitter between interrupts. */ | |
| volatile unsigned portSHORT usMaxJitter = 0; | |
| /*-----------------------------------------------------------*/ | |
| void vSetupTimerTest( void ) | |
| { | |
| unsigned long ulFrequency; | |
| TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure; | |
| NVIC_InitTypeDef NVIC_InitStructure; | |
| /* Enable timer clocks */ | |
| RCC_APB1PeriphClockCmd( RCC_APB1Periph_TIM2, ENABLE ); | |
| RCC_APB1PeriphClockCmd( RCC_APB1Periph_TIM3, ENABLE ); | |
| /* Initialise data. */ | |
| TIM_DeInit( TIM2 ); | |
| TIM_DeInit( TIM3 ); | |
| TIM_TimeBaseStructInit( &TIM_TimeBaseStructure ); | |
| /* Time base configuration for timer 2 - which generates the interrupts. */ | |
| ulFrequency = configCPU_CLOCK_HZ / timerINTERRUPT_FREQUENCY; | |
| TIM_TimeBaseStructure.TIM_Period = ( unsigned portSHORT ) ( ulFrequency & 0xffffUL ); | |
| TIM_TimeBaseStructure.TIM_Prescaler = 0x0; | |
| TIM_TimeBaseStructure.TIM_ClockDivision = 0x0; | |
| TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; | |
| TIM_TimeBaseInit( TIM2, &TIM_TimeBaseStructure ); | |
| TIM_ARRPreloadConfig( TIM2, ENABLE ); | |
| /* Configuration for timer 3 which is used as a high resolution time | |
| measurement. */ | |
| TIM_TimeBaseStructure.TIM_Period = ( unsigned portSHORT ) 0xffff; | |
| TIM_TimeBaseInit( TIM3, &TIM_TimeBaseStructure ); | |
| TIM_ARRPreloadConfig( TIM3, ENABLE ); | |
| /* Enable TIM2 IT. TIM3 does not generate an interrupt. */ | |
| NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQChannel; | |
| NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0; | |
| NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = timerHIGHEST_PRIORITY; | |
| NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; | |
| NVIC_Init( &NVIC_InitStructure ); | |
| TIM_ITConfig( TIM2, TIM_IT_Update, ENABLE ); | |
| /* Finally, enable both timers. */ | |
| TIM_Cmd( TIM2, ENABLE ); | |
| TIM_Cmd( TIM3, ENABLE ); | |
| } | |
| /*-----------------------------------------------------------*/ | |
| void vTimer2IntHandler( void ) | |
| { | |
| static unsigned portSHORT usLastCount = 0, usSettleCount = 0, usMaxDifference = 0; | |
| unsigned portSHORT usThisCount, usDifference; | |
| /* Capture the free running timer 3 value as we enter the interrupt. */ | |
| usThisCount = TIM3->CNT; | |
| if( usSettleCount >= timerSETTLE_TIME ) | |
| { | |
| /* What is the difference between the timer value in this interrupt | |
| and the value from the last interrupt. */ | |
| usDifference = usThisCount - usLastCount; | |
| /* Store the difference in the timer values if it is larger than the | |
| currently stored largest value. The difference over and above the | |
| expected difference will give the 'jitter' in the processing of these | |
| interrupts. */ | |
| if( usDifference > usMaxDifference ) | |
| { | |
| usMaxDifference = usDifference; | |
| usMaxJitter = usMaxDifference - timerEXPECTED_DIFFERENCE_VALUE; | |
| } | |
| } | |
| else | |
| { | |
| /* Don't bother storing any values for the first couple of | |
| interrupts. */ | |
| usSettleCount++; | |
| } | |
| /* Remember what the timer value was this time through, so we can calculate | |
| the difference the next time through. */ | |
| usLastCount = usThisCount; | |
| TIM_ClearITPendingBit( TIM2, TIM_IT_Update ); | |
| } | |