| /* | |
| FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd. | |
| All rights reserved | |
| VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. | |
| *************************************************************************** | |
| * * | |
| * FreeRTOS provides completely free yet professionally developed, * | |
| * robust, strictly quality controlled, supported, and cross * | |
| * platform software that has become a de facto standard. * | |
| * * | |
| * Help yourself get started quickly and support the FreeRTOS * | |
| * project by purchasing a FreeRTOS tutorial book, reference * | |
| * manual, or both from: http://www.FreeRTOS.org/Documentation * | |
| * * | |
| * Thank you! * | |
| * * | |
| *************************************************************************** | |
| 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. Full license text is available from the following | |
| link: http://www.freertos.org/a00114.html | |
| 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, books, training, latest versions, | |
| license and Real Time Engineers Ltd. contact details. | |
| http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products, | |
| including FreeRTOS+Trace - an indispensable productivity tool, a DOS | |
| compatible FAT file system, and our tiny thread aware UDP/IP stack. | |
| http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High | |
| Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS | |
| licenses offer ticketed support, indemnification and middleware. | |
| http://www.SafeRTOS.com - High Integrity Systems also provide a safety | |
| engineered and independently SIL3 certified version for use in safety and | |
| mission critical applications that require provable dependability. | |
| 1 tab == 4 spaces! | |
| */ | |
| /* 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 short ) 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 vSetupHighFrequencyTimer( void ); | |
| /* Stores the value of the maximum recorded jitter between interrupts. */ | |
| volatile unsigned short usMaxJitter = 0; | |
| /* Variable that counts at 20KHz to provide the time base for the run time | |
| stats. */ | |
| unsigned long ulRunTimeStatsClock = 0UL; | |
| /*-----------------------------------------------------------*/ | |
| void vSetupHighFrequencyTimer( 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 short ) ( 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 short ) 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 TIM2_IRQHandler( void ) | |
| { | |
| static unsigned short usLastCount = 0, usSettleCount = 0, usMaxDifference = 0; | |
| unsigned short 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; | |
| /* Keep a count of the number of interrupts as a time base for the run time | |
| stats collection. */ | |
| ulRunTimeStatsClock++; | |
| TIM_ClearITPendingBit( TIM2, TIM_IT_Update ); | |
| } | |