| /* | |
| 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. */ | |
| #include <device.h> | |
| /* Scheduler includes. */ | |
| #include "FreeRTOS.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 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. */ | |
| CY_ISR_PROTO(vTimer20KHzISR); | |
| /* Stores the value of the maximum recorded jitter between interrupts. */ | |
| volatile unsigned short usMaxJitter = 0; | |
| /*---------------------------------------------------------------------------*/ | |
| void vSetupTimerTest( void ) | |
| { | |
| /* Install the ISR. */ | |
| isrTimer_20KHz_TC_StartEx(vTimer20KHzISR); | |
| } | |
| /*---------------------------------------------------------------------------*/ | |
| CY_ISR(vTimer20KHzISR) | |
| { | |
| static unsigned short usLastCount = 0, usSettleCount = 0, usMaxDifference = 0; | |
| unsigned short usThisCount, usDifference; | |
| /* Capture the free running timer value as we enter the interrupt. */ | |
| usThisCount = Timer_48MHz_ReadCounter(); | |
| if( usSettleCount >= timerSETTLE_TIME ) | |
| { | |
| /* What is the difference between the timer value in this interrupt | |
| and the value from the last interrupt. Timer counts down. */ | |
| usDifference = usLastCount + ~usThisCount + 1; | |
| /* 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; | |
| /* Calculate the Jitter based on the difference we expect. */ | |
| 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; | |
| } | |
| /*---------------------------------------------------------------------------*/ |