2 FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd.
\r
5 ***************************************************************************
\r
7 * FreeRTOS tutorial books are available in pdf and paperback. *
\r
8 * Complete, revised, and edited pdf reference manuals are also *
\r
11 * Purchasing FreeRTOS documentation will not only help you, by *
\r
12 * ensuring you get running as quickly as possible and with an *
\r
13 * in-depth knowledge of how to use FreeRTOS, it will also help *
\r
14 * the FreeRTOS project to continue with its mission of providing *
\r
15 * professional grade, cross platform, de facto standard solutions *
\r
16 * for microcontrollers - completely free of charge! *
\r
18 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
\r
20 * Thank you for using FreeRTOS, and thank you for your support! *
\r
22 ***************************************************************************
\r
25 This file is part of the FreeRTOS distribution.
\r
27 FreeRTOS is free software; you can redistribute it and/or modify it under
\r
28 the terms of the GNU General Public License (version 2) as published by the
\r
29 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
\r
30 >>>NOTE<<< The modification to the GPL is included to allow you to
\r
31 distribute a combined work that includes FreeRTOS without being obliged to
\r
32 provide the source code for proprietary components outside of the FreeRTOS
\r
33 kernel. FreeRTOS is distributed in the hope that it will be useful, but
\r
34 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
\r
35 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
\r
36 more details. You should have received a copy of the GNU General Public
\r
37 License and the FreeRTOS license exception along with FreeRTOS; if not it
\r
38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
\r
39 by writing to Richard Barry, contact details for whom are available on the
\r
44 ***************************************************************************
\r
46 * Having a problem? Start by reading the FAQ "My application does *
\r
47 * not run, what could be wrong? *
\r
49 * http://www.FreeRTOS.org/FAQHelp.html *
\r
51 ***************************************************************************
\r
54 http://www.FreeRTOS.org - Documentation, training, latest information,
\r
55 license and contact details.
\r
57 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
\r
58 including FreeRTOS+Trace - an indispensable productivity tool.
\r
60 Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
\r
61 the code with commercial support, indemnification, and middleware, under
\r
62 the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
\r
63 provide a safety engineered and independently SIL3 certified version under
\r
64 the SafeRTOS brand: http://www.SafeRTOS.com.
\r
67 /* High speed timer test as described in main.c. */
\r
69 /* Scheduler includes. */
\r
70 #include "FreeRTOS.h"
\r
72 /* Library includes. */
\r
73 #include "stm32f10x_lib.h"
\r
74 #include "stm32f10x_tim.h"
\r
75 #include "stm32f10x_map.h"
\r
77 /* The set frequency of the interrupt. Deviations from this are measured as
\r
79 #define timerINTERRUPT_FREQUENCY ( ( unsigned portSHORT ) 20000 )
\r
81 /* The expected time between each of the timer interrupts - if the jitter was
\r
83 #define timerEXPECTED_DIFFERENCE_VALUE ( configCPU_CLOCK_HZ / timerINTERRUPT_FREQUENCY )
\r
85 /* The highest available interrupt priority. */
\r
86 #define timerHIGHEST_PRIORITY ( 0 )
\r
89 #define timerMAX_32BIT_VALUE ( 0xffffffffUL )
\r
90 #define timerTIMER_1_COUNT_VALUE ( * ( ( unsigned long * ) ( TIMER1_BASE + 0x48 ) ) )
\r
92 /* The number of interrupts to pass before we start looking at the jitter. */
\r
93 #define timerSETTLE_TIME 5
\r
95 /*-----------------------------------------------------------*/
\r
98 * Configures the two timers used to perform the test.
\r
100 void vSetupTimerTest( void );
\r
102 /* Interrupt handler in which the jitter is measured. */
\r
103 void vTimer2IntHandler( void );
\r
105 /* Stores the value of the maximum recorded jitter between interrupts. */
\r
106 volatile unsigned portSHORT usMaxJitter = 0;
\r
108 /*-----------------------------------------------------------*/
\r
110 void vSetupTimerTest( void )
\r
112 unsigned long ulFrequency;
\r
113 TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
\r
114 NVIC_InitTypeDef NVIC_InitStructure;
\r
117 /* Enable timer clocks */
\r
118 RCC_APB1PeriphClockCmd( RCC_APB1Periph_TIM2, ENABLE );
\r
119 RCC_APB1PeriphClockCmd( RCC_APB1Periph_TIM3, ENABLE );
\r
121 /* Initialise data. */
\r
122 TIM_DeInit( TIM2 );
\r
123 TIM_DeInit( TIM3 );
\r
124 TIM_TimeBaseStructInit( &TIM_TimeBaseStructure );
\r
126 /* Time base configuration for timer 2 - which generates the interrupts. */
\r
127 ulFrequency = configCPU_CLOCK_HZ / timerINTERRUPT_FREQUENCY;
\r
128 TIM_TimeBaseStructure.TIM_Period = ( unsigned portSHORT ) ( ulFrequency & 0xffffUL );
\r
129 TIM_TimeBaseStructure.TIM_Prescaler = 0x0;
\r
130 TIM_TimeBaseStructure.TIM_ClockDivision = 0x0;
\r
131 TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
\r
132 TIM_TimeBaseInit( TIM2, &TIM_TimeBaseStructure );
\r
133 TIM_ARRPreloadConfig( TIM2, ENABLE );
\r
136 /* Configuration for timer 3 which is used as a high resolution time
\r
138 TIM_TimeBaseStructure.TIM_Period = ( unsigned portSHORT ) 0xffff;
\r
139 TIM_TimeBaseInit( TIM3, &TIM_TimeBaseStructure );
\r
140 TIM_ARRPreloadConfig( TIM3, ENABLE );
\r
142 /* Enable TIM2 IT. TIM3 does not generate an interrupt. */
\r
143 NVIC_InitStructure.NVIC_IRQChannel = TIM2_IRQChannel;
\r
144 NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
\r
145 NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = timerHIGHEST_PRIORITY;
\r
146 NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
\r
147 NVIC_Init( &NVIC_InitStructure );
\r
148 TIM_ITConfig( TIM2, TIM_IT_Update, ENABLE );
\r
150 /* Finally, enable both timers. */
\r
151 TIM_Cmd( TIM2, ENABLE );
\r
152 TIM_Cmd( TIM3, ENABLE );
\r
154 /*-----------------------------------------------------------*/
\r
156 void vTimer2IntHandler( void )
\r
158 static unsigned portSHORT usLastCount = 0, usSettleCount = 0, usMaxDifference = 0;
\r
159 unsigned portSHORT usThisCount, usDifference;
\r
161 /* Capture the free running timer 3 value as we enter the interrupt. */
\r
162 usThisCount = TIM3->CNT;
\r
164 if( usSettleCount >= timerSETTLE_TIME )
\r
166 /* What is the difference between the timer value in this interrupt
\r
167 and the value from the last interrupt. */
\r
168 usDifference = usThisCount - usLastCount;
\r
170 /* Store the difference in the timer values if it is larger than the
\r
171 currently stored largest value. The difference over and above the
\r
172 expected difference will give the 'jitter' in the processing of these
\r
174 if( usDifference > usMaxDifference )
\r
176 usMaxDifference = usDifference;
\r
177 usMaxJitter = usMaxDifference - timerEXPECTED_DIFFERENCE_VALUE;
\r
182 /* Don't bother storing any values for the first couple of
\r
187 /* Remember what the timer value was this time through, so we can calculate
\r
188 the difference the next time through. */
\r
189 usLastCount = usThisCount;
\r
191 TIM_ClearITPendingBit( TIM2, TIM_IT_Update );
\r