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
68 * High frequency timer test as described in main.c.
\r
71 /* Scheduler includes. */
\r
72 #include "FreeRTOS.h"
\r
74 /* Hardware specifics. */
\r
75 #include <iorx62n.h>
\r
77 /* The set frequency of the interrupt. Deviations from this are measured as
\r
79 #define timerINTERRUPT_FREQUENCY ( 20000UL )
\r
81 /* The expected time between each of the timer interrupts - if the jitter was
\r
83 #define timerEXPECTED_DIFFERENCE_VALUE ( ( unsigned short ) ( ( configPERIPHERAL_CLOCK_HZ / 8UL ) / timerINTERRUPT_FREQUENCY ) )
\r
85 /* The highest available interrupt priority. */
\r
86 #define timerHIGHEST_PRIORITY ( 15 )
\r
89 #define timerTIMER_3_COUNT_VALUE ( *( ( unsigned short * ) 0x8801a ) ) /*( CMT3.CMCNT )*/
\r
91 /*-----------------------------------------------------------*/
\r
93 /* Interrupt handler in which the jitter is measured. */
\r
94 __interrupt void vTimer2IntHandler( void );
\r
96 /* Stores the value of the maximum recorded jitter between interrupts. */
\r
97 volatile unsigned short usMaxJitter = 0;
\r
99 /* Counts the number of high frequency interrupts - used to generate the run
\r
101 volatile unsigned long ulHighFrequencyTickCount = 0UL;
\r
103 /*-----------------------------------------------------------*/
\r
105 void vSetupHighFrequencyTimer( void )
\r
107 /* Timer CMT2 is used to generate the interrupts, and CMT3 is used
\r
108 to measure the jitter. */
\r
110 /* Enable compare match timer 2 and 3. */
\r
114 /* Interrupt on compare match. */
\r
115 CMT2.CMCR.BIT.CMIE = 1;
\r
117 /* Set the compare match value. */
\r
118 CMT2.CMCOR = ( unsigned short ) ( ( ( configPERIPHERAL_CLOCK_HZ / timerINTERRUPT_FREQUENCY ) -1 ) / 8 );
\r
120 /* Divide the PCLK by 8. */
\r
121 CMT2.CMCR.BIT.CKS = 0;
\r
122 CMT3.CMCR.BIT.CKS = 0;
\r
124 /* Enable the interrupt... */
\r
125 _IEN( _CMT2_CMI2 ) = 1;
\r
127 /* ...and set its priority to the maximum possible, this is above the priority
\r
128 set by configMAX_SYSCALL_INTERRUPT_PRIORITY so will nest. */
\r
129 _IPR( _CMT2_CMI2 ) = timerHIGHEST_PRIORITY;
\r
131 /* Start the timers. */
\r
132 CMT.CMSTR1.BIT.STR2 = 1;
\r
133 CMT.CMSTR1.BIT.STR3 = 1;
\r
135 /*-----------------------------------------------------------*/
\r
137 #pragma vector = VECT_CMT2_CMI2
\r
138 __interrupt void vTimer2IntHandler( void )
\r
140 volatile unsigned short usCurrentCount;
\r
141 static unsigned short usMaxCount = 0;
\r
142 static unsigned long ulErrorCount = 0UL;
\r
144 /* We use the timer 1 counter value to measure the clock cycles between
\r
145 the timer 0 interrupts. First stop the clock. */
\r
146 CMT.CMSTR1.BIT.STR3 = 0;
\r
149 usCurrentCount = timerTIMER_3_COUNT_VALUE;
\r
151 /* Is this the largest count we have measured yet? */
\r
152 if( usCurrentCount > usMaxCount )
\r
154 if( usCurrentCount > timerEXPECTED_DIFFERENCE_VALUE )
\r
156 usMaxJitter = usCurrentCount - timerEXPECTED_DIFFERENCE_VALUE;
\r
160 /* This should not happen! */
\r
164 usMaxCount = usCurrentCount;
\r
167 /* Used to generate the run time stats. */
\r
168 ulHighFrequencyTickCount++;
\r
170 /* Clear the timer. */
\r
171 timerTIMER_3_COUNT_VALUE = 0;
\r
173 /* Then start the clock again. */
\r
174 CMT.CMSTR1.BIT.STR3 = 1;
\r