2 FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 Richard Barry.
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4 This file is part of the FreeRTOS.org distribution.
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6 FreeRTOS.org is free software; you can redistribute it and/or modify
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7 it under the terms of the GNU General Public License as published by
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8 the Free Software Foundation; either version 2 of the License, or
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9 (at your option) any later version.
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11 FreeRTOS.org is distributed in the hope that it will be useful,
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12 but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 GNU General Public License for more details.
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16 You should have received a copy of the GNU General Public License
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17 along with FreeRTOS.org; if not, write to the Free Software
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18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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20 A special exception to the GPL can be applied should you wish to distribute
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21 a combined work that includes FreeRTOS.org, without being obliged to provide
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22 the source code for any proprietary components. See the licensing section
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23 of http://www.FreeRTOS.org for full details of how and when the exception
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26 ***************************************************************************
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27 ***************************************************************************
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29 * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation *
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31 * This is a concise, step by step, 'hands on' guide that describes both *
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32 * general multitasking concepts and FreeRTOS specifics. It presents and *
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33 * explains numerous examples that are written using the FreeRTOS API. *
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34 * Full source code for all the examples is provided in an accompanying *
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37 ***************************************************************************
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38 ***************************************************************************
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40 Please ensure to read the configuration and relevant port sections of the
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41 online documentation.
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43 http://www.FreeRTOS.org - Documentation, latest information, license and
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46 http://www.SafeRTOS.com - A version that is certified for use in safety
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49 http://www.OpenRTOS.com - Commercial support, development, porting,
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50 licensing and training services.
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54 * Instead of the normal single demo application, the PIC18F demo is split
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55 * into several smaller programs of which this is the second. This enables the
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56 * demo's to be executed on the RAM limited 40 pin devices. The 64 and 80 pin
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57 * devices require a more costly development platform and are not so readily
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60 * The RTOSDemo2 project is configured for a PIC18F452 device. Main2.c starts
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61 * 5 tasks (including the idle task).
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63 * The first, second and third tasks do nothing but flash an LED. This gives
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64 * visual feedback that everything is executing as expected. One task flashes
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65 * an LED every 333ms (i.e. on and off every 333/2 ms), then next every 666ms
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66 * and the last every 999ms.
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68 * The last task runs at the idle priority. It repeatedly performs a 32bit
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69 * calculation and checks it's result against the expected value. This checks
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70 * that the temporary storage utilised by the compiler to hold intermediate
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71 * results does not get corrupted when the task gets switched in and out.
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72 * should the calculation ever provide an incorrect result the final LED is
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75 * On entry to main() an 'X' is transmitted. Monitoring the serial port using a
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76 * dumb terminal allows for verification that the device is not continuously
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77 * being reset (no more than one 'X' should be transmitted).
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79 * http://www.FreeRTOS.org contains important information on the use of the
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86 + Delay periods are now specified using variables and constants of
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87 portTickType rather than unsigned portLONG.
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90 /* Scheduler include files. */
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91 #include "FreeRTOS.h"
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94 /* Demo app include files. */
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96 #include "partest.h"
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99 /* Priority definitions for the LED tasks. Other tasks just use the idle
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101 #define mainLED_FLASH_PRIORITY ( tskIDLE_PRIORITY + ( unsigned portBASE_TYPE ) 1 )
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103 /* The LED that is lit when should the calculation fail. */
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104 #define mainCHECK_TASK_LED ( ( unsigned portBASE_TYPE ) 3 )
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106 /* Constants required for the communications. Only one character is ever
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108 #define mainCOMMS_QUEUE_LENGTH ( ( unsigned portBASE_TYPE ) 5 )
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109 #define mainNO_BLOCK ( ( portTickType ) 0 )
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110 #define mainBAUD_RATE ( ( unsigned portLONG ) 9600 )
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113 * The task that performs the 32 bit calculation at the idle priority.
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115 static void vCalculationTask( void *pvParameters );
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117 /*-----------------------------------------------------------*/
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119 /* Creates the tasks, then starts the scheduler. */
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122 /* Initialise the required hardware. */
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123 vParTestInitialise();
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124 vPortInitialiseBlocks();
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126 /* Send a character so we have some visible feedback of a reset. */
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127 xSerialPortInitMinimal( mainBAUD_RATE, mainCOMMS_QUEUE_LENGTH );
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128 xSerialPutChar( NULL, 'X', mainNO_BLOCK );
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130 /* Start the standard LED flash tasks as defined in demo/common/minimal. */
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131 vStartLEDFlashTasks( mainLED_FLASH_PRIORITY );
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133 /* Start the check task defined in this file. */
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134 xTaskCreate( vCalculationTask, ( const portCHAR * const ) "Check", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, NULL );
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136 /* Start the scheduler. */
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137 vTaskStartScheduler();
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139 /*-----------------------------------------------------------*/
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141 static void vCalculationTask( void *pvParameters )
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143 volatile unsigned long ulCalculatedValue; /* Volatile to ensure optimisation is minimal. */
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145 /* Continuously perform a calculation. If the calculation result is ever
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146 incorrect turn the LED on. */
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149 /* A good optimising compiler would just remove all this! */
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150 ulCalculatedValue = 1234UL;
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151 ulCalculatedValue *= 99UL;
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153 if( ulCalculatedValue != 122166UL )
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155 vParTestSetLED( mainCHECK_TASK_LED, pdTRUE );
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158 ulCalculatedValue *= 9876UL;
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160 if( ulCalculatedValue != 1206511416UL )
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162 vParTestSetLED( mainCHECK_TASK_LED, pdTRUE );
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165 ulCalculatedValue /= 15UL;
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167 if( ulCalculatedValue != 80434094UL )
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169 vParTestSetLED( mainCHECK_TASK_LED, pdTRUE );
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172 ulCalculatedValue += 918273UL;
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174 if( ulCalculatedValue != 81352367UL )
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176 vParTestSetLED( mainCHECK_TASK_LED, pdTRUE );
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180 /*-----------------------------------------------------------*/
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