2 FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd.
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4 FEATURES AND PORTS ARE ADDED TO FREERTOS ALL THE TIME. PLEASE VISIT
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5 http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
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7 ***************************************************************************
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9 * FreeRTOS tutorial books are available in pdf and paperback. *
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10 * Complete, revised, and edited pdf reference manuals are also *
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13 * Purchasing FreeRTOS documentation will not only help you, by *
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14 * ensuring you get running as quickly as possible and with an *
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15 * in-depth knowledge of how to use FreeRTOS, it will also help *
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16 * the FreeRTOS project to continue with its mission of providing *
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17 * professional grade, cross platform, de facto standard solutions *
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18 * for microcontrollers - completely free of charge! *
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20 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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22 * Thank you for using FreeRTOS, and thank you for your support! *
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24 ***************************************************************************
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27 This file is part of the FreeRTOS distribution.
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29 FreeRTOS is free software; you can redistribute it and/or modify it under
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30 the terms of the GNU General Public License (version 2) as published by the
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31 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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33 >>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
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34 distribute a combined work that includes FreeRTOS without being obliged to
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35 provide the source code for proprietary components outside of the FreeRTOS
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38 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
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39 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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40 FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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41 details. You should have received a copy of the GNU General Public License
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42 and the FreeRTOS license exception along with FreeRTOS; if not it can be
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43 viewed here: http://www.freertos.org/a00114.html and also obtained by
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44 writing to Real Time Engineers Ltd., contact details for whom are available
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45 on the FreeRTOS WEB site.
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49 ***************************************************************************
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51 * Having a problem? Start by reading the FAQ "My application does *
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52 * not run, what could be wrong?" *
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54 * http://www.FreeRTOS.org/FAQHelp.html *
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56 ***************************************************************************
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59 http://www.FreeRTOS.org - Documentation, books, training, latest versions,
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60 license and Real Time Engineers Ltd. contact details.
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62 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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63 including FreeRTOS+Trace - an indispensable productivity tool, and our new
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64 fully thread aware and reentrant UDP/IP stack.
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66 http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
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67 Integrity Systems, who sell the code with commercial support,
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68 indemnification and middleware, under the OpenRTOS brand.
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70 http://www.SafeRTOS.com - High Integrity Systems also provide a safety
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71 engineered and independently SIL3 certified version for use in safety and
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72 mission critical applications that require provable dependability.
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76 * FreeRTOS-main.c (this file) defines a very simple demo that creates two tasks,
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77 * one queue, and one timer.
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79 * The main() Function:
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80 * main() creates one software timer, one queue, and two tasks. It then starts
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83 * The Queue Send Task:
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84 * The queue send task is implemented by the prvQueueSendTask() function in
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85 * this file. prvQueueSendTask() sits in a loop that causes it to repeatedly
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86 * block for 200 milliseconds, before sending the value 100 to the queue that
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87 * was created within main(). Once the value is sent, the task loops back
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88 * around to block for another 200 milliseconds.
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90 * The Queue Receive Task:
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91 * The queue receive task is implemented by the prvQueueReceiveTask() function
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92 * in this file. prvQueueReceiveTask() sits in a loop that causes it to
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93 * repeatedly attempt to read data from the queue that was created within
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94 * main(). When data is received, the task checks the value of the data, and
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95 * if the value equals the expected 100, increments the ulRecieved variable.
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96 * The 'block time' parameter passed to the queue receive function specifies
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97 * that the task should be held in the Blocked state indefinitely to wait for
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98 * data to be available on the queue. The queue receive task will only leave
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99 * the Blocked state when the queue send task writes to the queue. As the queue
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100 * send task writes to the queue every 200 milliseconds, the queue receive task
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101 * leaves the Blocked state every 200 milliseconds, and therefore toggles the LED
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102 * every 200 milliseconds.
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104 * The Software Timer:
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105 * The software timer is configured to be an "auto reset" timer. Its callback
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106 * function simply increments the ulCallback variable each time it executes.
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109 /* Kernel includes. */
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110 #include "FreeRTOS.h"
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113 #include "timers.h"
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115 /* BSP includes. */
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116 #include "xtmrctr.h"
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118 /* Priorities at which the tasks are created. */
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119 #define mainQUEUE_RECEIVE_TASK_PRIORITY ( tskIDLE_PRIORITY + 2 )
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120 #define mainQUEUE_SEND_TASK_PRIORITY ( tskIDLE_PRIORITY + 1 )
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122 /* The rate at which data is sent to the queue, specified in milliseconds, and
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123 converted to ticks using the portTICK_RATE_MS constant. */
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124 #define mainQUEUE_SEND_FREQUENCY_MS ( 200 / portTICK_RATE_MS )
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126 /* The number of items the queue can hold. This is 1 as the receive task
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127 will remove items as they are added because it has the higher priority, meaning
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128 the send task should always find the queue empty. */
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129 #define mainQUEUE_LENGTH ( 1 )
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131 /* A block time of 0 simply means, "don't block". */
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132 #define mainDONT_BLOCK ( portTickType ) 0
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134 /* The following constants describe the timer instance used in this application.
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135 They are defined here such that a user can easily change all the needed parameters
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137 #define TIMER_DEVICE_ID XPAR_TMRCTR_0_DEVICE_ID
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138 #define TIMER_FREQ_HZ XPAR_TMRCTR_0_CLOCK_FREQ_HZ
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139 #define TIMER_INTR_ID XPAR_INTC_0_TMRCTR_0_VEC_ID
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141 /*-----------------------------------------------------------*/
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144 * The tasks as described in the comments at the top of this file.
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146 static void prvQueueReceiveTask( void *pvParameters );
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147 static void prvQueueSendTask( void *pvParameters );
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150 * The LED timer callback function. This does nothing but increment the
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151 * ulCallback variable each time it executes.
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153 static void vSoftwareTimerCallback( xTimerHandle xTimer );
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155 /*-----------------------------------------------------------*/
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157 /* The queue used by the queue send and queue receive tasks. */
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158 static xQueueHandle xQueue = NULL;
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160 /* The LED software timer. This uses vSoftwareTimerCallback() as its callback
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162 static xTimerHandle xExampleSoftwareTimer = NULL;
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164 /*-----------------------------------------------------------*/
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166 /* Structures that hold the state of the various peripherals used by this demo.
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167 These are used by the Xilinx peripheral driver API functions. */
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168 static XTmrCtr xTimer0Instance;
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170 /* The variable that is incremented each time the receive task receives the
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172 static unsigned long ulReceived = 0UL;
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174 /* The variable that is incremented each time the software time callback function
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176 static unsigned long ulCallback = 0UL;
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178 /*-----------------------------------------------------------*/
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182 /***************************************************************************
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183 See http://www.FreeRTOS.org for full information on FreeRTOS, including
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184 an API reference, pdf API reference manuals, and FreeRTOS tutorial books.
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186 See http://www.freertos.org/Free-RTOS-for-Xilinx-MicroBlaze-on-Spartan-6-FPGA.html
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187 for comprehensive standalone FreeRTOS for MicroBlaze demos.
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188 ***************************************************************************/
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190 /* Create the queue used by the queue send and queue receive tasks as
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191 described in the comments at the top of this file. */
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192 xQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( unsigned long ) );
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194 /* Sanity check that the queue was created. */
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195 configASSERT( xQueue );
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197 /* Start the two tasks as described in the comments at the top of this
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199 xTaskCreate( prvQueueReceiveTask, ( signed char * ) "Rx", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_RECEIVE_TASK_PRIORITY, NULL );
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200 xTaskCreate( prvQueueSendTask, ( signed char * ) "TX", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_SEND_TASK_PRIORITY, NULL );
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202 /* Create the software timer */
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203 xExampleSoftwareTimer = xTimerCreate( ( const signed char * ) "SoftwareTimer", /* A text name, purely to help debugging. */
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204 ( 5000 / portTICK_RATE_MS ), /* The timer period, in this case 5000ms (5s). */
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205 pdTRUE, /* This is an auto-reload timer, so xAutoReload is set to pdTRUE. */
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206 ( void * ) 0, /* The ID is not used, so can be set to anything. */
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207 vSoftwareTimerCallback /* The callback function that switches the LED off. */
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210 /* Start the software timer. */
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211 xTimerStart( xExampleSoftwareTimer, mainDONT_BLOCK );
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213 /* Start the tasks and timer running. */
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214 vTaskStartScheduler();
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216 /* If all is well, the scheduler will now be running, and the following line
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217 will never be reached. If the following line does execute, then there was
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218 insufficient FreeRTOS heap memory available for the idle and/or timer tasks
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219 to be created. See the memory management section on the FreeRTOS web site
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220 for more details. */
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223 /*-----------------------------------------------------------*/
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225 /* The callback is executed when the software timer expires. */
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226 static void vSoftwareTimerCallback( xTimerHandle xTimer )
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228 /* Just increment the ulCallbac variable. */
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231 /*-----------------------------------------------------------*/
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233 static void prvQueueSendTask( void *pvParameters )
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235 portTickType xNextWakeTime;
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236 const unsigned long ulValueToSend = 100UL;
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238 /* Initialise xNextWakeTime - this only needs to be done once. */
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239 xNextWakeTime = xTaskGetTickCount();
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243 /* Place this task in the blocked state until it is time to run again.
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244 The block time is specified in ticks, the constant used converts ticks
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245 to ms. While in the Blocked state this task will not consume any CPU
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247 vTaskDelayUntil( &xNextWakeTime, mainQUEUE_SEND_FREQUENCY_MS );
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249 /* Send to the queue - causing the queue receive task to unblock and
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250 toggle an LED. 0 is used as the block time so the sending operation
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251 will not block - it shouldn't need to block as the queue should always
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252 be empty at this point in the code. */
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253 xQueueSend( xQueue, &ulValueToSend, mainDONT_BLOCK );
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256 /*-----------------------------------------------------------*/
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258 static void prvQueueReceiveTask( void *pvParameters )
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260 unsigned long ulReceivedValue;
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264 /* Wait until something arrives in the queue - this task will block
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265 indefinitely provided INCLUDE_vTaskSuspend is set to 1 in
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266 FreeRTOSConfig.h. */
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267 xQueueReceive( xQueue, &ulReceivedValue, portMAX_DELAY );
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269 /* To get here something must have been received from the queue, but
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270 is it the expected value? If it is, increment the ulReceived variable. */
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271 if( ulReceivedValue == 100UL )
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277 /*-----------------------------------------------------------*/
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279 void vApplicationMallocFailedHook( void )
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281 /* vApplicationMallocFailedHook() will only be called if
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282 configUSE_MALLOC_FAILED_HOOK is set to 1 in FreeRTOSConfig.h. It is a hook
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283 function that will get called if a call to pvPortMalloc() fails.
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284 pvPortMalloc() is called internally by the kernel whenever a task, queue or
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285 semaphore is created. It is also called by various parts of the demo
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286 application. If heap_1.c or heap_2.c are used, then the size of the heap
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287 available to pvPortMalloc() is defined by configTOTAL_HEAP_SIZE in
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288 FreeRTOSConfig.h, and the xPortGetFreeHeapSize() API function can be used
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289 to query the size of free heap space that remains (although it does not
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290 provide information on how the remaining heap might be fragmented). */
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291 taskDISABLE_INTERRUPTS();
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294 /*-----------------------------------------------------------*/
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296 void vApplicationStackOverflowHook( xTaskHandle *pxTask, signed char *pcTaskName )
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298 ( void ) pcTaskName;
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301 /* vApplicationStackOverflowHook() will only be called if
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302 configCHECK_FOR_STACK_OVERFLOW is set to either 1 or 2. The handle and name
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303 of the offending task will be passed into the hook function via its
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304 parameters. However, when a stack has overflowed, it is possible that the
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305 parameters will have been corrupted, in which case the pxCurrentTCB variable
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306 can be inspected directly. */
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307 taskDISABLE_INTERRUPTS();
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310 /*-----------------------------------------------------------*/
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312 void vApplicationIdleHook( void )
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314 /* vApplicationIdleHook() will only be called if configUSE_IDLE_HOOK is set
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315 to 1 in FreeRTOSConfig.h. It will be called on each iteration of the idle
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316 task. It is essential that code added to this hook function never attempts
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317 to block in any way (for example, call xQueueReceive() with a block time
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318 specified, or call vTaskDelay()). If the application makes use of the
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319 vTaskDelete() API function (as this demo application does) then it is also
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320 important that vApplicationIdleHook() is permitted to return to its calling
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321 function, because it is the responsibility of the idle task to clean up
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322 memory allocated by the kernel to any task that has since been deleted. */
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324 /*-----------------------------------------------------------*/
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326 void vApplicationTickHook( void )
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328 /* vApplicationTickHook() will only be called if configUSE_TICK_HOOK is set
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329 to 1 in FreeRTOSConfig.h. It executes from an interrupt context so must
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330 not use any FreeRTOS API functions that do not end in ...FromISR().
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332 This simple blinky demo does not use the tick hook, but a tick hook is
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333 required to be defined as the blinky and full demos share a
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334 FreeRTOSConfig.h header file. */
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336 /*-----------------------------------------------------------*/
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338 /* This is an application defined callback function used to install the tick
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339 interrupt handler. It is provided as an application callback because the kernel
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340 will run on lots of different MicroBlaze and FPGA configurations - there could
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341 be multiple timer instances in the hardware platform and the users can chose to
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342 use any one of them. This example uses Timer 0. If that is available in your
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343 hardware platform then this example callback implementation should not require
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344 modification. The definitions for the timer instance used are at the top of this
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345 file so that users can change them at one place based on the timer instance they
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346 use. The name of the interrupt handler that should be installed is vPortTickISR(),
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347 which the function below declares as an extern. */
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348 void vApplicationSetupTimerInterrupt( void )
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350 portBASE_TYPE xStatus;
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351 const unsigned char ucTimerCounterNumber = ( unsigned char ) 0U;
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352 const unsigned long ulCounterValue = ( ( TIMER_FREQ_HZ / configTICK_RATE_HZ ) - 1UL );
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353 extern void vPortTickISR( void *pvUnused );
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355 /* Initialise the timer/counter. */
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356 xStatus = XTmrCtr_Initialize( &xTimer0Instance, TIMER_DEVICE_ID );
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358 if( xStatus == XST_SUCCESS )
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360 /* Install the tick interrupt handler as the timer ISR.
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361 *NOTE* The xPortInstallInterruptHandler() API function must be used for
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363 xStatus = xPortInstallInterruptHandler( TIMER_INTR_ID, vPortTickISR, NULL );
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366 if( xStatus == pdPASS )
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368 /* Enable the timer interrupt in the interrupt controller.
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369 *NOTE* The vPortEnableInterrupt() API function must be used for this
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371 vPortEnableInterrupt( TIMER_INTR_ID );
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373 /* Configure the timer interrupt handler. */
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374 XTmrCtr_SetHandler( &xTimer0Instance, ( void * ) vPortTickISR, NULL );
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376 /* Set the correct period for the timer. */
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377 XTmrCtr_SetResetValue( &xTimer0Instance, ucTimerCounterNumber, ulCounterValue );
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379 /* Enable the interrupts. Auto-reload mode is used to generate a
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380 periodic tick. Note that interrupts are disabled when this function is
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381 called, so interrupts will not start to be processed until the first
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382 task has started to run. */
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383 XTmrCtr_SetOptions( &xTimer0Instance, ucTimerCounterNumber, ( XTC_INT_MODE_OPTION | XTC_AUTO_RELOAD_OPTION | XTC_DOWN_COUNT_OPTION ) );
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385 /* Start the timer. */
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386 XTmrCtr_Start( &xTimer0Instance, ucTimerCounterNumber );
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389 /* Sanity check that the function executed as expected. */
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390 configASSERT( ( xStatus == pdPASS ) );
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392 /*-----------------------------------------------------------*/
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394 /* This is an application defined callback function used to clear whichever
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395 interrupt was installed by the the vApplicationSetupTimerInterrupt() callback
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396 function - in this case the interrupt generated by the AXI timer. It is
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397 provided as an application callback because the kernel will run on lots of
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398 different MicroBlaze and FPGA configurations - not all of which will have the
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399 same timer peripherals defined or available. This example uses the AXI Timer 0.
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400 If that is available on your hardware platform then this example callback
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401 implementation should not require modification provided the example definition
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402 of vApplicationSetupTimerInterrupt() is also not modified. */
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403 void vApplicationClearTimerInterrupt( void )
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405 unsigned long ulCSR;
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407 /* Clear the timer interrupt */
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408 ulCSR = XTmrCtr_GetControlStatusReg( XPAR_TMRCTR_0_BASEADDR, 0 );
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409 XTmrCtr_SetControlStatusReg( XPAR_TMRCTR_0_BASEADDR, 0, ulCSR );
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411 /*-----------------------------------------------------------*/
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