2 FreeRTOS V7.1.1 - Copyright (C) 2012 Real Time Engineers Ltd.
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5 ***************************************************************************
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7 * FreeRTOS tutorial books are available in pdf and paperback. *
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8 * Complete, revised, and edited pdf reference manuals are also *
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11 * Purchasing FreeRTOS documentation will not only help you, by *
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12 * ensuring you get running as quickly as possible and with an *
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13 * in-depth knowledge of how to use FreeRTOS, it will also help *
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14 * the FreeRTOS project to continue with its mission of providing *
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15 * professional grade, cross platform, de facto standard solutions *
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16 * for microcontrollers - completely free of charge! *
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18 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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20 * Thank you for using FreeRTOS, and thank you for your support! *
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22 ***************************************************************************
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25 This file is part of the FreeRTOS distribution.
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27 FreeRTOS is free software; you can redistribute it and/or modify it under
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28 the terms of the GNU General Public License (version 2) as published by the
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29 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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30 >>>NOTE<<< The modification to the GPL is included to allow you to
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31 distribute a combined work that includes FreeRTOS without being obliged to
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32 provide the source code for proprietary components outside of the FreeRTOS
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33 kernel. FreeRTOS is distributed in the hope that it will be useful, but
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34 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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35 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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36 more details. You should have received a copy of the GNU General Public
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37 License and the FreeRTOS license exception along with FreeRTOS; if not it
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38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
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39 by writing to Richard Barry, contact details for whom are available on the
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44 ***************************************************************************
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46 * Having a problem? Start by reading the FAQ "My application does *
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47 * not run, what could be wrong? *
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49 * http://www.FreeRTOS.org/FAQHelp.html *
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51 ***************************************************************************
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54 http://www.FreeRTOS.org - Documentation, training, latest information,
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55 license and contact details.
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57 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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58 including FreeRTOS+Trace - an indispensable productivity tool.
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60 Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
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61 the code with commercial support, indemnification, and middleware, under
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62 the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
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63 provide a safety engineered and independently SIL3 certified version under
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64 the SafeRTOS brand: http://www.SafeRTOS.com.
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68 * main-blinky.c is included when the "Blinky" build configuration is used.
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69 * main-full.c is included when the "Full" build configuration is used.
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71 * main-blinky.c (this file) defines a very simple demo that creates two tasks,
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72 * one queue, and one timer. It also demonstrates how Cortex-M3 interrupts can
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73 * interact with FreeRTOS tasks/timers.
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75 * This simple demo project runs on the SmartFusion A2F-EVAL-KIT evaluation
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76 * board, which is populated with an A2F200M3F SmartFusion mixed signal FPGA.
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77 * The A2F200M3F incorporates a Cortex-M3 microcontroller.
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79 * The idle hook function:
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80 * The idle hook function demonstrates how to query the amount of FreeRTOS heap
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81 * space that is remaining (see vApplicationIdleHook() defined in this file).
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83 * The main() Function:
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84 * main() creates one software timer, one queue, and two tasks. It then starts
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87 * The Queue Send Task:
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88 * The queue send task is implemented by the prvQueueSendTask() function in
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89 * this file. prvQueueSendTask() sits in a loop that causes it to repeatedly
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90 * block for 200 milliseconds, before sending the value 100 to the queue that
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91 * was created within main(). Once the value is sent, the task loops back
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92 * around to block for another 200 milliseconds.
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94 * The Queue Receive Task:
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95 * The queue receive task is implemented by the prvQueueReceiveTask() function
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96 * in this file. prvQueueReceiveTask() sits in a loop that causes it to
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97 * repeatedly attempt to read data from the queue that was created within
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98 * main(). When data is received, the task checks the value of the data, and
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99 * if the value equals the expected 100, toggles the green LED. The 'block
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100 * time' parameter passed to the queue receive function specifies that the task
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101 * should be held in the Blocked state indefinitely to wait for data to be
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102 * available on the queue. The queue receive task will only leave the Blocked
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103 * state when the queue send task writes to the queue. As the queue send task
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104 * writes to the queue every 200 milliseconds, the queue receive task leaves
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105 * the Blocked state every 200 milliseconds, and therefore toggles the LED
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106 * every 200 milliseconds.
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108 * The LED Software Timer and the Button Interrupt:
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109 * The user button SW1 is configured to generate an interrupt each time it is
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110 * pressed. The interrupt service routine switches an LED on, and resets the
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111 * LED software timer. The LED timer has a 5000 millisecond (5 second) period,
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112 * and uses a callback function that is defined to just turn the LED off again.
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113 * Therefore, pressing the user button will turn the LED on, and the LED will
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114 * remain on until a full five seconds pass without the button being pressed.
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117 /* Kernel includes. */
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118 #include "FreeRTOS.h"
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121 #include "timers.h"
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123 /* Microsemi drivers/libraries. */
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124 #include "mss_gpio.h"
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125 #include "mss_watchdog.h"
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128 /* Priorities at which the tasks are created. */
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129 #define mainQUEUE_RECEIVE_TASK_PRIORITY ( tskIDLE_PRIORITY + 2 )
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130 #define mainQUEUE_SEND_TASK_PRIORITY ( tskIDLE_PRIORITY + 1 )
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132 /* The rate at which data is sent to the queue, specified in milliseconds, and
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133 converted to ticks using the portTICK_RATE_MS constant. */
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134 #define mainQUEUE_SEND_FREQUENCY_MS ( 200 / portTICK_RATE_MS )
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136 /* The number of items the queue can hold. This is 1 as the receive task
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137 will remove items as they are added, meaning the send task should always find
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138 the queue empty. */
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139 #define mainQUEUE_LENGTH ( 1 )
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141 /* The LED toggle by the queue receive task. */
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142 #define mainTASK_CONTROLLED_LED 0x01UL
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144 /* The LED turned on by the button interrupt, and turned off by the LED timer. */
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145 #define mainTIMER_CONTROLLED_LED 0x02UL
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147 /*-----------------------------------------------------------*/
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150 * Setup the NVIC, LED outputs, and button inputs.
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152 static void prvSetupHardware( void );
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155 * The tasks as described in the comments at the top of this file.
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157 static void prvQueueReceiveTask( void *pvParameters );
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158 static void prvQueueSendTask( void *pvParameters );
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161 * The LED timer callback function. This does nothing but switch off the
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162 * LED defined by the mainTIMER_CONTROLLED_LED constant.
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164 static void vLEDTimerCallback( xTimerHandle xTimer );
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166 /*-----------------------------------------------------------*/
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168 /* The queue used by both tasks. */
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169 static xQueueHandle xQueue = NULL;
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171 /* The LED software timer. This uses vLEDTimerCallback() as its callback
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173 static xTimerHandle xLEDTimer = NULL;
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175 /* Maintains the current LED output state. */
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176 static volatile unsigned long ulGPIOState = 0UL;
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178 /*-----------------------------------------------------------*/
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182 /* Configure the NVIC, LED outputs and button inputs. */
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183 prvSetupHardware();
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185 /* Create the queue. */
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186 xQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( unsigned long ) );
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188 if( xQueue != NULL )
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190 /* Start the two tasks as described in the comments at the top of this
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192 xTaskCreate( prvQueueReceiveTask, ( signed char * ) "Rx", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_RECEIVE_TASK_PRIORITY, NULL );
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193 xTaskCreate( prvQueueSendTask, ( signed char * ) "TX", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_SEND_TASK_PRIORITY, NULL );
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195 /* Create the software timer that is responsible for turning off the LED
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196 if the button is not pushed within 5000ms, as described at the top of
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198 xLEDTimer = xTimerCreate( ( const signed char * ) "LEDTimer", /* A text name, purely to help debugging. */
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199 ( 5000 / portTICK_RATE_MS ), /* The timer period, in this case 5000ms (5s). */
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200 pdFALSE, /* This is a one shot timer, so xAutoReload is set to pdFALSE. */
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201 ( void * ) 0, /* The ID is not used, so can be set to anything. */
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202 vLEDTimerCallback /* The callback function that switches the LED off. */
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205 /* Start the tasks and timer running. */
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206 vTaskStartScheduler();
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209 /* If all is well, the scheduler will now be running, and the following line
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210 will never be reached. If the following line does execute, then there was
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211 insufficient FreeRTOS heap memory available for the idle and/or timer tasks
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212 to be created. See the memory management section on the FreeRTOS web site
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213 for more details. */
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216 /*-----------------------------------------------------------*/
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218 static void vLEDTimerCallback( xTimerHandle xTimer )
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220 /* The timer has expired - so no button pushes have occurred in the last
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221 five seconds - turn the LED off. NOTE - accessing the LED port should use
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222 a critical section because it is accessed from multiple tasks, and the
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223 button interrupt - in this trivial case, for simplicity, the critical
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224 section is omitted. */
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225 ulGPIOState |= mainTIMER_CONTROLLED_LED;
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226 MSS_GPIO_set_outputs( ulGPIOState );
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228 /*-----------------------------------------------------------*/
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230 /* The ISR executed when the user button is pushed. */
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231 void GPIO8_IRQHandler( void )
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233 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
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235 /* The button was pushed, so ensure the LED is on before resetting the
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236 LED timer. The LED timer will turn the LED off if the button is not
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237 pushed within 5000ms. */
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238 ulGPIOState &= ~mainTIMER_CONTROLLED_LED;
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239 MSS_GPIO_set_outputs( ulGPIOState );
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241 /* This interrupt safe FreeRTOS function can be called from this interrupt
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242 because the interrupt priority is below the
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243 configMAX_SYSCALL_INTERRUPT_PRIORITY setting in FreeRTOSConfig.h. */
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244 xTimerResetFromISR( xLEDTimer, &xHigherPriorityTaskWoken );
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246 /* Clear the interrupt before leaving. */
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247 MSS_GPIO_clear_irq( MSS_GPIO_8 );
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249 /* If calling xTimerResetFromISR() caused a task (in this case the timer
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250 service/daemon task) to unblock, and the unblocked task has a priority
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251 higher than or equal to the task that was interrupted, then
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252 xHigherPriorityTaskWoken will now be set to pdTRUE, and calling
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253 portEND_SWITCHING_ISR() will ensure the unblocked task runs next. */
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254 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
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256 /*-----------------------------------------------------------*/
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258 static void prvQueueSendTask( void *pvParameters )
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260 portTickType xNextWakeTime;
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261 const unsigned long ulValueToSend = 100UL;
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263 /* Initialise xNextWakeTime - this only needs to be done once. */
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264 xNextWakeTime = xTaskGetTickCount();
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268 /* Place this task in the blocked state until it is time to run again.
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269 The block time is specified in ticks, the constant used converts ticks
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270 to ms. While in the Blocked state this task will not consume any CPU
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272 vTaskDelayUntil( &xNextWakeTime, mainQUEUE_SEND_FREQUENCY_MS );
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274 /* Send to the queue - causing the queue receive task to unblock and
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275 toggle an LED. 0 is used as the block time so the sending operation
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276 will not block - it shouldn't need to block as the queue should always
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277 be empty at this point in the code. */
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278 xQueueSend( xQueue, &ulValueToSend, 0 );
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281 /*-----------------------------------------------------------*/
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283 static void prvQueueReceiveTask( void *pvParameters )
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285 unsigned long ulReceivedValue;
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289 /* Wait until something arrives in the queue - this task will block
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290 indefinitely provided INCLUDE_vTaskSuspend is set to 1 in
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291 FreeRTOSConfig.h. */
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292 xQueueReceive( xQueue, &ulReceivedValue, portMAX_DELAY );
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294 /* To get here something must have been received from the queue, but
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295 is it the expected value? If it is, toggle the green LED. */
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296 if( ulReceivedValue == 100UL )
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298 /* NOTE - accessing the LED port should use a critical section
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299 because it is accessed from multiple tasks, and the button interrupt
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300 - in this trivial case, for simplicity, the critical section is
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302 if( ( ulGPIOState & mainTASK_CONTROLLED_LED ) != 0 )
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304 ulGPIOState &= ~mainTASK_CONTROLLED_LED;
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308 ulGPIOState |= mainTASK_CONTROLLED_LED;
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310 MSS_GPIO_set_outputs( ulGPIOState );
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314 /*-----------------------------------------------------------*/
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316 static void prvSetupHardware( void )
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318 SystemCoreClockUpdate();
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320 /* Disable the Watch Dog Timer */
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323 /* Initialise the GPIO */
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326 /* Set up GPIO for the LEDs. */
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327 MSS_GPIO_config( MSS_GPIO_0 , MSS_GPIO_OUTPUT_MODE );
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328 MSS_GPIO_config( MSS_GPIO_1 , MSS_GPIO_OUTPUT_MODE );
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329 MSS_GPIO_config( MSS_GPIO_2 , MSS_GPIO_OUTPUT_MODE );
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330 MSS_GPIO_config( MSS_GPIO_3 , MSS_GPIO_OUTPUT_MODE );
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331 MSS_GPIO_config( MSS_GPIO_4 , MSS_GPIO_OUTPUT_MODE );
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332 MSS_GPIO_config( MSS_GPIO_5 , MSS_GPIO_OUTPUT_MODE );
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333 MSS_GPIO_config( MSS_GPIO_6 , MSS_GPIO_OUTPUT_MODE );
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334 MSS_GPIO_config( MSS_GPIO_7 , MSS_GPIO_OUTPUT_MODE );
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336 /* All LEDs start off. */
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337 ulGPIOState = 0xffffffffUL;
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338 MSS_GPIO_set_outputs( ulGPIOState );
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340 /* Setup the GPIO and the NVIC for the switch used in this simple demo. */
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341 NVIC_SetPriority( GPIO8_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
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342 NVIC_EnableIRQ( GPIO8_IRQn );
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343 MSS_GPIO_config( MSS_GPIO_8, MSS_GPIO_INPUT_MODE | MSS_GPIO_IRQ_EDGE_NEGATIVE );
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344 MSS_GPIO_enable_irq( MSS_GPIO_8 );
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346 /*-----------------------------------------------------------*/
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348 void vApplicationMallocFailedHook( void )
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350 /* Called if a call to pvPortMalloc() fails because there is insufficient
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351 free memory available in the FreeRTOS heap. pvPortMalloc() is called
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352 internally by FreeRTOS API functions that create tasks, queues, software
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353 timers, and semaphores. The size of the FreeRTOS heap is set by the
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354 configTOTAL_HEAP_SIZE configuration constant in FreeRTOSConfig.h. */
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357 /*-----------------------------------------------------------*/
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359 void vApplicationStackOverflowHook( xTaskHandle pxTask, signed char *pcTaskName )
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361 ( void ) pcTaskName;
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364 /* Run time stack overflow checking is performed if
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365 configconfigCHECK_FOR_STACK_OVERFLOW is defined to 1 or 2. This hook
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366 function is called if a stack overflow is detected. */
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369 /*-----------------------------------------------------------*/
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371 void vApplicationIdleHook( void )
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373 volatile size_t xFreeHeapSpace;
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375 /* This function is called on each cycle of the idle task. In this case it
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376 does nothing useful, other than report the amout of FreeRTOS heap that
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377 remains unallocated. */
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378 xFreeHeapSpace = xPortGetFreeHeapSize();
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380 if( xFreeHeapSpace > 100 )
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382 /* By now, the kernel has allocated everything it is going to, so
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383 if there is a lot of heap remaining unallocated then
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384 the value of configTOTAL_HEAP_SIZE in FreeRTOSConfig.h can be
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385 reduced accordingly. */
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388 /*-----------------------------------------------------------*/
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390 void vMainConfigureTimerForRunTimeStats( void )
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392 /* This function is not used by the Blinky build configuration, but needs
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393 to be defined as the Blinky and Full build configurations share a
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394 FreeRTOSConfig.h header file. */
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396 /*-----------------------------------------------------------*/
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398 unsigned long ulGetRunTimeCounterValue( void )
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400 /* This function is not used by the Blinky build configuration, but needs
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401 to be defined as the Blinky and Full build configurations share a
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402 FreeRTOSConfig.h header file. */
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