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40 the FAQ page "My application does not run, what could be wrong?". Have you
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71 * main-blinky.c is included when the "Blinky" build configuration is used.
72 * main-full.c is included when the "Full" build configuration is used.
74 * main-blinky.c (this file) defines a very simple demo that creates two tasks,
75 * one queue, and one timer. It also demonstrates how Cortex-M3 interrupts can
76 * interact with FreeRTOS tasks/timers.
78 * This simple demo project runs on the SmartFusion A2F-EVAL-KIT evaluation
79 * board, which is populated with an A2F200M3F SmartFusion mixed signal FPGA.
80 * The A2F200M3F incorporates a Cortex-M3 microcontroller.
82 * The idle hook function:
83 * The idle hook function demonstrates how to query the amount of FreeRTOS heap
84 * space that is remaining (see vApplicationIdleHook() defined in this file).
86 * The main() Function:
87 * main() creates one software timer, one queue, and two tasks. It then starts
90 * The Queue Send Task:
91 * The queue send task is implemented by the prvQueueSendTask() function in
92 * this file. prvQueueSendTask() sits in a loop that causes it to repeatedly
93 * block for 200 milliseconds, before sending the value 100 to the queue that
94 * was created within main(). Once the value is sent, the task loops back
95 * around to block for another 200 milliseconds.
97 * The Queue Receive Task:
98 * The queue receive task is implemented by the prvQueueReceiveTask() function
99 * in this file. prvQueueReceiveTask() sits in a loop that causes it to
100 * repeatedly attempt to read data from the queue that was created within
101 * main(). When data is received, the task checks the value of the data, and
102 * if the value equals the expected 100, toggles the green LED. The 'block
103 * time' parameter passed to the queue receive function specifies that the task
104 * should be held in the Blocked state indefinitely to wait for data to be
105 * available on the queue. The queue receive task will only leave the Blocked
106 * state when the queue send task writes to the queue. As the queue send task
107 * writes to the queue every 200 milliseconds, the queue receive task leaves
108 * the Blocked state every 200 milliseconds, and therefore toggles the LED
109 * every 200 milliseconds.
111 * The LED Software Timer and the Button Interrupt:
112 * The user button SW1 is configured to generate an interrupt each time it is
113 * pressed. The interrupt service routine switches an LED on, and resets the
114 * LED software timer. The LED timer has a 5000 millisecond (5 second) period,
115 * and uses a callback function that is defined to just turn the LED off again.
116 * Therefore, pressing the user button will turn the LED on, and the LED will
117 * remain on until a full five seconds pass without the button being pressed.
120 /* Kernel includes. */
121 #include "FreeRTOS.h"
126 /* Microsemi drivers/libraries. */
127 #include "mss_gpio.h"
128 #include "mss_watchdog.h"
131 /* Priorities at which the tasks are created. */
132 #define mainQUEUE_RECEIVE_TASK_PRIORITY ( tskIDLE_PRIORITY + 2 )
133 #define mainQUEUE_SEND_TASK_PRIORITY ( tskIDLE_PRIORITY + 1 )
135 /* The rate at which data is sent to the queue, specified in milliseconds, and
136 converted to ticks using the portTICK_PERIOD_MS constant. */
137 #define mainQUEUE_SEND_FREQUENCY_MS ( 200 / portTICK_PERIOD_MS )
139 /* The number of items the queue can hold. This is 1 as the receive task
140 will remove items as they are added, meaning the send task should always find
142 #define mainQUEUE_LENGTH ( 1 )
144 /* The LED toggle by the queue receive task. */
145 #define mainTASK_CONTROLLED_LED 0x01UL
147 /* The LED turned on by the button interrupt, and turned off by the LED timer. */
148 #define mainTIMER_CONTROLLED_LED 0x02UL
150 /*-----------------------------------------------------------*/
153 * Setup the NVIC, LED outputs, and button inputs.
155 static void prvSetupHardware( void );
158 * The tasks as described in the comments at the top of this file.
160 static void prvQueueReceiveTask( void *pvParameters );
161 static void prvQueueSendTask( void *pvParameters );
164 * The LED timer callback function. This does nothing but switch off the
165 * LED defined by the mainTIMER_CONTROLLED_LED constant.
167 static void vLEDTimerCallback( TimerHandle_t xTimer );
169 /*-----------------------------------------------------------*/
171 /* The queue used by both tasks. */
172 static QueueHandle_t xQueue = NULL;
174 /* The LED software timer. This uses vLEDTimerCallback() as its callback
176 static TimerHandle_t xLEDTimer = NULL;
178 /* Maintains the current LED output state. */
179 static volatile unsigned long ulGPIOState = 0UL;
181 /*-----------------------------------------------------------*/
185 /* Configure the NVIC, LED outputs and button inputs. */
188 /* Create the queue. */
189 xQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( unsigned long ) );
193 /* Start the two tasks as described in the comments at the top of this
195 xTaskCreate( prvQueueReceiveTask, "Rx", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_RECEIVE_TASK_PRIORITY, NULL );
196 xTaskCreate( prvQueueSendTask, "TX", configMINIMAL_STACK_SIZE, NULL, mainQUEUE_SEND_TASK_PRIORITY, NULL );
198 /* Create the software timer that is responsible for turning off the LED
199 if the button is not pushed within 5000ms, as described at the top of
201 xLEDTimer = xTimerCreate( "LEDTimer", /* A text name, purely to help debugging. */
202 ( 5000 / portTICK_PERIOD_MS ),/* The timer period, in this case 5000ms (5s). */
203 pdFALSE, /* This is a one shot timer, so xAutoReload is set to pdFALSE. */
204 ( void * ) 0, /* The ID is not used, so can be set to anything. */
205 vLEDTimerCallback /* The callback function that switches the LED off. */
208 /* Start the tasks and timer running. */
209 vTaskStartScheduler();
212 /* If all is well, the scheduler will now be running, and the following line
213 will never be reached. If the following line does execute, then there was
214 insufficient FreeRTOS heap memory available for the idle and/or timer tasks
215 to be created. See the memory management section on the FreeRTOS web site
219 /*-----------------------------------------------------------*/
221 static void vLEDTimerCallback( TimerHandle_t xTimer )
223 /* The timer has expired - so no button pushes have occurred in the last
224 five seconds - turn the LED off. NOTE - accessing the LED port should use
225 a critical section because it is accessed from multiple tasks, and the
226 button interrupt - in this trivial case, for simplicity, the critical
227 section is omitted. */
228 ulGPIOState |= mainTIMER_CONTROLLED_LED;
229 MSS_GPIO_set_outputs( ulGPIOState );
231 /*-----------------------------------------------------------*/
233 /* The ISR executed when the user button is pushed. */
234 void GPIO8_IRQHandler( void )
236 portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
238 /* The button was pushed, so ensure the LED is on before resetting the
239 LED timer. The LED timer will turn the LED off if the button is not
240 pushed within 5000ms. */
241 ulGPIOState &= ~mainTIMER_CONTROLLED_LED;
242 MSS_GPIO_set_outputs( ulGPIOState );
244 /* This interrupt safe FreeRTOS function can be called from this interrupt
245 because the interrupt priority is below the
246 configMAX_SYSCALL_INTERRUPT_PRIORITY setting in FreeRTOSConfig.h. */
247 xTimerResetFromISR( xLEDTimer, &xHigherPriorityTaskWoken );
249 /* Clear the interrupt before leaving. */
250 MSS_GPIO_clear_irq( MSS_GPIO_8 );
252 /* If calling xTimerResetFromISR() caused a task (in this case the timer
253 service/daemon task) to unblock, and the unblocked task has a priority
254 higher than or equal to the task that was interrupted, then
255 xHigherPriorityTaskWoken will now be set to pdTRUE, and calling
256 portEND_SWITCHING_ISR() will ensure the unblocked task runs next. */
257 portEND_SWITCHING_ISR( xHigherPriorityTaskWoken );
259 /*-----------------------------------------------------------*/
261 static void prvQueueSendTask( void *pvParameters )
263 TickType_t xNextWakeTime;
264 const unsigned long ulValueToSend = 100UL;
266 /* Initialise xNextWakeTime - this only needs to be done once. */
267 xNextWakeTime = xTaskGetTickCount();
271 /* Place this task in the blocked state until it is time to run again.
272 The block time is specified in ticks, the constant used converts ticks
273 to ms. While in the Blocked state this task will not consume any CPU
275 vTaskDelayUntil( &xNextWakeTime, mainQUEUE_SEND_FREQUENCY_MS );
277 /* Send to the queue - causing the queue receive task to unblock and
278 toggle an LED. 0 is used as the block time so the sending operation
279 will not block - it shouldn't need to block as the queue should always
280 be empty at this point in the code. */
281 xQueueSend( xQueue, &ulValueToSend, 0 );
284 /*-----------------------------------------------------------*/
286 static void prvQueueReceiveTask( void *pvParameters )
288 unsigned long ulReceivedValue;
292 /* Wait until something arrives in the queue - this task will block
293 indefinitely provided INCLUDE_vTaskSuspend is set to 1 in
295 xQueueReceive( xQueue, &ulReceivedValue, portMAX_DELAY );
297 /* To get here something must have been received from the queue, but
298 is it the expected value? If it is, toggle the green LED. */
299 if( ulReceivedValue == 100UL )
301 /* NOTE - accessing the LED port should use a critical section
302 because it is accessed from multiple tasks, and the button interrupt
303 - in this trivial case, for simplicity, the critical section is
305 if( ( ulGPIOState & mainTASK_CONTROLLED_LED ) != 0 )
307 ulGPIOState &= ~mainTASK_CONTROLLED_LED;
311 ulGPIOState |= mainTASK_CONTROLLED_LED;
313 MSS_GPIO_set_outputs( ulGPIOState );
317 /*-----------------------------------------------------------*/
319 static void prvSetupHardware( void )
321 SystemCoreClockUpdate();
323 /* Disable the Watch Dog Timer */
326 /* Initialise the GPIO */
329 /* Set up GPIO for the LEDs. */
330 MSS_GPIO_config( MSS_GPIO_0 , MSS_GPIO_OUTPUT_MODE );
331 MSS_GPIO_config( MSS_GPIO_1 , MSS_GPIO_OUTPUT_MODE );
332 MSS_GPIO_config( MSS_GPIO_2 , MSS_GPIO_OUTPUT_MODE );
333 MSS_GPIO_config( MSS_GPIO_3 , MSS_GPIO_OUTPUT_MODE );
334 MSS_GPIO_config( MSS_GPIO_4 , MSS_GPIO_OUTPUT_MODE );
335 MSS_GPIO_config( MSS_GPIO_5 , MSS_GPIO_OUTPUT_MODE );
336 MSS_GPIO_config( MSS_GPIO_6 , MSS_GPIO_OUTPUT_MODE );
337 MSS_GPIO_config( MSS_GPIO_7 , MSS_GPIO_OUTPUT_MODE );
339 /* All LEDs start off. */
340 ulGPIOState = 0xffffffffUL;
341 MSS_GPIO_set_outputs( ulGPIOState );
343 /* Setup the GPIO and the NVIC for the switch used in this simple demo. */
344 NVIC_SetPriority( GPIO8_IRQn, configLIBRARY_MAX_SYSCALL_INTERRUPT_PRIORITY );
345 NVIC_EnableIRQ( GPIO8_IRQn );
346 MSS_GPIO_config( MSS_GPIO_8, MSS_GPIO_INPUT_MODE | MSS_GPIO_IRQ_EDGE_NEGATIVE );
347 MSS_GPIO_enable_irq( MSS_GPIO_8 );
349 /*-----------------------------------------------------------*/
351 void vApplicationMallocFailedHook( void )
353 /* Called if a call to pvPortMalloc() fails because there is insufficient
354 free memory available in the FreeRTOS heap. pvPortMalloc() is called
355 internally by FreeRTOS API functions that create tasks, queues, software
356 timers, and semaphores. The size of the FreeRTOS heap is set by the
357 configTOTAL_HEAP_SIZE configuration constant in FreeRTOSConfig.h. */
360 /*-----------------------------------------------------------*/
362 void vApplicationStackOverflowHook( TaskHandle_t pxTask, char *pcTaskName )
367 /* Run time stack overflow checking is performed if
368 configconfigCHECK_FOR_STACK_OVERFLOW is defined to 1 or 2. This hook
369 function is called if a stack overflow is detected. */
372 /*-----------------------------------------------------------*/
374 void vApplicationIdleHook( void )
376 volatile size_t xFreeHeapSpace;
378 /* This function is called on each cycle of the idle task. In this case it
379 does nothing useful, other than report the amout of FreeRTOS heap that
380 remains unallocated. */
381 xFreeHeapSpace = xPortGetFreeHeapSize();
383 if( xFreeHeapSpace > 100 )
385 /* By now, the kernel has allocated everything it is going to, so
386 if there is a lot of heap remaining unallocated then
387 the value of configTOTAL_HEAP_SIZE in FreeRTOSConfig.h can be
388 reduced accordingly. */
391 /*-----------------------------------------------------------*/
393 void vMainConfigureTimerForRunTimeStats( void )
395 /* This function is not used by the Blinky build configuration, but needs
396 to be defined as the Blinky and Full build configurations share a
397 FreeRTOSConfig.h header file. */
399 /*-----------------------------------------------------------*/
401 unsigned long ulGetRunTimeCounterValue( void )
403 /* This function is not used by the Blinky build configuration, but needs
404 to be defined as the Blinky and Full build configurations share a
405 FreeRTOSConfig.h header file. */