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FreeRTOS V7.4.1 - Copyright (C) 2013 Real Time Engineers Ltd.
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This file is part of the FreeRTOS distribution.
FreeRTOS is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License (version 2) as published by the
Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
>>>>>>NOTE<<<<<< The modification to the GPL is included to allow you to
distribute a combined work that includes FreeRTOS without being obliged to
provide the source code for proprietary components outside of the FreeRTOS
FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
details. You should have received a copy of the GNU General Public License
and the FreeRTOS license exception along with FreeRTOS; if not it can be
viewed here: and also obtained by
writing to Real Time Engineers Ltd., contact details for whom are available
on the FreeRTOS WEB site.
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* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong?" *
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*************************************************************************** - Documentation, books, training, latest versions,
license and Real Time Engineers Ltd. contact details. - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool, and our new
fully thread aware and reentrant UDP/IP stack. - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems, who sell the code with commercial support,
indemnification and middleware, under the OpenRTOS brand. - High Integrity Systems also provide a safety
engineered and independently SIL3 certified version for use in safety and
mission critical applications that require provable dependability.
* This is a very simple demo that creates two tasks and one queue. One task
* (the queue receive task) blocks on the queue to wait for data to arrive,
* toggling an LED each time '100' is received. The other task (the queue send
* task) repeatedly blocks for a fixed period before sending '100' to the queue
* (causing the first task to toggle the LED).
* For a much more complete and complex example select either the Debug or
* Debug_with_optimisation build configurations within the HEW IDE.
/* Hardware specific includes. */
#include "iodefine.h"
/* Kernel includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
/* Priorities at which the tasks are created. */
/* The rate at which data is sent to the queue, specified in milliseconds. */
#define mainQUEUE_SEND_FREQUENCY_MS ( 500 / portTICK_RATE_MS )
/* The number of items the queue can hold. This is 1 as the receive task
will remove items as they are added so the send task should always find the
queue empty. */
#define mainQUEUE_LENGTH ( 1 )
* The tasks as defined at the top of this file.
static void prvQueueReceiveTask( void *pvParameters );
static void prvQueueSendTask( void *pvParameters );
/* The queue used by both tasks. */
static xQueueHandle xQueue = NULL;
/* This variable is not used by this simple Blinky example. It is defined
purely to allow the project to link as it is used by the full build
configuration. */
volatile unsigned long ulHighFrequencyTickCount = 0UL;
void main(void)
extern void HardwareSetup( void );
/* Renesas provided CPU configuration routine. The clocks are configured in
here. */
/* Turn all LEDs off. */
/* Create the queue. */
xQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( unsigned long ) );
if( xQueue != NULL )
/* Start the two tasks as described at the top of this file. */
xTaskCreate( prvQueueReceiveTask, "Rx", configMINIMAL_STACK_SIZE, NULL, configQUEUE_RECEIVE_TASK_PRIORITY, NULL );
xTaskCreate( prvQueueSendTask, "TX", configMINIMAL_STACK_SIZE, NULL, configQUEUE_SEND_TASK_PRIORITY, NULL );
/* Start the tasks running. */
/* If all is well the next line of code will not be reached as the scheduler
will be running. If the next line is reached then it is likely that there was
insufficient heap available for the idle task to be created. */
for( ;; );
static void prvQueueSendTask( void *pvParameters )
portTickType xNextWakeTime;
const unsigned long ulValueToSend = 100UL;
/* Initialise xNextWakeTime - this only needs to be done once. */
xNextWakeTime = xTaskGetTickCount();
for( ;; )
/* Place this task in the blocked state until it is time to run again.
The block state is specified in ticks, the constant used converts ticks
to ms. */
vTaskDelayUntil( &xNextWakeTime, mainQUEUE_SEND_FREQUENCY_MS );
/* Send to the queue - causing the queue receive task to flash its LED. 0
is used so the send does not block - it shouldn't need to as the queue
should always be empty here (it should always be empty because the task
removing items from the queue has a higher priority than the task adding
things to the queue). */
xQueueSend( xQueue, &ulValueToSend, 0UL );
static void prvQueueReceiveTask( void *pvParameters )
unsigned long ulReceivedValue;
for( ;; )
/* Wait until something arives in the queue - this will block
indefinitely provided INCLUDE_vTaskSuspend is set to 1 in
FreeRTOSConfig.h. */
xQueueReceive( xQueue, &ulReceivedValue, portMAX_DELAY );
/* To get here something must have arrived, but is it the expected
value? If it is, toggle the LED. */
if( ulReceivedValue == 100UL )
vParTestToggleLED( 0 );
/* A callback function named vApplicationSetupTimerInterrupt() must be defined
to configure a tick interrupt source, and configTICK_VECTOR set in
FreeRTOSConfig.h to install the tick interrupt handler in the correct position
in the vector table. This example uses a compare match timer. It can be
into any FreeRTOS project, provided the same compare match timer is available. */
void vApplicationSetupTimerInterrupt( void )
/* Enable compare match timer 0. */
MSTP( CMT0 ) = 0;
/* Interrupt on compare match. */
/* Set the compare match value. */
CMT0.CMCOR = ( unsigned short ) ( ( ( configPERIPHERAL_CLOCK_HZ / configTICK_RATE_HZ ) -1 ) / 8 );
/* Divide the PCLK by 8. */
/* Enable the interrupt... */
_IEN( _CMT0_CMI0 ) = 1;
/* ...and set its priority to the application defined kernel priority. */
/* Start the timer. */
/* If configUSE_MALLOC_FAILED_HOOK is set to 1 in FreeRTOSConfig.h, then this
function will be called if pvPortMalloc() returns NULL because it has exhausted
the available FreeRTOS heap space. See */
void vApplicationMallocFailedHook( void )
for( ;; );
/* If configCHECK_FOR_STACK_OVERFLOW is set to either 1 or 2 in
FreeRTOSConfig.h, then this function will be called if a task overflows its
stack space. See */
void vApplicationStackOverflowHook( xTaskHandle pxTask, signed char *pcTaskName )
for( ;; );
/* If configUSE_IDLE_HOOK is set to 1 in FreeRTOSConfig.h, then this function
will be called on each iteration of the idle task. See */
void vApplicationIdleHook( void )
/* Just to prevent the variable getting optimised away. */
( void ) ulHighFrequencyTickCount;