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portYIELD_FROM_ISR + atmega32

Posted by zvonko on May 12, 2010
hi, this is the sample code from freertos website
, how do i use portYIEED_FROM_ISR with atmega32, i cant find this macro in the portable code,
or can i just use taskYIELD() macro inside an ISR ?

/* Timer ISR */
void vTimerISR( void * pvParameters )
static unsigned portCHAR ucLocalTickCount = 0;
static signed portBASE_TYPE xHigherPriorityTaskWoken;

/* A timer tick has occurred. */

... Do other time functions.

/* Is it time for vATask() to run? */
xHigherPriorityTaskWoken = pdFALSE;
if( ucLocalTickCount >= TICKS_TO_WAIT )
/* Unblock the task by releasing the semaphore. */
xSemaphoreGiveFromISR( xSemaphore, &xHigherPriorityTaskWoken );

/* Reset the count so we release the semaphore again in 10 ticks time. */
ucLocalTickCount = 0;

/* If xHigherPriorityTaskWoken was set to true you
we should yield. The actual macro used here is
port specific. */
portYIELD_FROM_ISR( xHigherPriorityTaskWoken );

RE: portYIELD_FROM_ISR + atmega32

Posted by Richard on May 12, 2010
portYIELD_FROM_ISR() does not exist for the 8 bit AVR - hence you cannot find it. You can use taskYIELD() directly, but only as the last instruction in an interrupt handler.

Take a look at the SIGNAL( SIG_UART_RECV ) function in FreeRTOS/Demo/AVR_ATMega323_WinAVR/serial/serial.c for a GCC example. Alternatively take a look at __interrupt void SIG_UART_RECV( void ) in FreeRTOS/Demo/AVR_ATMega323_IAR/serial/serial.c for an IAR example.


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