aviasaf wrote on Wednesday, February 18, 2009:

hello all,

I am working on atmel at91sam7s256 base on IAR workbench 5.00.

the semaphore example which appears in FreeRtos Web site uses portYIELD_FROM_ISR macro,

its being called after xSemaphoreGiveFromISR and if xHigherPriorityTaskWoken was set to true.

first of all, I would like to understand, what is the Yield macro role ? is it uses in order to force a context switch after the interrupt routine is ended?

second, I didn’t found portYIELD_FROM_ISR macro at all, so I was trying to use “taskYIELD” but the OS was crashed.

what am I doing wrong?

does any one can help me with that problem?


davedoors wrote on Wednesday, February 18, 2009:

There is an example given under "interrupt service routines" on this page http://www.freertos.org/portsam7iar.html and most likely in the demo for your port as well.