Yielding from ISR on dsPIC

anonymous wrote on Monday, November 14, 2011:

I’m using FreeRTOS on a dsPIC and want to give a semaphore from an ISR. The xSemaphoreGiveFromISR macro is being called but in all of the documentation it talks about yielding from within the ISR. The actual implementation depends on the port. some ports use taskYIELD. There is a version for the PIC32 that is named portEND_SWITCHING_ISR but I can’t find an implementation for the dsPIC. Has anyone implemented this and if so, do you want to share the solution? I’m in crunch mode and don’t have time to re-invent the wheel. If nobody has the solution I will implement it and post the code for all to use.

rtel wrote on Monday, November 14, 2011:

See the “Interrupt Service Routines” section of http://www.freertos.org/portpic24_dspic.html, and the example in _U2RXInterrupt() defined within FreeRTOS\Demo\PIC24_MPLAB\serial\serial.c.


richard_damon wrote on Monday, November 14, 2011:

If you want to make the code look the same for PIC32 and dsPIC, you can define

#define portEND_SWITCHING_ISR( xSwitchRequired ) 	\
{													\
	if( xSwitchRequired ) 							\
	{												\
		portYIELD();        						\
	}												\

anonymous wrote on Wednesday, November 16, 2011:

Thank you for the replies. I used the taskYIELD() function and it seems to be working fine. I’m having stack overflow problems but I’m convinced it’s elsewhere in the code. I had tried the taskYEILD before but thought it was causing the stack overflows. Now I’m pretty sure it’s not the cause.