sleep vs hardware condition SW problem.

[Altera_Forum]

hello, I have a problem I am not sure how to tackle. I have a niosII system with some custom HW blocks around it. One of them generates a PID locked indication signal.  

 I would like to have the nios wait for this line to come high or sleep for 40ms whichever happens first.   I am running microC-OSII.   I would like to let the processor run other tasks while it waits for this hardware line to go high or for the timer to expire.   Is there an elegant way to achieve this without polling the line and hogging the CPU?

[Altera_Forum]

Interrupts

[Altera_Forum]

possibly setting up an interrupt would work, but how do I keep track of the 40ms? 

 If I could reliably depend on my HW to converge in time I wouldn't need a timer and an interrupt would be straight forward.   But I need the 40ms timer as backup in case the HW doesn't converge in 40ms.

[Altera_Forum]

That would be a timer interrupt then :-) 

Probably the OS you are using has functions for that!