Understanding Interrupts

I believe I have the querying function attached to the overflow. So my understanding is that it would be called overtime there is an overflow on that interrupt, which would be at a regular time step.

PeterH, thank you for your suggestion. That does make a lot more sense. I am curious about this process though. Above it appears there are two different answers from CrossRoads and groundfungus:

  1. The while loop finishes and then the ISR is executed
  2. The while loop pauses until the ISR is finished.

Any sense of which it is?