New project, internal clock was fine for my previous first with project with the part, and I am at the pin assignment and product functionality part of the next. I may want to time an event with more precision than the internal clock. With an external crystal taking up two pins, I have none left for the timing function or have to give up some other function. Can I just use one of those oscillator modules? EXTAL seem right for the connection but I have not yet located a clear cut statement in the data sheet to that effect. Cost is not much of an issue.