I'm trying to design a system that will operate fairly consistently over a wide range of temperatures. So far, I've been using the internal RC oscillator that my ATmega324P provides. However I've read that this oscillator is temperature and voltage dependent.
As a solution I'm looking into external crystals. The datasheet for the device refers to everything as a crystal oscillator. Do they, in fact, mean an oscillator with its own power source or will the processor be able to drive a passive crystal?