Importance of Impedance Matching

Because rise/fall time is not a function of the driver but rather the entire circuit (taking in to account current strength, load capacitance, resistance, termination, etc.) you will not find it in a datasheet.

Once again, for what you are doing, you probably don't need to put so much effort into it. If your company has access to a board level simulation tool such as Mentor's Hyperlynx, that is an excellent way to simulate and visually see what effects the different components have on a circuit. You can actually lay out your trace with the CPLD pin and see what the signal looks like.

With regards to ringing. Usually ringing is an effect caused by the other issues (reflections due to impedance mismatch, improper terminations, improper trace layout, uncompensated inductance or capacitance, etc.) Actually in my experience the largest contributor to ringing is improper grounding. A weak current return path is guaranteed to give you ringing.

Jake