The perfect debugging tool

I've made some big changes to this but I have a question for those used to debugging embedded micro hardware.

Given 16 bits of high-speed (hopefully 25MHz) storage that can be split between digital and analog what mix makes more sense?

8 bits AN (single ch)
8 bit DIG

or

10 bits AN (single ch)
6 bit DIG

Is dual AN channel really necessary?


Rob