Re: PCB layer stack
It sounds like you are in over your head with this design. I don't mean that as an insult; however, you seem not to understand the many factors that drive board stackup.
First, to prevent board warpage and twist, it is usually a good idea to keep the number of planes even and the number of signal layers even. They are arranged about the central core of the board in symmetric pairs. This is a mechanical consideration.
Next, to prevent signal reflection, you control impedance on the signal traces carrying fast risetime or high frequency signals. This is done by either making the signal paths broadside or edge coupled differential pairs, or by referencing the traces to an adjacent plane. The width of the trace, the permitivity of the board dielectric, and the spacing between signal trace and its return path on a plane or parallel trace will determine the trace impedance.
Next, to improve noise rejection on the power planes, it is frequently a good idea to close-couple the power plane to a ground plane. Distributed decoupling capacitors may also have to be employed depending on the types of devices, risetimes, and signal power levels.
Next, you must consider the unwanted cross coupling that can occur if there are parallel traces on adjacent layers that are not intended as differential pairs.
Next, you must consider the return paths on the planes. You do not want high energy and/or fast risetime signals sharing a return loop. If they do, you will modulate one signal with the other on the return side - you lose signal integrity.
Next, you must consider radiated signals. Some fast and/or high energy signals may have to be buried on an inner layer with adjacent planes to shield them from coupling to external structures or devices. This will be very important if you are to pass EMC testing. Other techniques may be necessary to prevent radiated interferrence - such as ground via stiching. Burying certain signals may also be required if those signals are very sensitive and need to be well shielded from outside interference.
There are many considerations that depend on just what you are trying to design, signal strengths, frequency, mechanical considerations, product test requirements, manufacturability, etc.
There are several books that I can recommend, but none of them is a cookbook that will tell you how to stack a board based on the number of desired layers. The number of layers is generally the result of careful layout planning for specific board performance.
As a start, you could take a look at the books listed on the following:
**broken link removed**
**broken link removed**