how to balance both of them, please give some advice,thanks

In my opinion it is necessary to use both aspects. They are important and very useful in different situations.  It will be very good if both approaches are implemented in the technical descriptions and users can switch from one to another.

The first aspect has already implemented in Hardware Description. I would advise you to add the references to the documents describing an essence of these functions in detail.

The second one  is very useful in some situations.  It seems to  me the on-line form is the most interesting implementation of this aspect. This on-line form must provide the choice of feature and  the search of all product versions which support this feature. As well as you can make ordinary document in table form with information about conformity between the features and the product versions. This document must contain the references to the complete description of boards (Hardware Description).

 

jonathan.cohen, I suggest that you  place the first version of the documentation at the Community. All of us together will  evaluate it and  recommend the further ways.

Maybe adding a matching table between versions its the best. I mean adding in each document of each version an annex table with the different features of the manual version and the older versions. That would be really great! Do i explain my self?