Details on PCB layout for microcontroller
No, you should not. And get rid of the so called &quot;local ground&quot;. What do you think is happening with all the digital signals when you implement this local ground? You should find the answer in Henry Ott's article that you linked, Figure 1.
Sure, you do have a connection between local ground and the ground plane, but all you do is increase the loop area, essentially turning your trances into small antennae.

That sounds fine.

The reference manual says that VREF- must be connected to VSSA which in turn must be connected to VSS. I suggest that you just connect the VREF- directly to ground and try to keep digital currents out of the way using clever placement.


As for the suggestions, if 1uF caps are the only components you plan to place on the bottom, I recommend that you place them on top. When you have components on both sides, the manufacturer either has to run the board through the oven twice, or solder the components by hand. Both of which will increase the manufacturing cost.