Laying out a uC

[Harvs]

So when laying out board with SMD uCs using both the ADC and switching signals, what order generally works best?

e.g. do you start with decoupling caps, then the analog side and any associated guard tracks, then move onto the digital stuff etc.

Obviously there's exceptions.  And I guess there'll be cases where there's clear high priority signals... But just wondering if there's generally a "best" way to start?

[Psi]

Most mcu datasheets have a recommended track/groundplane layout for around the ADC pins.

[richcj10]

If it is a 4 layer, I put the caps under the uC on the bottom layer.
If it is a 2 layer, I put the caps next to the pins and route out from there.

[Kremmen]

I have had good success with 2 layer boards by placing the bypass caps directly under the MCU power pins on the board back side and then connecting with minimum length vias to the power pins. The other end of the cap just goes to the ground plane that is flood filled all over the back side.