Primary design choiced are made: Pinout is kept compatible to little brother Soft Propeller.
USB PHY and micro-USB Connector
Pin headers on the top (3 times 2x5) are removed
Decisions to make:
PCB Technology - target tech is currently 1+6+1 HDI, no stacked via, no via fill, no via in pad. This should be sufficient, but will be finalized during preliminary routing.
DCDC Converters, as there are now many more components in about same area as Soft Propeller v1.0, it may be necessary to change some DCDC converters to smaller footprint ones at the expense of higher cost.
It is open if the si1143 based 2D gesture support can remain, maybe :)
I have had some very similar drawn in sketchbook for decades. It has had different names, one I remember was "panncake computer". I think the panncake computer design was targeting about same used PCB area as DIP40 does. Well the list features and possible uses was not comparable to what is possible today.