Dennis Field / dvk-mx8m-bsb - History

Make the rest of the silkscreen designators visible (some must be underneath the RJ45 and battery holder), add silkscreen which identifies the mPCIe and M.2 card slots

Added a "layer indicator" (useful for handling in the board house)
Currently placed under the mPCI card, but other locations possible.

Move device designators on silkscreen layer to reasonable places where they are readable and not covered by obstacles.
This was not possible on all areas of the F.Silk layer, because there exist four spots with a very high density of components:
-Audio circuit
-Ethernet circuit
-USB-C circuit
-Components below the SIM socket.

Move some of the reference designators on the silkscreen layers to more visible positions where possible, update the schematic, BoM, footprint, and layout to reflect the fact that the dual 2-input AND gate (U1803) is actually a 74AUP2G08* part (no longer *LVC*)

The rest of the silkscreen designators still need to be placed in more visible/unobstructed locations. The BoM still needs to have tolerance & rating values enter for all passive components that will be supplied by the PCBA house.

Add user-facing universal icons/symbols which will help the users identify common buttons/receptacles/sockes

Make a few more minor adjustments and export preliminary gerber files

The gerbers will be re-exported frequenty from now until the final prototype files, after which point the revision will need to be incremented if further changes are made.

Make the ENET_* traces on the top layer 53mils in order to ensure they have a 50Ohm single-ended impedence, move one of the 5V_P bypass caps close to the SoM end of the USB2 diff pair, add meanders to the ENET_TXC, ENET_TX_CTL, ENET_RX_CTL in order to ensure these segments are matched to the long ENET_RXC segment (56.051mm, the rest of the RGMII signals are <10mm skew from this length and don't need adjusting, re-route the SIM card such that UIM-RESET is routed in between UIM-CLK and UIM-DATA as recommended by a BB manufacturer

Rework length adjustment of SD card (one signal was too long).
Changed width of RGMII traces to 0.127 mm.
Removed unnecessary tiny segments/stubs.

Length matching of SDCard signals.
Increasing distance between signals and creating meanders.

Increased distances of reduced gigabit media-independent interface (RGMII) signals
in order to be able to adjust trace lengths.