Dennis Field / dvk-mx8m-bsb - History

Fit the new MHF4 footprint and antenna feedline together using the new footprint's dimensions

The MHF4 spec sheet gives dimensions for a 50Ohm CPW coming from it, however this feedline is actually a microstrip line and therefore it should follow our specific width requirements (using our relative permittivity and top-to-bottom spacing). The width of the feedline will need to be adjusted once the permittivity between the top and bottom layer with the inner layers being void is given/known (at ~3GHz).

Use MHF4 instead of U.FL connectors on the WiFi+BT antennae

Routed missing wires (ethernet part, SD-card passives, SD-card supply)
Shortened/straightened connection SD-card <-> SOM

Correct and complete the USB and HDMI serpentine bend skew/phase routing such that each diff pair is tuned/matched to 0mm. Place each of the tuning meanders at the correct corresponding locations by going down the line and setting each of the pairs' proceeding segment length to being an equal stub, checking the overall skew, making the correction near the problematic bend (so long as the next "correction" bend is >15mm away), and going down the entire line doing this.

Each of the diff pairs now have a 0mm intra-pair skew (with the exception of three very short USB-C pairs between the CMF&ESD IC and the receptacle) which still have a skew within the <1ps~=150um spec (is actually <100um).

Correct the spacing between USB1_TX_P&N on the top layer next to the SoM

Adjust the dimensions and move the placement of the serpentine bends to the recommended values & locations for the USB diff pairs and the HDMI CLK line

This same thing still needs to be applied to the other HDMI diff pairs.

Continue optimizing the HDMI diff pairs and use <2*Gap for the amplitude and <3*Width for the spacing on the USB serpentine routing

These same <2*Gap & <3*Width values still need to be applied to the HDMI diff pairs (along with placing the meander in the correct locations by deleting segments checking the length, and re-adding the segment).

Make the HDMI routing conform more closely to the clearance requirements (30mils between data diff pairs & 50mils from CLK) and add meanders to tune the skew/phase

Coarsely route HDMI diff pairs from the SoM to the CMF&ESD chips, place the microphone in a position that does not interfere with either the HDMI circuit or the RJ45

The HDMI diff pairs will need to try to have 30mil clearance between each other at every point possible, in tight spaces this is not possible, even spacing will need to be adjusted in the following commit.