P3960-TS3: recommended topology for connecting more than four 100BASE-T1 sensors

DRIVE OS Version: 7.0.3
Hardware Platform: DRIVE AGX Thor Developer Kit (P3960-TS3) - SKU12

Issue Description:

On P3960-TS3 the only 100M-BASE-T1 ports are M_Switch (88Q5152) P3-P6, exposed on the H-MTD x6 connector J3 at positions 2, 3, 4 and 5. Every other BASE-T1 port on the platform is 1G or 10G.

We need to attach more than 10 sensors whose PHYs are fixed at 100BASE-T1 in Secondary role and cannot be reconfigured on the sensor side. Four ports is not enough.

I have already read the following and understand that port speed and T1 role are set in sMCU / switch firmware and are not changeable from DriveOS.

So I am not asking for a firmware change in this thread (but if now it is possible, please tell me). What I would like to know is:

  1. What is NVIDIA’s recommended topology for attaching more than four 100BASE-T1 sensors to a Drive AGX Thor platform? Is there an external automotive Ethernet aggregation switch that NVIDIA has validated against DRIVE AGX, and which Thor port would you recommend as the uplink (1G-T1 on J3, or 10G-T1 on J2 position 2)?

  2. Can any RTL907xD port be configured at 100M-BASE-T1? Neither the TS2 nor the TS3 table shows 100M on those switches, so I assume not, but I would prefer this confirmed rather than inferred.

  3. If we aggregate through an external switch, are there any known gPTP / 802.1AS constraints for DriveWorks sensor time synchronisation across that additional hop?

The specific sensor models do not change the question - this is a port count and port capability issue - but I can share those details by private message if it helps.

Thank you.

Dear @riccardo.briccola1 ,
Changing PHY speeds, switch port speeds/roles are out side forum support scope. Please reach out to switch vendor to see if FW can be provided as per your need. Also, please reach out to your NVIDIA representative with use case details if support from any other NVIDIA channel be provided for this use case.