USB 3.2 and USB 2.0 Clarifications

Robotics & Edge Computing Jetson Systems Jetson Thor
1

Hi,
I wanted some clarifications regarding few interfaces on Jetson T5000 SoM. I am referring Datasheet, design guide and Technical reference manual which confuses me often.

1.) I learnt that all the ports of USB 2.0 supports host mode and i am also convinced that any one USB port of 2.0 or 3.2 can be in device mode. But I am not clear if all the ports of USB2.0 and USB 3.2 supports device modes or is it just restricted to USB 2.0 port 0 only and USB 3.2 UPHY1 TX1/RX1 only ?

2.) Does all the USB 3.2 (total 3 ports) support 10Gbps speeds independently. I read in the design document that Port 1 and Port 2 uses shared bandwidth of 10Gbps. Can you please confirm me about the same ?

3.) Is there a constraint to map USB 2.0 and USB 3.2 lines to a connector ? Can i separately use all the USB lines totaling 7x separate lines (3x USB 3.2 and 4x USB2.0) ?

Please could you clarify on the above queries ?

3

There is conflicting information about device mode for the USB 2.0 ports between the Data Sheet and the Design Guide. I am clarifying internally.

For USB 3.2, any of the ports can be device mode but only one port at a time. Note as per the Data Sheet section 4.3.2: In device mode, the USB3.2 controller supports Gen1 Super Speed.

The Data Sheet mentions: There is an internal USB 3.2 hub for ports 0 and 1. The hub supports 10Gbps bandwidth which would be shared between the two ports.

So P0 and P1 would share 10Gbps and P2 itself is 10Gbps.

image
image889Ă—197 13.8 KB

USB 3.2 ports require USB 2.0, otherwise it violates the USB spec. Many devices rely on USB 2.0 for detection and compatibility. So any port with USB 3.2 must also have USB 2.0.

1 Like
5

Kindly Confirm the Device about information for USB 2.0

7

Yes, every USB2 port could be device mode but only one port could be running as device mode at same time.

1 Like
8

That means, all the ports of USB2.0 and USB3.2 support Device or host mode. But only one of the any port in both the USBs support device mode at a time. Am i correct ?

9

Correct.

And because each USB 3.2 port should have a USB 2.0 mapped with it, the ones in “device” mode should be on the same physical USB port.

10

For RCM, How should i map the USB 3.2 and USB2.0 lanes to the connector ? As per my understanding, For RCM to support both USB 3.2 and USB2.0 modes, i need to Map USB2.0 USB0_N/P Lane with USB3.0 UPHY_RX1/TX1 lane. Is my point correct ? Please correct me if i am wrong.

image
image1093Ă—425 42.3 KB

11

Actually we don’t support recovery mode in USB3 speed due to software limitation.

Thus, you could ignore that part and just focus on USB2.

1 Like
12

Hi,
After mapping the 3x USB 2.0 with 3x USB3.2, There will be one more USB2.0 remaining. Can i use it as a Normal USB 2.0 Type A connector ? I Assume there shouldn’t be a problem for Hot plugging/Enumeration

13

Yes you can.

15

This topic was automatically closed 14 days after the last reply. New replies are no longer allowed.