USB 3.1 Gen 2 HUB with multiple USB 3.0 cameras


I consider Xavier NX custom board.
I wanna make several information clear about USB camera.

First, I’ve seen RTS 5489-GR is reference on following link and carrier board designs file’s schematic.
=> Porting USB → Required Device Tree Changes
And Product Design Guide comments both RTS 5420(Ch3-2_p.8) and RTS 5489-GR(Ch.3_p.7).
Following Forums answer RTS 5420 is reference.
=> NVIDIA Jetson NX Developer Board Part Unavailable - RTS5489-GR
Can I use both RTS 5489-GR and RTS 5420?
Or can I use only RTS 5420?

Second, I wanna connect 3 or 4 multple USB3.0 (USB3.1 gen 1) cameras through SSHUB.
All USB port A on Developer Kit were specified for USB 3.0 from carrier board specification.
So, It is fine with carrier board design, but I have to check this Note.
Note: Some non-compliant USB 3.0 devices will not function correctly unless USB 3.1 Gen2 is disabled.
What USB 3.0 is compliant or not? How can I check it?

Third, I have a question for bandwidth if the second question is possible.
I refer following forum and Xavier Series Soc Reference Manual.
=> How to change USB3 port speed to gen1
Each dual port shares 10 Gbps. It means It can be possible to use 4 port of USB 3.0 Cameras for bandwidth side.
But, I’m not sure it from following comments : SuperSpeedPlus hub, due to scheduling policy reasons each SuperSpeed device may not be able sustain the full SuperSpeed unit bandwidth if the other is device is active.
For example, port 1 ans port 2 share 10 Gbps total bandwidth.
And port 1 and port 2 connect to USB 3.0 Camera with 5 Gbps respectively.
This bandwidth looks fine.
And then I wanna check device access or scheduling side are fine or not.
Can I get the image data same time from each camera?

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  1. RTS5420 is public part number of RTS5489, they are same thing.
  2. You can check the USB device datasheet or vendor.
  3. It depends on how your driver handle the data, for Jetson hardware, it is USB port only.
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