as the title, USB2 and USB3 need to be paired?
If only USB2.0#1 is with deviceA and USB3.0#1 is with deviceB, there is ok situation?
Like The NX have 3 USB2.0 and 3 USB3.0, it can connect 6 different deviess?
Thanks for replying.
You can use USB2 ports and USB3 ports as host ports independently, if needed, like some ports can support USB2 only and some can be connected to USB3 devices only.
If we place 6 typec connector that trace is only USB2.0 for 3 ports and only USB3.0 for 3 ports, there is ok?
Hi @water_hong
This is not correct. USB3 must be paired with USB2.
Recommend to use USB hub if you need additional USB ports.
Just some trivia on the topic which you might find useful…
When USB evolved from the 1.0 to 1.1 to 2.0 releases each new controller had the ability to work with older standards and not just for the controller’s main standard. For example, any USB 2.0 controller also has the ability to work with a 1.0 or 1.1 release.
In USB3 this all changed. The controller is a dedicated USB3 controller. Extra wiring is used for any USB socket which works with both USB3 and older USB modes. In the case of seeing USB3 the wiring for that is routed to the USB3 controller, but if USB2 or older is seen, then the wiring routes to a different controller.
If you have a tree view of lsusb (“lsusb -t”), and you have a USB2 port (not USB3), and you were to plug different devices into it (via a hub), and if each device has a different standard (e.g., a USB2 external disk drive and a mouse and keyboard), then each will show they are served by the same controller; only the speeds will differ (tree view of lsusb shows speeds).
If you have a USB3 device going to a socket via a HUB, and you also have a slower USB device, then that same tree view will report different controllers. Everything USB 2.0 or slower will go to the legacy controller, and everything USB3 will go to the dedicated USB3 controller.
The information used to find the right controller (other than physical wiring) will be in the device tree. Drivers for the legacy and USB3 controllers might need device tree information to inform them of that relationship.
Just to clarify the limitation about what software cannot support
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You could not use usb3 port alone without paired with any usb2 port.
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You could not use usb2 signal that is behind a hub to another usb3 signal from Jetson to paired and become a USB3 port.
If we place 6 typec connector that trace is only USB2.0 for 3 ports and only USB3.0 for 3 ports, there is ok?
Sorry, the correct question is we would like to design 3 USB2.0 and 3 USB3.0 to connect to devices independently on board.
In other words, the nets of USB2.0(D+/D-) connect to devices A,B,C for USB2.0 only and the nets of USB3.0(tx/rx) connect to device D,E,F for USB3.0 only on board. So we can have maximum 6 devices used on board?
That is not supported. As I already mentioned, USB3 could not work alone without any USB2 paired with it.