OAK SoM Pro - is USB2.0 necessary?

Question

OAK SoM Pro - is USB2.0 necessary?

0y8w1x opened this issue 2 years ago · 9 comments

hey, I'm designing a board with the OAK SoM Pro and saw that the SoM breaks out USB_D_N and USB_D_P, pin 90 and pin92 respectively. Is that lane necessary to route to the host, or can the device operate normally without that USB2.0 lane?

Answer 1 · 2023-02-21T06:24:14.000Z

@0y8w1x USB2 can be used as side channel for debugging and it is highly recommended to route it to the SoM-Pro at least on the new designs unless you are certain that you don't need it. I don't know for sure if USB2 is mandatory in case you would need to flash the NoR with pipeline/bootloader, but can be that you can use only SS pairs for that as well.
CC: @Erol444 on USB flashing over USB3

Answer 2 · 2023-02-21T11:56:35.000Z

@Luxonis-David USB flashing over USB3 only (before BL, etc...) is not possible. Internal BL supports USB2.

Answer 3 · 2023-02-21T12:08:09.000Z

Thanks @themarpe, @0y8w1x routing USB2 is necessary.

Answer 4 · 2023-02-21T17:44:12.000Z

thanks. I'd like to ask then, is it possible to use the USB2.0 lane on a seperate USB connector? lets say to only flash the bootloader over the USB2.0 connector, and use the device after that with only the SS lanes?

Answer 5 · 2023-02-21T17:46:35.000Z

Yes that is possible, not sure what would be the reason though?

Answer 6 · 2023-02-21T18:13:42.000Z

here is what's going on, the main IC in my design has 1x type-c input (alt mode pin assignment D) and 1x USB3.0 input. it then muxes the ML and USB3.0 together on one type-c output. with 'type-c' input I mean 2x SS pairs and 1x USB2.0 plus cc and so on. and then I only have one USB3.0 lane left. the manufacturer suggests a USB2.0 hub, but I don't want to do this if there is an easier alternative. and it sounds like I don't need it for normal operation, just once to flash the bootloader. and on top of that the routing is nicer ^^

Answer 7 · 2023-02-22T10:47:55.000Z

I don't think I follow the above architecture description, if you would need any assistance would you be able to provide a simplified block diagram explaining the architecture you are mentioning?

Answer 8 · 2023-02-22T11:34:59.000Z

let me know if this explains it better

*edit: and a solution that would be possible, is to use a USB2.0 hub, where the input is the type-c receptacle and the oak som USB2.0, which then outputs into the asic

Answer 9 · 2023-02-22T14:25:43.000Z

Yes using HUB would be best in this case if you need to go through ASIC or need ASIC connected to USB2.