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device not recognised as superspeed | Cypress Semiconductor

device not recognised as superspeed

Summary: 6 Replies, Latest post by Servaes.Joordens_1509071 on 13 Apr 2016 03:27 AM PDT
Verified Answers: 0
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I made a custom board with a FX3 and a USB type C connector. There is a ANX7408 in between the connector and the FX3 to interface.

The problem I face is that if I connect the USB cable in one orientation everything is fine and the device is recognised as a superspeed device.

When I rotate the Type-C connector to the other orientation, the superspeed is not recognised and I can only use the device as a USB2 device.

I suspect that the signal integrity causes the behaviour, but I a searching for more clues about this.


Can anyone explain the mechanism how the USB connections decides whether to use Superspeed or not?




Krishna GSNS's picture
Cypress Employee
32 posts


how you are determining the orientation of type - C using FX3 firmware. Please create a tech support case and provide all the necessary details.



hi Krishna,

I have an interface ic that handles the orientation problem (That is the AN7408)

Can you explain to the on what basis the FX3 decides not to use Superspeed?



kash's picture
Cypress Employee
112 posts

FX3 does not decides this. As per the USB spec, the host has the ability to put the device in SS or HS mode.

For more details you can refer to section 7.5 of the USB 3.1 specification. The host will first check if the device supports SS. If those tests fails it will put the device in to HS mode. 

So the decision is made by the host side, not by the FX3?

Based on what is this decision made? I guess there is some initialisation routine at the beginning of the connection?

Can I overrule this decision?

I will check the documentation you refer to.  


kash's picture
Cypress Employee
112 posts

Yes, the decision is made by host side. Yes, there is an initialization routine.

No you cannot overrule this.


thank you, useful knowledge!

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