HX3 only USB2 is working

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Sag
Level 3
Level 3
First like received 25 replies posted 25 sign-ins

Hey,

I have designed a board with the HX3 with 1 US and 2 DS ports.

Looks like it is working only as USB2, I mean when I connect a USB2 camera it works ok, but when connecting a USB3 camera it does now work.

What can be the problem?

P.s

I'm working with internal ROM boot.

 

Thanks,

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1 Solution
Ajeethkumar_P
Moderator
Moderator
Moderator
50 likes received 500 replies posted 100 solutions authored

Hi,

Please find the comments below:

  1. TX1 & RX1/TX2/RX2 pair should not be shorted on the type-c connected due to the following reason: (Root cause for SS Not working)
    • Creates the stub and will cause reflection on these lines. Hence signal integrity will be lost.
      • I would recommend the mux( PI5USB30213AXEAEX - This has built-in Pull Down for CC lines) with built-in CC control for connecting 2 pairs of SS lines on a type-C connector.
  2. 1.2V regulator should be ripple less than 20mV.
  3. On the layout :
    • Can you share the complete layout if it is not confidential?
    • Based on the snapshot, I see the vias are placed on these RX and TX lines. These vias make no connection or partial connection between the actual RX and TX vias. This can also be a root cause of the SS issue.

Ajeethkumar_0-1644394201875.jpeg

 

Thanks,

Ajeeth

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Ajeethkumar_P
Moderator
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50 likes received 500 replies posted 100 solutions authored

Hi,

1. What is the part number of the HX3 you are using? Is it CYUSB230x?
2. If not confidential, can you share the schematics of your design?

Thanks,
Ajeeth

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hey,

The part number is CYUSB3304, the schematics are attached.
I can also add that further analysis showed that when connecting the board to a USB3 port  in my PC I can see that a USB2 hub is exposed  in the device manager, when I connect the HX3 kit CY4609 I see both USB2 and USB3 hubs exposed in the device manager

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Ajeethkumar_P
Moderator
Moderator
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50 likes received 500 replies posted 100 solutions authored

Hi,

Thanks for sharing the above information.

Please share the following:
1. Schematics looks fine. Can you fill out the layout checklist on Page 22 of the HX3 hardware design guidelines document and share it with us?
2. Do you have a USB analyzer? If so, can you please share the HX3 Hub enumeration logs?

Thanks,
Ajeeth

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hey,

attached you can find the check list, you can see i marked X at gourd traces because we did not fill a lot of vias (i added a picture of the DS1 TX and RX so you can see), and also marked X on vias since we did not have a choice and had to place few vias to the traces to reach both A and B row if the type C connector.

currently we don't have a USB analyzer

thanks, 

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Ajeethkumar_P
Moderator
Moderator
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50 likes received 500 replies posted 100 solutions authored

Hi,

From the shared PCB layout, there is

  1. No Port-to-Port Isolation
    • Port-to-port isolation is required to minimize the effect of the interference fringes of SS Tx lines of one port over the Rx lines of another port. Fill the space between two differential pairs with Ground.
  2. No Ground vias next to signal vias
    • Vias introduce discontinuities in the signal line and affect the SS signal quality. If you need to route the SS signal to another layer, maintain continuous grounding to ensure uniform impedance throughout.

Please follow the "Routing of USB Data Lines" section of the "HX3 Hardware design guidelines" document.

You can also refer to the HX3PD(Infineon Type C Hub) DVK CY6611 PCB layout for your reference.

Thanks,
Ajeeth

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Hey,

i will check with an analyzer and upload the images so we can confirm if it's a layout issue.

but are there any other reasons for this not to work?

 

thanks, 

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Ajeethkumar_P
Moderator
Moderator
Moderator
50 likes received 500 replies posted 100 solutions authored

Hi,

Sure. We can analyze if the analyzer logs were available.

As the only difference on DS ports between your custom board and CY4609 is the layout(as you followed all other hardware design guidelines), I don't think of any reason that caused this issue.

Thanks,
Ajeeth

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Hey,

I was wondering if the problem maybe related to the USB-C connector used. should the CC lines and SBU lines be left NC? is the connection between row A and row B good? maybe the USB cable needs to be a special one?

appreciate the help

 

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Ajeethkumar_P
Moderator
Moderator
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50 likes received 500 replies posted 100 solutions authored

Hi,

From your Schematics, All the VBUS from Type-C is not shorted. 

The SBU lines can be left unconnected. But the CC lines should be Pulled High(for source - DS ports) and Pulled Low(for sink - US Port).

No special cable is needed. Any Type c cable will work.

Do you need PD to be enabled for the hub?

Thanks,

Ajeeth

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Hey,

we fixed the VBUS mistake.

about CC lines, if i understand correctly the US port in out board is the SINK and it should be pulled low, both should be pulled low?

we don't need PD in our hub.

thanks for the help

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Ajeethkumar_P
Moderator
Moderator
Moderator
50 likes received 500 replies posted 100 solutions authored

Hi,

Please find the comments below:

  1. TX1 & RX1/TX2/RX2 pair should not be shorted on the type-c connected due to the following reason: (Root cause for SS Not working)
    • Creates the stub and will cause reflection on these lines. Hence signal integrity will be lost.
      • I would recommend the mux( PI5USB30213AXEAEX - This has built-in Pull Down for CC lines) with built-in CC control for connecting 2 pairs of SS lines on a type-C connector.
  2. 1.2V regulator should be ripple less than 20mV.
  3. On the layout :
    • Can you share the complete layout if it is not confidential?
    • Based on the snapshot, I see the vias are placed on these RX and TX lines. These vias make no connection or partial connection between the actual RX and TX vias. This can also be a root cause of the SS issue.

Ajeethkumar_0-1644394201875.jpeg

 

Thanks,

Ajeeth

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Hey Ajeeth,

Appreciate the help, we'll implement the fixes you suggested and submit the layout for review.

thanks, 

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