FX3: enumeration USB2 on USB3 port

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
fmo_nn6
Level 1
Level 1
5 sign-ins First like received First reply posted

Hello,

On some laptops (mostly on recent models), our FX3 enumerates in USB2 although it is connected to an USB3 host. If we switch to another USB3 port on the same laptop, it seems to work fine. We have seen it happen on some "USB charging ports", but we are not totally sure this is related.
I found similar cases here:
https://community.cypress.com/t5/USB-Superspeed-Peripherals/CX3-Device-is-not-enumerated-as-USB3-0-d...
https://community.cypress.com/t5/Knowledge-Base-Articles/USB-3-0-Device-Enumerated-as-USB-2-0-KBA204...

Unfortunately the suggested solutions (hw or sw) did not help.
- We use USB type-B connector
- We disabled LPM 'CyU3PUsbLPMDisable()'
- We enabled SSD connection 'CyU3PConnectState(CyTrue, CyTrue)'
- We are in compliance with AN70707

I add that other USB3 devices such as external hard drives do work (in USB3) on these ports.

 

0 Likes
1 Solution
AliAsgar
Moderator
Moderator
Moderator
1000 replies posted 250 solutions authored 750 replies posted

Hello,

We compared your schematic to AN70707. Your schematic does not seem to obey the schematic checklist Sl No 3 and 7. Also can you confirm, 

1. If the capacitors are connected in the same configuration as given in the FX3 explorer kit schematic files.

2. If the precision resistors have 1% tolerance value.

The USB debug log for USBBulkSrcSink would help.

Best Regards

AliAsgar

View solution in original post

0 Likes
4 Replies
AliAsgar
Moderator
Moderator
Moderator
1000 replies posted 250 solutions authored 750 replies posted

Hello,

1. Could you verify if you have tried out all the solutions in the KBA .

2. Can we know on which host and host controller is the issued being seen on?

3. Could you please try out USBBulkSrcSink code on the FX3 and send us the USB debug prints/logs.

4. It would also help us a lot if you could send us the schematics of your FX3 board.

We recommend to use a short and certified USB cables for connecting the device to host.

 

Best Regards,

AliAsgar 

0 Likes
lock attach
Attachments are accessible only for community members.

Hello,

1. Yes we looked into that (HW and SW) as we already came through this post.
2. This is most generic host controller: USB3.0 eXtensible Host Controller
3. I'll have to get back to you on this...
4. Please see attachment

Regarding USB cables, we used several certified cables.

Regards

0 Likes
AliAsgar
Moderator
Moderator
Moderator
1000 replies posted 250 solutions authored 750 replies posted

Hello,

We compared your schematic to AN70707. Your schematic does not seem to obey the schematic checklist Sl No 3 and 7. Also can you confirm, 

1. If the capacitors are connected in the same configuration as given in the FX3 explorer kit schematic files.

2. If the precision resistors have 1% tolerance value.

The USB debug log for USBBulkSrcSink would help.

Best Regards

AliAsgar

0 Likes

Hello,

You are right about checklist items 3 and 7.
We did forget the ferrites on power supply and we are gonna try add them on a board and see if it solves the issue.
Regarding the LC on USB shield, this is more tricky. Actually we did not implement it on purpose cause our CEM engineer strongly advised us to ground shield directly... It seems this is quite debated among HW engineers (see here). But if you guys say it should be so, we will have to make the change for our next PCB revision, if you think this could make a difference... But is this really that significant in 'normal' CEM environments ?

I confirm that:
1. the capacitors are connected in the same configuration as given in the FX3 explorer kit schematic files.
2. the precision resistors have 1% tolerance value.

I will get back to you as soon as we can test the addition of inductions on power supply (as we may be able to do it on one board at no cost), and close the case if this did the trick.

Regards

 

0 Likes