USB Error Handling For Electrically Noisy Environments

[Anonymous]

Hi all,

we are currently struggling with USB connection instabilities with FX2 hispeed devices. We have been using them for long and they are generally quite stable. The present issues seem to (empirically) relate to electrically noisy environments. Symptoms vary a lot, from device not getting recognized to Control- or Bulk Xfers failing.

Now I stumbled over the Cypress Appnote 1036

"January 15, 2002

Document No. 001-17096 Rev. ** 1

USB Error Handling For Electrically Noisy Environments"

found at http://www.cypress.com/file/74566/download

It basically says that in such cases the device driver should do some more error handling.  However, it is very old.

Could anyone tell me to what extent the Cypress drivers (CYUSB, CYUSB3) are actually implementing this and maybe from what version?

Anyy other help regarding diagnostics or debug strategies for such issues would be much appreciated.

Thanks,

MIchael Wahl

[SrinathS_16]

Hello Michael Wahl,

Please update the driver to the latest version(1.2.3.20) from the FX3 SDK and let us know the behavior.

http://www.cypress.com/documentation/software-and-drivers/ez-usb-fx3-software-development-kit ​

Best regards,

Srinath S

[Anonymous]

Hello Srinath,

thank you for answering, but this approach is not so helpful. The driver interface is now quite different and porting the (pretty old) application to the new driver will take time. Testing it is extra complicated because we would have to roll it out to customers in the field where the issues are being observed. Apparently only there the noise issues exist. Here at home base we do not see the errors. This is why I was hoping to learn from which version of the driver you might have introduced more robust error handling, in order to decide whether porting to that new driver makes sense.

Thank you,

Michael

[SrinathS_16 · Accepted solution]

Hello Michael Wahl,

- Cypress drivers implement the reporting of USBD errors to the host application which implement the handling of these errors. This is to make the drivers generic. Cypress drivers in itself do not have any special implementation to handle electrical noise.

- Also, it has to be noted that the support for older Cypress drivers is no longer present and customers are requested to migrate to the latest CyUSB3 drivers.

Best regards,

Srinath S