FX3 Board Bring-up Issue

[Anonymous]

We are trying to bring-up a board with FX3. Unfortunately, we are unable to get any response from FX3 over USB port. Ideally we will upload our firmware over USB but when we plug USB cable we see nothing on the other hand of the cable. We at least expect a new USB device found message from the USB bus assuming USB 2.0 should work out of the box. FX3 is completely dead. We double checked mode pins and all related functionality. Can anyone shed some light about what is missing on our design? I'm attaching related schematics to the message.

   

Thanks in advance,

   

Caglar

[Anonymous]

Please match the schematics against the hardware guidelines provide from Cypress. AN70707: http://www.cypress.com/documentation/application-notes/an70707-ez-usb-fx3-fx3s-hardware-design-guide...

   

Next check the PMODE pins, and ensure that they are set as per USB boot. 

   

Is it happening on one of your boards, or you see the same behavior on multiple boards?

[Anonymous]

Thanks for your valuable comment. Given that there is nothing else to look for, we digged the hardware and problem turned-out to be a crystal/oscillator problem.