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Custom hardware, cannot enumerate, VID/PID=0x0000 | Cypress Semiconductor

Custom hardware, cannot enumerate, VID/PID=0x0000

Summary: 3 Replies, Latest post by Zohair on 25 Mar 2012 10:47 PM PDT
Verified Answers: 0
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Zohair's picture
2 posts

I'm working on a custom board. After connecting the USB cable, Windows displays a  "USB Device not recognized" message. In device manager, the VID/PID pair are both 0000. I checked this by reading the "Device Instance Path" field. 

I checked the steps given in AN15456. I've checked all the voltages and they are all fine. The rest and Wakeup pins are also correctly set (Wakeup is pulled high). I am also getting the 12 MHz output wave on CLKOUT. The application note suggests that since Wakeup is high, SDA and SCL should be pulled up, which is also done. I do not have an EEPROM on the board so this matches the initial test sequence in the application note. Yet, I cannot get the chip to enumerate. 

Is it possible that this is a problem with the chip itself? Should I replace it? Or am I missing something simpler?

prji's picture
Cypress Employee
473 posts


     Please create a tech support case (MyAccount -> MyCases) so that one of our engineers can review your schematic.



zhangyj_123's picture
3 posts

If you use USB in High speed, make sure the power supply of USB interface is in good quality, using effective filter.

Zohair's picture
2 posts

 OK I think the problem was with the crystal I was using. I used a function generator and the device enumerated correctly.


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