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Failure of CY7C68013A to connect despite using known good firmware | Cypress Semiconductor

Failure of CY7C68013A to connect despite using known good firmware

Summary: 2 Replies, Latest post by Terry Platt on 24 Sep 2016 11:35 PM PDT
Verified Answers: 0
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Terry Platt's picture
User
5 posts

Hi, We have a new camera interface PCB that uses an FX2LP chip (100 pin version) for communications. Despite checking many times for track errors etc., this board always fails with a 'Invalid device Descriptor' report when booting from its eeprom. It will start OK if the eeprom is empty, but the functional firmware always causes the descriptor problem. The strange thing is that this firmware works fine in an earlier version of the same PCB, but we are unable to discover the physical difference between it and the new one. We have tried extra decoupling of the 3.3v supply, ground links between earth lands, and have replaced the devices several times. Is there anything that we have forgotten to try? Is any particular device pin especially critical?

Any ideas will be very welcome!

Regards,

Terry

mady's picture
Cypress Employee
1113 posts

Hi,

Does any other firmware work fine with this board? Or does it always fail with this particular firmware?

Please get the schematics and layout of the new version of the board reviewed by Cypress.

Regards,

- Madhu Sudhan

 

Terry Platt's picture
User
5 posts

Hi Madhu,

Many thanks for your reply. I have now located the cause of the problem - our firmware was sitting right on the maximum 16K limit and must have just exceeded it on this iteration. A slightly smaller version of the code started correctly.

Regards,

Terry

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