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