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USB Superspeed Peripherals

Not applicable



I am working on a USB3 FX3 project and I have the design files ready for FX3 a slave FIFO image and a for FPGA a master bitstream.


I cannot establish communication and test my system. The jumpers are  as follows:


for the Spartan 6 SP601: 

  • FMC JTAG 1-2 shorted -I will use ChipScope- 
  • Also tried with FMC JTAG 2-3 shorted.
  • M0,M1 to OFF
  • J15 shorted
  • GPIO DIP SW8 all ON
  • J16 OPEN

for the fx3 explorer kit

  • J5 open
  • J2 short
  • J3 short

With the devices connected with the interconnect board I power on both devices:


SP601 with the switch ON while connected to a JTAG USB 2.0 for programming bitstream from IMPACT and monitor through ChipScope.


FX3 Explorer Kit just plug in the USB3.0.






The device does not enumerate according to the image or does not enumerate at all! If it is connected to the FPGA-FMC the device enumerates as " Benicia USB Boot Device".  I cannot program it when connected as it does not enumerate. For that reason I programmed FX3 I2C EEPROM with my image and then removed the J4 so to boot from EEPROM instead of USB , and fallback to USB if necessary. It also enumerates as " Benicia USB Boot Device" either programming  through RAM -J4 short- after re-enumeration or through I2CEEPROM boot -J4 open-. The result is that I do not have access to the device endpoints according to my firmware. 


For double checking I downloaded your AN84868 project files and checked the communication with those files but unfortunately with the same results. I need advice.




Thank you

1 Reply



        It looks likes FPGA is driving PMOD pins of FX3 during power ON and putting FX3 in invalid boot up mode. Please try powering up and programming FX3 before connecting to FPGA.