I'd designed a USB-JTAG Programmer with FT2232D. I programmed Xilinx spartan3 FPGA 2 times yesterday and everything was perfect. But today when I connect it to my laptop I see the following message: "USB device not recognized"
I saw a post about same problem: "If enumeration is failing, something in the hardware is broken. This could be a damaged chip (make sure you always power the chip completely , so don't let VCCIO be unpowered if you power VCC)."
I've connected the VCCIO of the FT2232D to the VCC of the FPGA board with a jumper, so when the FPGA board is off VCCIO can be unpowered.
Can anyone tell me wheather my chip is damaged or not? Or how I can check it?
Here is my board's schematic:
Note: My laptop has windows XP SP3 media center edition, I've also tested it on win7 64bit but it didn't work.