Nexys2 - Configure Via USB

The Nexys2 is a low-cost FPGA development board from Digilent. It features a Xilinx Spartan-3E FPGA (500K or 1200K gate version), 16 MByte Flash/SDRAM, USB and an RS232.

The board can be powered via USB, which makes it quite convenient to use. The board can be configured in two different ways:

1.) Using a Xilinx Platform Cable

- attach cable (separade leads) to J5.
- pins 1 to 6: TMS, TDI, TDO, TCK, GND, VREF

Using the platform cable provides convenient access to the FPGA + attached SPI flash as well as the platform flash (PROM) using the impact tool from the Xilinx suite.

2.) Configuring via USB

... which does not require the expensive platform cable!

In case you run Windows, just download the Digilent Adept tool from the digilent website.

In case you run Linux you are fine thanks to the guy who wrote a nice tool called nexys2prog. It is fairly straight forward to set it up and works like a charm (example for Ubuntu / Debian):

apt-get install fxload
apt-get install libftdi
download UrJTAG and install it via:
./configure
make
make install

Now you should be ready to run the nexys2prog configuration script

nexys2prog myfile.bit

It will detect and configure the Nexys2 board when it is connected to the USB port. In order to do so, custom firmware is loaded into the board's USB controller. Unplug and replug the board in order to restore the original configuration, which is required to use Digilent Adept.