I am a newbie at FPGA. I bought BASYS2 digilent board(Spartan3E). I have background on microcontrollers. C/C++ is no problem for me. But I am having some trouble with FPGA. Actually, not with FPGA but with Compiler and ISE. As you can see in the screenshot below, I configured the FPGA chip.

FPGA Verilog screenshot

This is the implementation code:

module myModule(A, B);
    input wire A;
    output wire B;
    assign B = !A;


And this is the ucf code:

# Onboard LEDs
NET "B" LOC = "M11";

NET "A" LOC = "C11";

As boards technical sheet says, M11 is LED 1 and C11 is BTN 2. So I want LED to flash when I unpress the button. Do you see something wrong with the code? Because it aint working. If the code should have been working, what should I do? Am I skipping something?


As you see I aldready generated programming file and run. So what next?


  • 1
    \$\begingroup\$ The schematic shows C11 as BTN1 not BTN2... \$\endgroup\$
    – user16324
    Commented Dec 25, 2015 at 11:03
  • \$\begingroup\$ How do you mean, "run"? Do you mean you opened Impact and followed the necessary steps? Every thing else is fine \$\endgroup\$
    – johnnymopo
    Commented Dec 25, 2015 at 15:56
  • \$\begingroup\$ As long as your hitting the right button @Brian Drummond \$\endgroup\$
    – johnnymopo
    Commented Dec 25, 2015 at 15:57

2 Answers 2


Go to project->Design Properties and under Project Settings make sure that everything is configured correctly for the BASYS2. Make sure you have the correct family and device selected.

I've attached an image which I believe has the correct settings for your board. Check to make sure yours match!

enter image description here


Make sure you have selected the correct board or the FPGA that is one very common mistake beginners make. Follow the link and download master ucf file for BASYS 2 board edit the UCF file as per your needs.



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