Butterfly Light FPGA Development Board

Butterfly Light FPGA Development Board


Category: Prototype Board

Created: October 22, 2009

Updated: January 27, 2020

Language: Other

Other project properties

Development Status: Stable

WishBone compliant: No

WishBone version: n/a

License: Others



The Butterfly Light is an open source, modular FPGA development board. It is comprised of the USB Cocoon and the Spartan 3E Cocoon which paired together create the Butterfly Light FPGA development board. The Butterfly Light is best suited for developers who prefer to create their own daughterboards instead of utilizing the "Wing" peripheral system. The Butterfly Light exposes the maximum amount of I/O of all available Butterflies. It is also well suited for use with the Logic Analyzer software which implements a 100Mhz, 32 channel Logic Analyzer.


Included Modules



  • USB Cocoon
    • Three independent power rails at 3.3V, 2.5V, and 1.2V.
    • Power supplied by a power connector or USB.
    • High speed two channel USB connection for JTAG and serial communications implemented with FT2232.
    • JTAG and USB connections are protected by high speed buffers.
    • EEPROM memory to store configuration settings for FT2232 USB chip.
    • Open Source design that includes Schematic and Board layouts in Eagle format.
  • Spartan 3E Cocoon
    • 8MHz oscillator that can be used by Xilinx's DCM to generate any required clock speed.
    • VTQFP-100 footprint that supports Xilinx XC3S250E and XC3S500E parts.
    • Bank 0/1 and 2/3 can be jumpered to support 1.2V, 2.5V, or 3.3V.
    • JTAG, Serial, and power connections are routed to the the top header.
    • Power and GPIO are routed to the side headers.
    • Board can be used with Bread Boards if only the outside row of the side headers is populated.
    • Open Source design that includes Schematic and Board layouts in Eagle format.



The Butterfly Platform USB Cocoon and S3E Cocoon are released under the Creative Commons Attribution license. The goal is to support commercial and noncommercial scenarios such as the following:

  • Using the design as the basis for a commercial or non commercial product. In this scenario all that is required is that "Butterfly Platform" and "www.GadgetFactory.net" is credited somewhere on the circuit board and on the webpage. We would like to see the design used as much as possible so we are open to granting licenses without the attribution requirement.
  • Using the design as is or modifying it for a personal or educational project.
  • Manufacturing boards for personal usage.
  • Manufacturing boards for unique commercial products. We highly encourage using the design to derive unique products. What we discourage is manufacturing and selling boards for a product that is not unique from what someone else created. Let the original creator manufacture and sell the boards, unless of course they have no interest in doing so.


Creative Commons License
This work is licensed under a Creative Commons Attribution 3.0 License.