• Joel

A collection of useful facts by Joel Williams. Adelaide denizen. Computer tinkerer. Former terrestrial ecology student of Flinders University. PhD candidate at ANU. Editor for freshmeat.net. Adelaide University Mountain Club member and outdoor enthusiast. Occasional networking go-to guy.

Contact me by email at joel at this domain.

Recent Changes

Search tips

FPGA /

Cheap FPGA Development Boards

What to look for

I bought Avnet's $49 Spartan 3A development board but it was discontinued not long afterward - right about the time when I decided I needed a few dozen more. I've since done some extensive research (thanks, Google!) to find a comparable thrifty thrill.

When choosing a development board, consider what you get with it and what you want to use it for. FPGAs are ideal for use with high speed peripherals, and in general it is much easier to buy a board that contains the part you want, rather than trying to add one on later (and inevitably giving up and upgrading to a more capable board). Examples of things you might want, and are quite difficult to add yourself:

  • Gigabit Ethernet
  • HDMI/DVI
  • PCI/PCI Express
  • External non-serial memory (DDR/Flash etc.)

Things that are relatively easy to add, and are not so much of a big deal to wire up yourself.

  • MMC/SD cards
  • Character (e.g. 16x2) LCDs
  • Anything I2C/SPI and relatively low speed
  • VGA (with low colour depth)

I like having a board with many (at least 8) SPST switches and LEDs, and momentary buttons. While these are easy enough to add yourself, I find that it's better to get a board that has them so that you don't waste valuable user IOs or waste time investigating failures caused by your terrible soldering skills.

Some manufacturers promote a standard form factor for add-ons, notably Digilent with their very wide range of Pmods and the Papilio One's Wings.

If you do wish to connect high speed devices to your FPGA, make sure your board has an interface connector that supports the speeds you'll be using. Look for ground wires interspersed regularly between signal wires, high speed connectors (not just 0.1" headers), PCB trace length equalisation, and impedance control. Few of the cheap boards bother with any of these.

FPGAs can be a bit daunting, so check that the manufacturer provides:

  • Schematic diagram
  • A reference manual, describing all of the on-board peripherals
  • A guide to getting started, if you've never used an FPGA before
  • A reference design that exercises all on-board peripherals.

Reference designs can either be HDL or microcontroller-based, but in recent boards, most manufacturers seem to be moving to the latter. Bear this in mind if you don't have a license for the microcontroller and environment (e.g. Xilinx EDK/SDK is not free), as the code will be difficult to port to HDL.

If you're a beginner, you may benefit from buying a board that has a companion textbook which has been written specifically for the board in mind, and describes each of the peripherals and how to interface with them. Some popular boards have attracted a larger community of users, though this isn't necessarily helpful because most of the other users are beginners. The most popular Xilinx boards are those made by Xilinx (none of them cheap enough to be listed here), Digilent and Avnet. Terasic seem to make the most popular Altera boards.

Boards by FPGA manufacturer

Xilinx

Spartan-6
  • SIOI is an Australian company who sell two basic Spartan-6 boards with TQFP parts, the LX4 and LX9, for the bargain price of $47/57. They contain 32MB of RAM, one LED, and 38 I/Os using a PCIE 4x connector to ensure high speed signal integrity and to make expansion as simple as getting a PCB made.
  • Digilent Nexys 3 ($199, $119 academic) virtually renders the Nexys 2 obsolete. It includes Spartan-6 LX16, a bunch of I/Os, a high-speed VHDCI connector (with matched pairs, but unfortunately it doesn't look like all traces are length matched), 10/100 Ethernet, USB host and USB-RS232, VGA, cellular RAM that sounds suspiciously like it won't work with the MIG, and 16MB of phase-change non-volatile memory. Gives the Atlys a run for its money (if your design is not limited by the smaller FPGA).
  • ZTEK USB FPGA module (99 EUR) has no on-board LEDs or buttons, but contains 64MB of SDRAM and a huge 90 GPIOs in a convenient plug-in module form factor, which is nice for dropping in to a custom carrier board. Unfortunately it doesn't have its own power supply built in, so you need to drop it on to the power supply or experimenter board, and then drop that onto your own board. Still, it's a pretty good price for a Spartan 6, and ZTEK have a very generous discount/rebate program for open source projects that use their module.
  • Avnet Spartan-6 Microboard ($89) appears to be similar to the Arrow BeMicro detailed below. It's designed for embedded processor development and comes with device locked SDK and ChipScope Pro license, which is pretty good as these are quite expensive to buy separately. ChipScope alone is invaluable. I/O capability is pretty rudimentary with only two 8-bit PMOD connectors, but there is a 10/100 Ethernet PHY, four LEDs, two SPST buttons, a 4-way DIP switch, 64 MB SDRAM and 128 Mb flash. The licenses are actually device locked to the XC6SLX9 (of any package), so it might be handy just for those if you were developing your own board with this series.
  • Mesa Electronics has a slightly baffling array of FPGA boards ranging from $79 (Spartan-3, 200K) to $258 (Spartan-6, LX16). One that caught my eye was the 5I25, which is a PCI (not PCI Express) card with a Spartan-6 LX9 for $89.
  • Dan Strother's Spartan-6 BGA test board is not yet a complete, tested product, but it looks very promising and Dan has kindly made the Eagle files available, so it might be a better starting point than the Papilio One for new designs.
Spartan-3
  • Digilent Basys 2 is, if you're a student, only $49, and vastly superior to the Avnet board in all ways other than gate count. The user I/Os are restricted to four PMOD connectors, which is probably enough for many applications, but not for me! It also has PS/2, VGA, switches, LEDs and 7 segment displays.
  • Digilent Nexys 2 ($99 academic) is the most reasonably priced, decently speced Spartan-3E board I've found. The price is especially good if you qualify for the academic discount. Blackbox Consulting had a board in stock and it was in my hands within a couple days. It has eight LEDs and eight SPDT switches, four momentary switches, and 7 segment displays that I haven't bothered with. The main expansion connector is a slightly uncommon one (though it's not expensive and available from Digilent distributors) but it is much better than the Avnet one because it has loads of ground wires, which is good for high speed designs. The "Starter Kit" has a few more peripherals for $70 more but the only thing that really appeals to me is the Ethernet PHY and this is only a 10/100 chip. Citizens demand gigabit!
  • Papilio One seems to be on special for $50 and has the 250K Spartan 3E, or the 500K for $70 (a little rich when the bigger chip is only $7 more, but it's a small company so I can accept it!). The classiest part is that the Eagle board files are freely available, which makes it a great starting place for developing custom FPGA boards, especially since this one has no peripherals at all (other than USB, which looks like it handles serial communications as well as JTAG). It uses yet another custom bitstream uploader tool, but this time it is open source and cross platform.
  • Open Workbench Logic Sniffer ($50) borrows its design from the Papilio One and provides a Spartan XC3S250E, USB, sixteen 5V tolerant buffered inputs, and compatibility with the Papilio One's 'wing' expansion boards. This makes it a slightly better deal, though there's no option for a 500K chip.
  • Enterpoint sell a couple of Spartan-3E boards - the Drigmorn1 (XC3S100E $58, or 500E $85) with parallel port programming cable, RS232, three LEDs and 32 I/Os. A larger version, the Drigmorn2 is $170 and adds SDRAM, more flash, LCD, USB, and switches.
  • XuLA-200 is $55 and fits a 200K Spartan-3A to a very small PCB with USB, a PIC18F, 8 MB of SDRAM, 2 MB of flash, and user IO headers. It could be used as a plug-in module, or since the design is open source (with Eagle files), as the basis for a custom board (as long as it is also open source, as per the license).
  • Gameduino ($53) is an Arduino shield that contains a Spartan-3A 200K. It is intended to be an audio and video coprocessor for Arduino applications, but could be repurposed as a general-purpose FPGA interface board with the Arduino form factor. VGA and audio outputs, with SPI flash.
  • Elbert ($50) is a small board with a Spartan-3A 50K, 1Mbit of SPI flash (half of which can be used for data storage), 8 LEDs, four SPST switches, 8 DIP switches, and 22 accessible I/Os. An on-board PIC18F provides support for programming the flash over USB using a Windows-only configuration utility.

Lattice

  • LatticeXP2 Brevia was on special for $29 at the time of writing, which is a steal. It has now gone back up to $49. There are a couple of caveats - the programmer needs a parallel port, and the USB programming cable, sold separately, costs $149! Without knowing more about FPGAs I struggle to compare across manufacturers, but it's clearly a very low end part with, compared to the XC3S500E in the Digilent board, 176Kb vs 433Kb RAM, 12 vs 20 multipliers, and 5K LUTs vs 9K1. This actually isn't too bad for lower-end applications. Also there aren't many accessible IOs. But still, $29!
  • LatticeECP3 Versa seems to have been recently reduced to $99, which makes it the cheapest PCI-Express development board by far. It also has two gigabit Ethernet ports and high speed serial connectors. It appears that the FPGA device requires a licensed version of the design software, but this is also available for $99 for the first year. Pricing options beyond the first year are not very clear.

Actel

  • Actel IGLOO nano Starter Kit is $99. It has switches and LEDs onboard, USB-serial, a USB programming adaptor, and what looks like plenty of low speed I/O.

Altera

  • Terasic Altera DE0 is $79 (academic price) for something that looks comparable to Digilent's Nexys2, though the connectors aren't suitable for high speed use.
  • Arrow BeMicro is $49 but you'd need the corresponding protoboard to use any of the I/Os. Mainly intended for embedded processor development. There's a short review highlighting some of the other limitations. A newer version is a bit more expensive and has even poorer documentation.
  • KNJN Pluto boards are cheap ($29-$79) and small. No on-board peripherals, so they seem more suited to dropping in to a larger project than as a standalone development tool.
  • ITead Studio BPC009 is notable because it's a $3 bare PCB for a Cyclone II EP2C5T144 ($12). It includes space for an oscillator, voltage regulators, and program memory. The schematic shows a SRAM, but this doesn't seem to be included on the board! Requires a JTAG cable and seems like a very good deal if you already have some experience with Altera parts and have a specific project in mind. It turns out that you can actually buy populated boards from eBay for around $30, such as from this store, or for under $50 with a JTAG programmer. From the same seller, $50 also gets you a Cyclone II EP2C5Q208 with more I/O, 64MB RAM, and 16 MB Flash. Quite nice, really!
  • FTDI Morph-IC-II ($110) combines a Cyclone II with a FT2232H USB interface chip to provide high speed data transfer. It has a total of 80 to 96 I/Os (split between the FPGA and FT2232H, and depending on who you ask) with a 0.1" spacing.
  • Wayengineer sell a large range of very cheap ($28-77) Cyclone II boards from Shenzhen, most with RAM and a variety of I/O including LCDs, 7-segment LEDs, VGA, switches, etc. Again they're great value if you already have some experience with FPGAs, are comfortable reading schematics and don't require any vendor support.

The verdict

None of them! I ended up getting the Digilent Atlys, which has a Spartan-6, HDMI ports, gigabit Ethernet (though getting hold of the datasheet is nearly impossible), and a very nice high speed connector (though getting hold of the right mating connector was a minor challenge). It's a lot more expensive (at $200) than I would have hoped, but the Spartan-6 is significantly better than its predecessor.

Omissions

If you manufacture or know of any other cheap FPGA development boards, please let me know so that I can include them on this list. Review units will be cheerfully accepted! :)

There is a long and comprehensive list of boards at FPGA-FAQ that includes a couple of other cheap options - there are a number of Spartan-3 generation boards that I haven't listed.