• XuLA-50 image 0
  • XuLA-50 image 0
  • XuLA-50 image 1
  • Open-source design
  • XC3S50A FPGA
  • 8 MByte SDRAM
  • 2 Mbit Flash
  • 3.3 & 1.2V regulators
  • 40-pin interface
  • 12 MHz oscillator
  • PIC 18F14K50 micro
  • USB 2.0 port
  • Auxiliary JTAG port
  • Works with the XSTOOLs software
  • Works with XILINX ISE and WebPACK
  • Works with XILINX iMPACT and ChipScope (requires Xilinx JTAG cable)

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Current rating: 3

You're discontinuing the XuLA-50!

That's right! It's dead, finished, finito!

But I need one!

Sorry, can't help you with that. But we do have XuLA-200 boards available at their new, reduced price!

But why discontinue the XuLA-50?

We wanted to reduce the price of the XuLA-200. Now for just a bit more than the XuLA-50, you can get a XuLA-200 board with an FPGA that's four times larger. Once we did that, there didn't seem to be much reason to keep the smaller XuLA-50 around. So we sold off the remaining XuLA-50 boards and simplified our product line.

But I'm one of the guys that bought the XuLA-50!

OK, no problem! Your XuLA-50 still works and we still support it. That's not going to change. It's not like we threw some magical switch and your board turned into a pumpkin.

And if you bought your XuLA-50 board within the past thirty days, then you can always use our "no questions asked" return guarantee and send it back to us for a refund (minus the shipping charges). Then you can use that money to buy a new XuLA-200!

Old Ad Copy

Here's all our old ad copy for the XuLA-50. Everything you read here also applies to the XuLA-200 except that board has a bigger FPGA than the XuLA-50.

"I need a circuit that does X...

... or maybe I just need to add a feature to an existing design."

"Maybe a small micro will do it...

... but there's a signal that's a bit too fast and my micro is a bit too slow."

"Maybe I'll try an FPGA...

... but now I have to add an FPGA and a Flash to hold its configuration bitstream. And I have to figure out how to do in-circuit loading of the Flash. And don't forget the multiple voltage supplies the FPGA needs."

"I'll just use an existing FPGA development board...

... if I can find one small enough. And if I can afford to pay for a bunch of features I don't need. And if I can find a mate for the board's funky high-density I/O connector."

That's why we built the XuLA Boards (pronounced "ZOO-LAH").

They're built to provide just the things you need so you can spend your time adding the features you want. The XuLA Board crams a 50,000-gate FPGA, 8 MByte SDRAM, 2 Mbit Flash, two voltage regulators and a supervisory microcontroller into a 2" x 1" footprint (51 mm x 25 mm for you metric guys). Just plug the XuLA Board into your circuit and connect a USB cable to download and test your design. Once you have your design just the way you want it, you can program it into the Flash and the XuLA Board will load it whenever power is applied. It's really that simple.

It's not perfect — we left that up to you.

We've learned over the past twenty years that we can't anticipate everything you want. And we don't have the resources to design and build every board variation you can think of. So we gave up and made the entire XuLA design open-source. All of it: firmware, bitstreams, schematic, PCB layout, documentation — everything! If you don't like what we built, you can re-design it and build it your way. And you can sell it to others free-and-clear of any royalties. (But you have to open-source your design just like we do.) And as others do this, you may find someone has built a version of XuLA that is perfect for you.

Now what?

Now it's up to you. You can read the FAQ that follows to get more information, and peruse the XuLA Board manual for all the details. Send us an email if you can't find an answer to your question. Then decide if you want to keep forcing your designs into an inflexible system, or if you'd rather take the responsibility to freely build a solution that fits.

It's really that simple.


I ordered a XuLA and all I got was a board. No software? No cable? No fancy box!?

When you order a XuLA, all you get is the board. That's it. Take a look at the related products on the left if you need a software CD, cables, etc. As for the fancy box, well, sorry about that. Think of it as "saving the environment".

What kind of instructions are there for using the XuLA?

We are currently writing and releasing an open-source book that shows how to use the XuLA with the Xilinx ISE WebPACK software to do FPGA designs. There are also some pre-built projects for XuLA.

How does the XuLA get power?

The XuLA can get power through the USB port or directly through one or more of the voltage supply pins on its prototyping header. Or you can use a combination of both methods.

Only a 12 MHz oscillator? That's kind of slow!

That's just the frequency of the clock going into the FPGA. The Spartan3A FPGAs contain Digital Clock Managers (DCMs) that can multiply the frequency of the input clock up to 384 MHz (32x). The DCMs also have dividers so you can generate a wide range of clock frequencies to use in your designs. And you can cascade DCMs together to generate even more frequencies.

How long does it take to download a bitstream?

Fractions of a second if you are downloading a bitstream directly to the FPGA. Downloading into the Flash takes a bit longer, but it's still less than a minute.

Do I have to program the Flash every time I want to test my design?

No. When you are developing your design you will usually download your bitstream directly into the FPGA. You download the bitstream into the Flash after the design is done and you want to remove the USB cable from the board and have the FPGA configure itself from Flash whenever power is applied.

Can I use the Flash for general-purpose data storage?

Not unless you put the XuLA Board into a mode where the SDRAM is disabled. Then the FPGA can access the Flash without interference, but you lose access to the SDRAM.

How do I use the SDRAM in my design?

We provide a controller interface that makes the SDRAM look like a static RAM to your application.

How do I get data in and out of the SDRAM?

The XSTOOLs software provides both command-line and GUI-based programs for transfering data between the PC and the XuLA Board.

How much power does the XuLA Board need?

It's impossible to list a meaningful number for power consumption of the XuLA Board because it's almost entirely dependent upon the circuitry you load into the FPGA. If you utilize 99% of the FPGA's logic and clock it at 200 MHz, you could be looking at 3 A of current. But if you don't load the FPGA at all and just power the board with nothing going on, it draws around 65 mA.

Mainstream FPGAs aren't really meant for low-power applications unless they can be structured so the FPGA is turned on every so often, does a massive amount of computation in a short burst, and then gets powered off until it's needed again.

What does the prototyping header look like?

The prototyping header consists of two rows of 0.1"-spaced pins separated by 0.9".

Can I use Xilinx's iMPACT, ChipScope and EDK tools with this board?

Yes, but you will need a Xilinx or third-party JTAG cable to connect to the XuLA's auxiliary JTAG port.

If I use a XuLA Board in my product, do I have to open-source my entire product?

Not if you just insert a pre-built XuLA Board into a socket in your product. In that case, your product is similar to a software application that uses the XuLA Board like a library of precompiled functions. The application doesn't have to be open-sourced and neither does your product.

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