NEW PROTOTYPE: XC9572XL CPLD development board

Ever get stuck choosing the right logic chip combination or voltage level translator? Give up the hunt and create your own custom logic chip. CPLDs can give you the logic you need, with the pinout you want, while saving board space and board revisions.

The Xilinx XC9500XL family has some of the cheapest and readily-available CPLDs. Inputs are 5volt tolerant, and they can be run from a single 3.3volt supply. This dev board will help you build your first custom logic chip using simple schematic entry, Verilog, or VHDL.

What can you do with a 72 macrocell CPLD? Check out our 32K SRAM logic analyzer core.

Hardware design overview


  • XC9572XL CPLD with 72 macrocells
  • 5volt tolerant inputs
  • On-board 3.3volt power supply for core and pins
  • Selectable 3.3volt or external supply for pins (1.8volt to 3.3volt)
  • LEDs for output
  • Push button for input
  • Populated JTAG header
  • Easy to program with the Bus Pirate
  • Unpopulated oscillator footprint on bottom
  • Pre-programmed with LED inverse toggle demo
  • Open source (CC-BY-SA)

Resource

We’ve been interested in CPLDs and FPGAs for a few months now, and there’s already several CPLD resources on the wiki:

You can get the XC9572XL development board for $15. A CoolRunner-II dev-board is also available for $15.

Have an idea for this dev-board? Share it in the comments and we’ll send you the PCB (while they last).

Join the Conversation

19 Comments

  1. I didn’t realize how fast the 9500’s were. Built in logic and 5v level shifting? Yes please. That said, part of me wishes you had used some of the un-solderable by humans chips so I could actually use a 128 or 256 macrocell 9500 or x2c2 in a project.

    My first cpld project is to add a second high speed i2s serial interface to a dsPIC or XMEGA to make a very simple DSP and do some audio manipulation in software instead of in a full fpga.

    It seems to me that doing custom or unique high speed serial interfaces is a place where cplds shine still.

    1. Thanks for your suggestions, it’s always appreciated. We really struggled with right way to target our CPLD boards. We went with the 44pin version because it’s something many people might feasibly move on to use in an actual project on a DIY PCB. These CPLDs can be had in 1s for ~$2.50, but the bigger ones get really expensive really fast. There’s a couple of current dev-boards for the bigger chips from companies with volumes we can’t compete with. We chose to stay with the niche little chips that nobody seems to make a dev-board for, and offer then as cheap as possible. If this works out we’d definitely consider the bigger chips in a future dev-board.

      1. I always forget you aren’t necessarily buying by the hundreds/thousands :) A large CPLD board may never actually be worth it considering the logic sniffer and the papillo could both probably do the same job with vastly more capability and at a competitive price.

        Now that I think about it more, In reality one of the QFP breakouts & a higher-density CPLD may be the way to go, if one needs that many macrocells.

      2. Oh and also, you’re absolutely right that no-one does small cpld breakouts/dev boards, especially for the older 9500 series. I’ve looked everywhere.

      3. That’s usually our inspiration :) “Why isn’t anyone doing this simple cheap thing?” :) There usually isn’t huge demand, but there is a very small un-served market that keeps a hobby site going.

  2. My apologies if this has been mentioned but the March and April issues of Servo magazine have the start of a series of articles on using Xilinx CPLD’s. The April article is titled Graphical programming of a CPLD and is geared towards the XC9572XL.

      1. Ian, I remember you talking about Lattice cpld’s waaaay back when, that they were super cheap or something. Did you go to xilinx for software reasons, like ISE vs whatever, or were the chips just not as suitable?

      2. I like lattice because the chips are available at Mouser and I like mouser :) Xilinx seems to be more approachable for hobbyists, and there’s more tutorials and demos out there, but alas only available at Digikey.

        I suspect after we’re sufficiently experienced with Xilinx chips we’ll probably make other boards for small Lattice and Altera CPLD too :) We’re not committed to a single vendor.

  3. I used the altera software in my digital 2 course and it was perfectly fine. I recall the pin assignment was absolutely buried somewhere and a few other things were in very obtuse places.

    Altera does still have some large plcc cplds too which is nice but they are 20-30 bucks.

  4. I started to install WebPack ISE, but I stopped as it seems to require 11GB of disk space.
    Am I right or is it just the required space for a full installation?

    1. Thanks Cuagn!

      The download is about 4.6gig, the install…. who knows, it’s a beast of a program :)

      1. Xilinx_ISE_DS_Win_13.1_O.40d.1.1.tar is a 4 171 274 240 bytes file.

        And it requires 11655 MB on disk to be installed!

        The bigest installation I never saw.
        Need to buy a new disk drive!

  5. I would like to buy one, but how can I program it? I don’t have any JTAG programmer.
    In my opiniom a USB interface + PC application would be awesome for this board.

  6. Could you use a random JTAG dongle and OpenOCD for interfacing?

    You can find USB Blasters well under $10 at aliexpress. That would be a nice unholy alliance of Xilinx, Altera and FOSS in one package :)

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