Open Source FPGA Pi Hat

Over on, [Dave Vandenbout] has posted the CAT board, a Raspberry Pi daughterboard hat that features a Lattice FPGA, 32 MB of RAM, EEPROM, and a few Grove and PMOD connectors. The CAT takes advantage of the open source tool chain available for Lattice including the Python-based MyHDL (although, you could just use Verilog directly, if you prefer) and Icestorm. One interesting point: you can run the tool chain on the Raspberry Pi, resulting in a self-contained and largely portable FPGA development environment.

The design files are actually on Github. You may notice the SATA connectors. However, [Dave] doesn’t know if you could really use SATA drives with them–they are there for general purpose differential I/O.

It is great to have an open source board and tool chain for FPGA development. We’ve talked about the open source Icestorm toolchain before and MyHDL, too.  If you prefer, most of the vendor FPGA tools are free to use for many common devices and uses. The Lattice tools should work just as well with this board, even if it does offend your open source sensibilities.

The video below introduces the CAT board, but be warned: it does contain actual cat pictures. It does not, however, contain any apologies to Dr. Seuss.

14 thoughts on “Open Source FPGA Pi Hat

  1. 17MB “iCE40™ LP/HX/LM Family Handbook” doesnt even mention max speed (gbps) of serdes on those chips …
    xo2 and epc5 max out ~1gbps so not enough for SATA (needs 1.5gbps, no external sata phy chips on the market)

    1. “Have you tried turning off and on again?” Just making light of a tricky question.


      Perhaps using a $3 dollar PATASATA card
      and leveraging OpenCores IP “OCIDEC-1”,ata

      Also Doc from 2013 might be helpful

      I tried a LUT comparison.
      The Biggest iCE40 (this one) is at 7300-7500 luts
      The Old Virtex-4 is at 14000 luts

      Props and Nice project [Dave]. Thank you!

      1. Your LUT comparison also needs to see that Virtex 4 LUTs are 6-input LUTs, while the iCE40 LUTs are 4-input, which is a big deal for both available computing power, and complex operator propagation delay.

        But the Virtex 4, like every Virtex, was a high performance flagship for Xilinx, it didn’t target low-power small-size applications. Even if the Virtex 4 came out approximately 10 years before the iCE40, they’re not meant for the same things.

  2. Still keeping that “everyone loves cat” blight alive? The world is overpopulated, and it will no longer have the capacity to sustain all life. I suggest suicide, to those who snow-balling this blight’s presence alive on the internet, as a contribution to a greater cause that solves both of these issues.

      1. Nah, you remember how you can take your dog to work at Google, well it was only a matter of time before the dogs learnt to use computers and started trolling cat lovers on the interwebs. i.e. You are probably having an argument with a Maltese Terrier.

        1. You’re right. It’s probably my own damn dog who made the post. I don’t know why Buddy wants me to commit suicide: he can’t get to the food without me. I’m the only one with thumbs!

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