XESS introduces their new XuLA-200 breakout board. The XuLA Board packs a 200,000-gate FPGA and a supervisory microcontroller into a 2″ x 1″ footprint (51 mm x 25 mm). XESS is committed to a completely open source design for this board which features a Xilinx XC3S200A Spartan 3A FPGA with 8 MByte SDRAM, 2 Mbit Flash, 3.3 & 1.2V regulators, a 12 MHz oscillator and 40-pin interface. Alongside the FPGA is a PIC 18F14K50 micro, USB 2.0 port and auxiliary JTAG port.
The board works with the XSTOOLs software, XILINX ISE and WebPACK, iMPACT and ChipScope (requires Xilinx JTAG cable).
Check out the XuLA-200 Manual.
I think this is really cool design. I’m not sure why they didn’t use one-FPGA bigger (the 250), but still a great package (on-board SDRAM!) and 100% open source. I grabbed the files, but they look to be 4-layers and the free eagle won’t show them.
Thanks for your comments, Ian. We couldn’t use the XC3S250E FPGA because it has four fewer I/O pins than the XC3S200A, and I/O pins are already in short supply as it is. (The 200A also allows us to ditch the 2.5V supply and just use 3.3V and 1.2V.)
I like the small form factor, it’s perfect for breadboarding, but the pricing is pretty darn expensive in my opinion.
I bet the 4-layer board really drives the price up. It is pretty expensive, especially without an on-board JTAG debugger like most similar dev-board have.
Ian, perhaps I’ve misunderstood your point, but I don’t think there is a need for an on-board JTAG debugger for this board. The PIC micro is just a supervisory controller for the FPGA (power-up, initialization, USB interface, etc.); it really isn’t intended for use as a separate firmware development platform (although it is reprogrammable) where on-board debugging would be useful.
Jan, we’ll be happy to sell you a bare board for $5 if you want to build one up yourself. Contact me if you’re interested in doing that.
Do you still have bare boards to sell?.
You should advertize this on your site, I ordered boards myself and it is not only expensive, but takes long time to manufacture (at bearable price). I would buy several for $5 myself, and many hobbyist would.
BTW, how do you program PIC for this board, before soldering or through USB socket already on-board?
Its quite nice in this compact form factor. There are some limitations in this design though.
Looking at the block diagram and the manual, you’ll see that the PIC can only talk to the FPGA with JTAG. Its a shame that it doesn’t include some basic serial support.
Another thing is that its got a 8Mx16 RAM but only 4Mx16 of it is accessible. “A single FPGA pin drives both bank-select inputs (BS0 and BS1). This reduces the accessible region of the SDRAM by half to 4M x 16.”. They’re only advertising 8MB anyway so I guess its not that much of a problem.
The final limitation which they do mention in the FAQ is that due to lack of pins, you can’t access the flash and the SDRAM at the same time. Loading the configuration from the flash is fine and you can use the SDRAM after thats done but your FPGA core can’t access flash. If you want access to the flash for something more than just configuration then you must disable the SDRAM.
Something in a small form factor with a PIC/whatever doing USB JTAG + serial, a FPGA, some SDRAM and a MicroSD slot to load configuration + store data would be very nice. Oh and its got to be cheap ;) Ah well. I can dream…
Tiersten, you can get access to the RX pin of the PIC UART through the ANALOG-IO1 pin of the XuLA board. And you can pipe the TX pin through the FPGA so it appears on any of the channel I/O pins (but you lose access to the SDRAM when you do this). However, you’re probably better off using the USB to communicate with the PIC instead of a serial link. Not that you want to use the PIC for firmware development; it’s primarily a supervisory processor.
Most of the other problems you mention will go away with the use of a larger FPGA in a 256-pin BGA. The microSD socket does necessitate a “bulge” at the end of the PCB to get enough room.
The Winbond W25X20BV (2M-bit) SPI flash is not listed in Xilinx Impact family support list.
http://www.xilinx.com/support/documentation/sw_manuals/xilinx14_4/pim_r_supported_spi_bpi_proms.htm
Does this mean I can only program the SPI flash (*.mcs) using XSTools and NOT Impact ?
Hi Dave,
I was hoping to use the Xula 2 board without buying a seperate Jtag unit, but it appears this cannot be done. I am only starting with VHDL. My PC has no parallel port either.
Your next step is to select the parallel port that your XS Board is connected to from the
port pulldown list. GXSTEST starts with parallel port LPT1 as the default, but you can also
select LPT2 or LPT3 depending upon the configuration of your PC.
The Xilinx JTAG adapter is very expensive. Could you recommend a cheaper one please?
Thank you
Johan Smit
Hi does this board use the fpga configuring methods explained in this appnote http://www.xilinx.com/support/documentation/application_notes/xapp502.pdf