It's the Same Size, Only Bigger!

Well, I finally finished testing the XuLA2 prototype a few days ago and released the PCB to manufacturing. When I layed-out the prototype, I butted the microSD socket right up against the FPGA in order to keep the board at 2" x 1". I knew that wasn't going to fly for final production, but I wanted to get it done quick so I could find the other gotchas that typically occur when I move to using a different chip (in this case, the Spartan-6 FPGA).

It turns out there was a gotcha involving the strength of the Spartan-6 pullup resistors, but that was easily resolved once it was finally found. So the only change needed on the board was to find a way to fit the socket on there. I accomplished that by rotating it 90 degrees. While I don't think that looks as good, it was the only way I could find that didn't require making the board a little bit larger than the original XuLA. Here's what the final 4 x 2 array I sent to manufacturing looks like:

I should have the PCBs back around mid-August, meaning the XuLA2 should be available around the beginning of September.

So the XuLA2 ended up the same size as the XuLA, but with 6x the logic density, 3x more internal memory, 4x  larger SDRAM, and a socket for holding a multi-GB memory card. You can find a lot more information on the XuLA2 product page, including the preliminary manual.

It's nice to be wrapping up the XuLA2. Now it's back to porting the XSTOOLs to Python and starting on XuLA3.

Taxonomy upgrade extras:

Comments

Congratulations! Besides being bigger it fixes two of my peeves with the original: awkward pin sharing and lack of SDRAM byte-enables. This will be interesting.
Cheers
Tommy

Thanks, Tommy. It was a long road to get here. Hopefully some people will find it useful.

Sure it's usefull ;)
Put one of side for me for the day they get available please.
Are the Xula200 example still valid for this board or are you
made them all new ?
Cheers.
Fabrice.
 

Fabrice, you'll have to recompile the examples for the Spartan-6 FPGA. The pin assignments are all different. And there are more control lines for the SDRAM, but you shouldn't notice that too much if you're using the SDRAM controller.
The XuLA2 is pin compatible with the XuLA, so you can plug in either one.

Can we Order them and wait till they are available ?
on the 'Product Description' from the XuLA2-LX25 you write :
XuLA Board with 200-thousand gate Spartan3A FPGA ;) ... i think it have a little more ... he he he ...
Cheers.
Fabrice.
 

Thanks, Fabrice! I fixed that error.

Awesome.  now we just need you to write the "microSD! Now What?"  chapter.  no good deed goes unpunished!

I'm wondering what kind of deed actually goes unpunished!