[sdiy] FPGAs

[ASSI]

On Friday 28 January 2011, Matthew Smith wrote:
> 1) Development environment must work under Linux. Preferably *any* Linux
> (I run 64 bit Debian Lenny on all my machines) but I can always run a
> virtual machine under VirtualBox, if necessary.

Both the "A" and the "X" company give you free tools that run on Linux and 
don't care which of the "V" language you're using.  You'll have to register 
with them and download a _big_ installer.  You're mostly on your own when it 
comes to problems, but I've just been through installing ISE WebPack on my 
not-officially-supported Linux box and it all works much better than I 
remember from the officially supported SunOS port from a few (ahem... maybe 
many?) years ago...

http://stromeko.net/FPGA.html#ISE-Notes

It's a shame that Avnet discontinued the S3A-Eval-Kit, at $50 there wasn't 
much you could do wrong and the feature set was just right to get started 
without having to invest too much into peripherals.  

> Next cost issue is a programmer. I'm rather hoping that this is
> something that I can build myself, assuming I can find the appropriate
> application note giving the spec. (Based on my experience of
> microcontrollers.)

So far I've escaped the need for a JTAG programmer, there are plenty of 
boards and modules that have a built-in programmer running connecting to 
USB.  If you still have a parallel port, you'll find schematics on how to 
make a JTAG programming cable for those.  Make sure that the programmer also 
works on Linux, though - support there can be somewhat scarce.

> 3) Physical device. Here's the crunch - I've got to be able to solder
> this thing to a hand-made board. Even if I get a board made by Futurlec,
> BGAs are *out*. I reckon I can solder a 144 pin QFP, but think that
> would be about my limit. I don't actually *need* lots of IO pins - so
> where's the 40-pin DIP version, guys? ;-)

You don't really need to be able to solder the FPGA onto your board if the 
FPGA already is on a module with a suitable form factor, like this:

http://www.trenz-electronic.de/products/fpga-boards/oho-elektronik.html
http://shop.trenz-
electronic.de/catalog/product_info.php?products_id=640&language=en

There are many similar modules, but you will have to find a source that 
sells at reasonable prices to hobbyists.  It saves you the multi-layer 
boards the hassle with the power supplies and usually provides an easy way 
for programming, too.  More time to play with your application.


Achim.
-- 
+<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+

Waldorf MIDI Implementation & additional documentation:
http://Synth.Stromeko.net/Downloads.html#WaldorfDocs