30 Aug
2010
30 Aug
'10
2:43 p.m.
On 8/30/10 3:12 PM, Ethan Dicks wrote:
I don't know where the cutoff point is, but it's big. If you want to
design with a monstrosity of an FPGA that has over a thousand pins, one
or more integrated (not array-implemented) PowerPC CPUs and GigE
controllers, and carries a single-unit price tag in the hundreds of
dollars as "used pull, needs reballing, as-is" on eBay, then the free
WebPACK probably won't do it. ;)
toolchain
(WebPACK) that works very well. It even has "real" Linux
support nowadays.
Excellent. For me, Linux development support is 100% essential. I'm
not likely to bother to get started if I have to set up a new
environment just to play with toys (I'm already set for Arduino and
Makerbot hacking from my CentOS laptop).
The free stuff supports all but the very largest
of
their FPGAs.
Can you be a little more specific? What counts as "the very largest"? I am, in fact, a bit muddled about which Diligent
board would be a
good buy. I see prices between $100 and $200 for boards with various
features, but besides just buying the most expensive board because "of
course" it will have the most extras (attached RAM amount, gate count,
etc), I'm not sure what to get to be able to take advantage of what
appears to be an active pool of Diligent-based projects (I've
encountered two just in the past 10 days).
I have an S3BOARD with the XC3S1000 (1,000,000-gate) chip upgrade.
The board is very "friendly" and has flexible I/O that's easy to deal
with, and they have a line of "expansion" boards that plug onto its
connectors, that give you things like solder-type and solderless
breadboard areas, some analog I/O, etc etc. I think it's the best bang
for the buck. It has plenty of onboard goodies (RAM, PS/2 kbd, VGA,
etc), without being "too much" to get in the way of actually using the
FPGA's pins for your own stuff.
This is it:
http://digilentinc.com/Products/Detail.cfm?Prod=S3BOARD
It comes with extensive documentation including schematics, and lots
of other stuff like "here's how you generate a VGA signal" and
"here's
how you interface to a PS/2 keyboard, and here are all the PS/2 key
press/release codes".
The current price is $109, plus $50 for the million-gate chip upgrade.
I have the board manual handy in PDF format; let me know if you'd
like a copy to study.
I'd been out of the FPGA world for a couple of years, but got back
into it early this year. The new Linux-based WebPACK software is nice,
but I was annoyed to discover that my very expensive USB JTAG module was
been desupported while I was away. Fortunately, new ones are nowhere
near as expensive as they used to be.
I've seen gate counts like 100K, 250K, 500K, and
I've seen model
numbers like the "Spartan 3E-1600" and am not quite sure what maps to
what. Could someone who owns a Diligent board provide any information
about variations from model to model and what features are "must
haves"?
As far as "must haves", well, that depends on what you want to do. ;)
Personally I like PS/2 keyboard interfaces and VGA connectors with
attached DAC networks. Attached SRAM is handy.
-Dave
--
Dave McGuire
Port Charlotte, FL