# FPGA recommendations

S

#### [email protected]

Jan 1, 1970
0
Hello all,

I'm looking for an FPGA platform to produce some low-volume designs on,
and I would like to hear the group's suggestions on manufacturers.

What I am most concerned about is the flexibility and functionality of
the programming tools. In other words, whether they're crippled unless
I pay thousands of dollars for the "full version." I won't be selling
thousands of units, so I can't consider the software an investment. I
don't mind paying a reasonable amount for a compiler, but I am not in
the same market as Linksys and I can't afford what they pay for
software.

I am currently using Altera flex0k's and quartus, which is free but has
some fairly minor limitations. I can more or less live with the
restrictions as they more or less force me to buy a larger chip than is
necessary but still do basically anything. However, they could pull the
rug under me at any moment by not licensing the free compiler (it
requires a new license file periodically.) Is there a better option? I
recently discovered that Atmel has a CPLD/FPGA line; does anyone have
experience with it?

S

#### Spehro Pefhany

Jan 1, 1970
0
Hello all,

I'm looking for an FPGA platform to produce some low-volume designs on,
and I would like to hear the group's suggestions on manufacturers.

What I am most concerned about is the flexibility and functionality of
the programming tools. In other words, whether they're crippled unless
I pay thousands of dollars for the "full version." I won't be selling
thousands of units, so I can't consider the software an investment. I
don't mind paying a reasonable amount for a compiler, but I am not in
the same market as Linksys and I can't afford what they pay for
software.

I am currently using Altera flex0k's and quartus, which is free but has
some fairly minor limitations. I can more or less live with the
restrictions as they more or less force me to buy a larger chip than is
necessary but still do basically anything. However, they could pull the
rug under me at any moment by not licensing the free compiler (it
requires a new license file periodically.) Is there a better option? I
recently discovered that Atmel has a CPLD/FPGA line; does anyone have
experience with it?

Look at Xilinx. They seem to be agressively pursuing your (our)
in until you hit the really big expensive parts. The Mentor ModelSim
requires a node-locked license, but it's free as well (and I think
Xilinx is working on their own simulation package). Apparently the
Mentor s/w deliberately runs slower than the $$package, though, once you exceed 10,000 lines of code). Also, at least according to my FAE, they deliberately don't go overboard on protecting their 'evaluation' software (you can de/re-install to get another 'evaluation', he says) because they want to sell silicon. They have soft processor cores available (8-bit is free in object code) and some of their huge 90nm arrays have a handful of PowerPCs littering the corners of the chip in case you need a processor. I've found the S/W pretty much bug-free (perhaps not quirk-free) so far, though it will tax the speed of the best computer you can buy. I have not used Altera's software, so I can't compare. http://www.xilinx.com/xlnx/xebiz/de...Design+Tools&iLanguageID=1&key=webpack_faq#1b Best regards, Spehro Pefhany D #### David Brown Jan 1, 1970 0 Spehro said: Look at Xilinx. They seem to be agressively pursuing your (our) market. You can download the software, IIRC the limitations don't kick in until you hit the really big expensive parts. The Mentor ModelSim requires a node-locked license, but it's free as well (and I think Xilinx is working on their own simulation package). Apparently the Mentor s/w deliberately runs slower than the$$ package, though, once
you exceed 10,000 lines of code).

Altera is similar, except that they already have simulation software
(and have had for a long while, I believe). I've never bothered with
the free ModelSim for Altera Quartus.

All major FPGA/CPLD players use node-locking on their tools, and all
(that I know of) have some sort of time limitation on their free
versions. Altera paid-for licenses are permanent - I'd guess the same
applies to Xilinx.

Altera and Xilinx are by far the biggest players in the fpga market -
there are others in the CPLD line (Lattice has some nice parts). But
for fpgas, you are best with A or X unless you want a more specialist part.
Also, at least according to my FAE, they deliberately don't go
overboard on protecting their 'evaluation' software (you can
de/re-install to get another 'evaluation', he says) because they want
to sell silicon. They have soft processor cores available (8-bit is
free in object code) and some of their huge 90nm arrays have a handful
of PowerPCs littering the corners of the chip in case you need a
processor.

I've found the S/W pretty much bug-free (perhaps not quirk-free) so
far, though it will tax the speed of the best computer you can buy. I
have not used Altera's software, so I can't compare.

http://www.xilinx.com/xlnx/xebiz/de...Design+Tools&iLanguageID=1&key=webpack_faq#1b

I haven't done more than play around with X's software, and that was a
while ago. But it struck me that X tools were made from a collection of
different tools bundled together, while A tools were much more
integrated. This made the Altera tools more consistent - I think they
are a definite selling point for Altera.

Both A and X have soft processors, available under similar terms and
with similar functionalities, although I personally think the Altera
soft processor is a better system. Altera have effectively dropped
their hard processor core line, having concluded that in virtually all
cases, you are better with either a flexible soft processor or an
external processor. Xilinx PPC parts are well publicised, but are a
very small market.

The main difference between A and X, however, lies in their reputation
for availability. I have never had to get hold of Xilinx parts, so I
can't speak from personal experience, but the appearance seems to be
that when Altera announce availability of a new part, you can order it.
When Xilinx announces availability of a new part, you can get samples
in about a year or so. If you look at the comp.arch.fpga newsgroup, you
asking when and where they can be bought.

Of course, opinions vary wildly, and depend on many factors (your target
applications, the quality of your distributors, personal experience).
But either way, drop the old Flex devices and go for Cyclone II /
Spartan 3 (or Stratix II / Virtex for the high end) and the latest
version of the tools.

S

#### Spehro Pefhany

Jan 1, 1970
0
On 6 Dec 2005 16:08:58 +0200, the renowned David Brown

All major FPGA/CPLD players use node-locking on their tools, and all
(that I know of) have some sort of time limitation on their free
versions. Altera paid-for licenses are permanent - I'd guess the same
applies to Xilinx.

The Xilinx free Webpack software is not node locked, only Modelsim,
and it doesn't 'call home'. I think it's permanent, but I've not
verified this. The stuff I downloaded a couple of years ago still
worked a few weeks ago, even Modelsim.
Altera and Xilinx are by far the biggest players in the fpga market -
there are others in the CPLD line (Lattice has some nice parts). But
for fpgas, you are best with A or X unless you want a more specialist part.

That was my conclusion.

Of course, opinions vary wildly, and depend on many factors (your target
applications, the quality of your distributors, personal experience).
But either way, drop the old Flex devices and go for Cyclone II /
Spartan 3 (or Stratix II / Virtex for the high end) and the latest
version of the tools.

My FAE said that the best Xilinx deal was typically with the latest
silicon.

They seem to be following certain aspects of Microchip's business
model-- leaving higher prices on old silicon, inexpensive development
tools widely distributed, etc. Of course FPGAs use close to
state-of-the art silicon processes so they can't go with surplus
memory fabs for production-- they are fabless. Don't know much about
Altera. Similar?

Best regards,
Spehro Pefhany

D

#### David Brown

Jan 1, 1970
0
Spehro said:
On 6 Dec 2005 16:08:58 +0200, the renowned David Brown

The Xilinx free Webpack software is not node locked, only Modelsim,
and it doesn't 'call home'. I think it's permanent, but I've not
verified this. The stuff I downloaded a couple of years ago still
worked a few weeks ago, even Modelsim.

That was my conclusion.

My FAE said that the best Xilinx deal was typically with the latest
silicon.

They seem to be following certain aspects of Microchip's business
model-- leaving higher prices on old silicon, inexpensive development
tools widely distributed, etc. Of course FPGAs use close to
state-of-the art silicon processes so they can't go with surplus
memory fabs for production-- they are fabless. Don't know much about
Altera. Similar?

Very similar. Altera and Xilinx decisions are often based on small
details or personal preferences or experience - the differences are
small. I just posted so that the OP wouldn't think there was something
special about Xilinx parts or tools, and to give some balance.

K

#### Keith Williams

Jan 1, 1970
0
Very similar. Altera and Xilinx decisions are often based on small
details or personal preferences or experience - the differences are
small. I just posted so that the OP wouldn't think there was something
special about Xilinx parts or tools, and to give some balance.

IME, Xilinx has better I/O. Of course, they bought and killed the
company who's part I was using, for their I/O IP. The project was
scrapped and I had to do a complete redesign with 'X'. A year and
a complete board design gone, poof. I took another year to get
Virtex-E parts (with the I/O I needed).

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