[rc5] FPGAs, why manufacturers don't want you to have them, w
hy you want them
RFowler at ins-server.jpl.nasa.gov
Sun Nov 9 12:44:04 EST 1997
> From: Darxus[SMTP:darxus at Op.Net]
> Reply To: rc5 at llamas.net
> Sent: Sunday, November 09, 1997 10:08
> To: rc5 at llamas.net
> Subject: [rc5] FPGAs, why manufacturers don't want you to have
> them, why you want them
> FPGA technology is fast and cheap. The cost of an AT&T ORCA chip
> that can test 30 million DES keys per second is $200. This is
> times faster than a PC at about one-tenth the cost! FPGAs are
> widely available and, mounted on cards, can be installed in
> standard PCs just like sound cards, modems, or extra memory.
> FPGAs are cool because they have speeds near that of burnt in ASIC
> (Application Specific Integrated Circuit) chips (Pentiums, sound
> all those kinda things are ASICs) -- and unlike ASICs, FPGAs can be
> reprogrammed to do lots of different things, like 3D graphics
> acceleration, MPEG, etc.... and they don't have the initial startup
> of ASICs which costs 10's of thousands of $$s to burn the first chip
> In the #RC5 (EFNet) IRC channel a copule days ago somebody made a
> similar to "there has got to be *some* reason these things aren't more
> common" -- in response to me mentioning some of the advantages of
> my response was yeah, there's a reason that chip manufacturers don't
> FPGAs. the reason is that they can make lots more money of us by
> us un-programable ASICs that have only one function. the companies
> are currently selling cards with ASICs will make no money off of the
> of FPGAs, since companies that have been developing FPGAs for a long
> have a great lead on this technology (like Xilinx, since, I believe,
> and if they can sell you 10 different chips to do 10 different things,
> the hell would they want to sell you programs to do 10 different
> things to
> be loaded onto a chip made and sold by another company ??
> You sound like a conspericy freak with this you know.
Have you ever actually designed hardware?
Economics questions for you:
How many $200 ASICs can you put on a motherboard that wholesales for
On a sound card that wholesales for $40?
> The reason to use ASICs is that while the NRE (NonRecuring
> Engineering) cost is large the per-part cost is a LOT less.
> There is also a delay for setup and manufature so you don't get the
> parts for anywhere from 10 to 60 days after you send in the design.
> That $200 Xilinx part can be replaced with a $1.25 ASIC. The gotcha
> is the ASIC cost $20,000 for the first chip, and if you have a bug you
> can't fix it. You trash that production run and pay the $20,000 setup
> charge again.
> You use FPGAs for prototype and small lot production, then when you
> have the design validated you recomple your design for an ASIC and
> send it off to the fab house.
> Compaq is a clasic example. On most new Laptops they use Actel FPGAs
> for the chipset, start shipping the laptops, fix any bugs then order
> the ASICs and switch the laptops to the ASICs when they get them 3
> months after they started shipping that model computer.
The break even point is that after you have validated your design
(either by simulation or prototype testing) when does
X * 200 = 20,000 + X * 1.25
Solving for X gives 100.63.
This means if you are planing on making more than 100 items, it would be
cheaper to use ASICs than FPGAs.
On the down side, if you only want 10, with FPGAs that is $2,000 and
with ASICs that is $20,012.5
Xilinx makes parts that require ram or EPROM to store the logic, and
then download it on power up.
This is good for prototypes (easy to change), but bad for shipping
product (anyone can steal your design), if anything happens to the EPROM
you are SOL.
Actel makes 'anti-fuse' logic. You burn the design into the part (once)
and it can't be read back out. This is good for production parts with
validated designs i.e. the first 3 months of production while you wait
to get the ASICs you ordered.
http://www.actel.com/products/systems/designer.html for how to make FPGA
They give away 'lite' design software, and sell parts with built-in PCI
interfaces so you can make custom cards.
You also need a programmer (somewhere between $1,200 and $30,000
depending on what you want to do).
I don't have a price list handy, but I was buying mine from
29 A Technology Drive, Suite 100
Irvine, CA 92618
Tel: (714) 789-9953
Fax: (714) 789-9960
This stuff isn't a hidden industry secret. You just have to talk to
electrical engineers instead of programmers.
Even though you 'program' the logic in VHDL and 'compile' the binary
> web pages with FPGA info:
> RC5 on FPGAs (by barrel)
> weaknesses of strong crypto
> complete FPGA developement kits from Associated Pro:
> a book on Logic Design (in HTML), recommended by barrel (our RC5 FPGA
> online FPGA tutorial from Associated Pro (based on their x84 thing)
> FPGA vendors:
> misc. FPGA pages:
> I am aware that there are a good number of other people who are
> in this technology, and I believe that we would all benifit greatly
> an fpga at llamas.net mailing list, but I have been unable to find out
> who to
> contact on this matter...
> Sun Nov 9 13:08:20 EST 1997
> ***PGP fingerprint = D5 EB F8 E7 64 55 CF 91 C2 4F E0 4D 18 B6 7C
> darxus at op.net / http://www.op.net/~darxus
> "You shall know the truth, and it shall make you odd."
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