Barriers to designing with FPGAs?

I haven't had any familiarity with FPGAs.

This's partly because, apparently the software to use them effectively is all expensive and proprietary; there's no (decent?) open source, free software to get started with them.

Also I haven't seen any examples of using them so I'm not sure how relevant they are to me and projects I do or want to do to consider them.

Hello Christopher,

Thanks for replying. You are not alone, lots of people think the software is expensive and if you want to target high end FPGAs it can be however, you can get software which will allow you to target complex FPGAs for free. Altera, Xilinx and Lattice all provide free software to eliminate this barrier.

Your second comment is also very common, because FPGAs are so flexible it can be difficult to decide what examples to create. I am looking to load some content in the next few weeks which will at least start people off in their journey in using FPGAs.

cheers

Simon

Altera appear to have Quartus, which costs money?

Xilinix appears to require licensing, there's some comment on a free version or evanulation but it's not clear what the restrictions or limits are on that.

Lattice does appear to have a free license, but it's not clear what restrictions are on that, aside from locking it down to your MAC address

I'm assuming that across these licenses you wouldn't be able to use it beyond for personal use. Looking into the details were all behind login pages, which currently stopped me looking into it further.

Altera appear to have Quartus, which costs money?

Xilinix appears to require licensing, there's some comment on a free version or evanulation but it's not clear what the restrictions or limits are on that.

Lattice does appear to have a free license, but it's not clear what restrictions are on that, aside from locking it down to your MAC address

I'm assuming that across these licenses you wouldn't be able to use it beyond for personal use. Looking into the details were all behind login pages, which currently stopped me looking into it further.

If you want to play FPGA you'll need to get over your logging in inhibitions

There is free (as in beer) software and you can do quite  a lot with it.

Once you start paying for software it does get quite expensive especially if you buy from a silicon independent source. But for starting there is no need at all to do this.

There are reasons why the software is the way it is - in the beginning Xilinx offered the first FPGAs, one with 64 look up tables (LUTs) and one with 100  - now we have devices with 10E6 LUTs. The software was paid for and I may mis-remember but I think at that time  (20+ years ago) was a few thousand pounds. When Actel entered the market their software was up at the £20k level. As time passed it became apparent that 1) the software was a major part of the product and 2) very few customers were prepared to pay for it up front.

This resulted in the rather odd business model for FPGA companies where they give away or sell for peanuts a software product that you would normally expect to pay very serious money for (comparing with similar complexity software - at least £10k).

I get the feeling that no one much likes this situation but it's where we are and it isn't going to change quickly unless some one has a really game changing new idea.

John B (who will probably chip in himself) thinks that if the Silicon companies would open up a bit and allow third parties including open source people ready access to the necessary info then open source tools could emerge that would change the game. So far no one has done that.

If you could indicate the kind of projects you do I'd be happy to pitch an FPGA at you (or not if I don't think one would be any use.)

FPGAs can do amazing stuff but it takes a lot longer to write the 'code'  (really should be 'design the logic') than software based people expect.

(I'm away for the next few days so I won't respond till Monday - if anyone replies.)

MK

Christopher Stanton wrote:

 

Altera appear to have Quartus, which costs money?

Xilinix appears to require licensing, there's some comment on a free version or evanulation but it's not clear what the restrictions or limits are on that.

Lattice does appear to have a free license, but it's not clear what restrictions are on that, aside from locking it down to your MAC address

 

I'm assuming that across these licenses you wouldn't be able to use it beyond for personal use. Looking into the details were all behind login pages, which currently stopped me looking into it further.

Xilinx, Altera, Lattice, and Actel (now part of MicroSemi) all have free-as-in-beer (FaiB) software for their smaller parts.  If you want to use their chips that cost $1000 and up you'll have to pay for the software, but for any chip you'd want to use for learning you can use the FaiB version.  The FaiB version may not have all the tools that the pay version has.  For example, Xilinx ChipScope is not available in ISE WebPack.  Also, you don't get any support with the FaiB tools other than on-line forums.

You do need to register to download the software.  I think this is mostly to ensure that you have "signed" the end-user license agreement (EULA).  This is standard with any software that's not Free-as-in-Freedom or Free (Libre) Open-Source Software (FLOSS).

I've done all my FPGA work for the last 15 years or more using the FaiB versions.  There's no restriction on using the FaiB software for personal, educational, not-for-profit, or commercial applications.  It's FaiB to remove a barrier to buying FPGA silicon, which is how an FPGA vendor makes money and pays for tool development.

I don't have time right now to go into my "The FPGA is the poster-boy for Free-as-in-Freedom Software" speech.  I'll come back and give you some links.  For now, take a look at my 'blog Flavia: the Free Logic Array.

I'll take a crack at answering "Why would I be interested in designing an FPGA"?  Very simple:

Have you ever wanted a custom digital chip for a project, but didn't have $1 million lying around to pay for fabricating it?   Well, an FPGA lets you do it for tens of dollars.

Wow.  It still blows my mind.  Wow.