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From: Tobias Weingartner on 16 Jan 2006 13:14 Brian Drummond wrote: > > FPGA capacities should now be big enough to support a "virtual FPGA" > layer on top of a real FPGA, using only the "public" parts of the > bitstream (e.g BRAM and SRL16 contents, possibly a subset of the > routing) to give a completely open format. Possibly a virtual XC6200, > but probably a coarser grained architecture (mini-Spartan perhaps). > I wonder what size Spartan-3 you would need for a virtual XC6264? At that point, why not create an ASIC... (yeah, price, etc, etc) -- [100~Plax]sb16i0A2172656B63616820636420726568746F6E61207473754A[dZ1!=b]salax
From: Peter Alfke on 16 Jan 2006 13:53 Tobias, this subject has been discussed ad nauseam, in this newsgroup and elsewhere. The reason for the "secrecy" is not so much fear of giving away secrets to a competitor, but rather fear of becoming inundated with support issues. We have about 100,000 designers using our parts, a few dozen of them exploring and abusing subtle aspects could easily bring our support hotline (and this newsgroup) to its knees. Also, the non-open nature of the bitstream provides our customers a certain level of security against reverse-engineering rip-off. Our primary obligation is to remain an innovative and profitable company, to the benefit of our customers, our employees, and our shareholders. Satisfying exotic academic research is fine, as long as it does not conflict with the primary obligation. Just my personal opinion... Peter Alfke
From: Scott & Brenda Burris on 16 Jan 2006 15:32 I'm also one of those rebirth hobbyists. I was a hobbyist up until the mid to late 80's. Probably the most ambitious stuff I tried was a 68020 board with dynamic ram, running at 16Mhz, all on a big wire-wrap board. Back then, the board was stuffed with LSTTL chips. The board was none too reliable -- flex it the wrong way, and something broke. But on a good day, it worked. I tried to make some improvements for reliability. I played with bipolar PALs. Expensive, and I really hated throwing them away when I made a mistake in programming them. I also tried making my own double sided printed circuit boards. Lithographic film, developed in a close bathroom in my apartment. Needless to say, making and drilling these boards was a fiasco. So I just stored all my parts away for 15 years or so. What's changed to get me back into this hobby? Three things. 1) Flash programmable microcontrollers, i.e. PICs and AVRs. None of this burning EPROM business anymore. No wiring up SRAM or DRAM. Just program and go. 2) Low cost schematic/PCB design software and PCB boardhouses. I wouldn't even attempt to make my own boards anymore. And I can get 6 and 8 layer boards, something I'd never attempt as a hobbyist. Woohoo! Soldering those SMD components is a bit of a challenge, especially the PQFP208 packages. Of course there are some interesting things in BGA packages, but I haven't reached the level of craziness to try the toaster over reflow method. 3) FPGA's! I last looked at programmable logic in the bipolar PAL days. I happened to be looking through a Digikey catalog one day and noticed stuff from a company called Xilinx. Hmm, checked their website. Hey, this is pretty neat stuff! And since Digikey (and Xilinx to a limited extent, hint, hint) allow small orders, I can actually get parts. In the 80's, I often had to try going though a rep or Big Distributor, and most wouldn't deal with me at all. So nowdays, I typically design a board with a microcontroller on it, slap a Spartan chip of some sort on it as well, and worry about how to make it work later. Aside from a few early gotchas, like trying to use an input only pin on an FPGA as an output, this has worked very well. I've weaned myself away from schematics for CPLD/FPGA design and taught myself VHDL. To me at least, it's a very different mindset to think in, but it's getting easier as I do more designs. I still struggle with VHDL which looks legal but isn't quite right for synthesis, trying to interpret some obscure message from WebPack. Now I'm looking to do even more. I keep checking to see when the Spartan 3E board is available. I've worked with the Spartan 3 eval board from Digilent, so I'm anxious to see what's next. And then there's the little matter of the ML403 kit Xilinx offers with the Virtex 4 FX and the EDK. As a hobbyist, I'm cringing at the thought of putting $895 into this. At the same time, I'm going, hmm, what could I do with the PowerPC chip or the MicroBlaze? Hmm, no it's too much money.... But I keep thinking about it :-) I know Xilinx doesn't really target people like me, but I keep hoping for a half-price sale or a hobby bundle on the ML403 (no support, no commercial use or you give up your first born, etc). Cheers, Scott slburris(a)earthlink.net In article <1137338637.940229.315040(a)g49g2000cwa.googlegroups.com>, coreyhahn(a)gmail.com says... > Well, I guess I would be one of those "rebirth" hobbyists. I am > younger and just "discovered" the fpga. I was under the impression > that things like this were very expensive, but when I see starter kits > for $150, I had to snatch one up and try it out. For the last 5 months > I have been feverishly programming and learning with Webpack 7.1 > implimenting different ideas on codecs, processor cores, and so on. > Now I that I have a handle on whats available and possible on most > platforms I bought my first dev board a couple of days ago. I can't > wait for sun to open up there sparc cores. So many ideas so little > time!! > > I can't believe I went through my undergraduate education without > trying fpga's out, and my focus on RF and optics was not very close to > VLSI or control. After 5 months though there are a ton of optics > processing problems that can be sped up with fpgas. Like I said, can't > wait to start debugging!! > > So much to do, so little time... > new Hobbyist > >
From: Ray Andraka on 16 Jan 2006 15:49 Tobias Weingartner wrote: > > I happen to disagree. We are all entitled to our opinions of course. > If the vendors would have a well defined format to "compile" to, and > a good library/port for a program to be able to take this format and > then generate a bitstream, that would be a start. Note, I'd want to > have the source available to be so that I could port this last bit of > "technology" to my favourite OS (by choice or necessity). > > I can't believe that these things are anything but simple portable ANSI > C (or some derivative)... > The problem is the bitstream is very tightly tied to the architecture of the FPGA cell. Having a well defined format tightly constrains the FPGA architecture to the one the bitstream format is published for. What that means is that either the format has to change for every fpga variant out there, now and in the future, or the FPGA has to be frozen in order to comply with the bitstream format. There is far more coupling between the bitstream in an FPGA and its hardware than there is between an instruction set and a processor architecture because of the fine granularity of the configuration of the FPGA. In other words, an instruction set in a microprocessor controls relatively few connections between some very complex blocks. The FPGA bit stream controls many many connections between lots of small simple blocks, so if the bitstream format is predefined by a standard there is very little lattitude for evolving the FPGA's structure. I'm not sure I see what the big push for having bitstream access is. I've yet to see a compelling need for it that is not addressed by the existing tools (there is always XDL if you really want to bit bang). The only reason that seems to surface is to allow outside parties to develop their own place and route tools. Frankly, I don't think the complexity of modern FPGAs is such that this type of undertaking can improve on or even compete with the free place and route tools already offered by the FPGA vendors in the timeframe between device introduction and obsolescence. Anyway, for those hadry enough to try, as I said, the XDL tools do give you enough access to every step of the design flow to allow you to play with any step you feel compelled to play with.
From: Rob on 16 Jan 2006 21:56
Hobbyists. Now there's a term you don't often hear amongst the next generation. If the hobbyist is going to make a comeback in this country (US) it is going to take more than a low-cost, high capability FPGA. With the watered down public education serving up a non-challenging, push them through curriculum, what hope is there for technologists in this country over the next few decades? Do you know how many times I've walked into a gas station and encountered a teen who can't carry through on a simple transaction? The youth today aren't--for the most part--go getters: they lack direction, motivation, and personal responsibilty. They are not problem-solvers, they're problem-makers who go though life thinking that somebody is always going to wipe their backside. Give them a kit of parts and ask them to make it work-ha! They might have to read a book! It has been reported that high school graduates are increasingly choosing non-technical fields to major in. The technical fields are too challenging, require too much work, and interfere with the 50hrs/week of playing video games. Where are the Heathkitter's of the next generation? I've ranted long enough........................... "Kevin Morris" <kevin(a)techfocusmedia.com> wrote in message news:1137096913.255199.239090(a)o13g2000cwo.googlegroups.com... > I'm writing a feature article for FPGA Journal (www.fpgajournal.com) > about FPGAs and the re-birth of the electronics hobbyist. My theory is > that electronics as a hobby went through a "dark age" period, maybe > from the early/mid 1970s until recently becuase of the inaccessibility > and cost of designing with state-of-the-art technology. Radio Shack > shifted their focus from 50-in-1 project kits and hobbyist parts to > selling toys, cell-phones, and stereo equipment. > > Now, with the emergence of low-cost, high-capability FPGAs, development > boards, and design software, I see a new age of hobbyist activity > beginning (as often evidenced in this group). > > I'm looking for a few people that would be willing to express views on > this topic for the article. > > I know, Austin will probably post a strong technical argument that > Xilinx FPGAs are uniquely attractive to the hobbyist, somebody from > Altera will send me a Cubic Cyclonium prototyping paperweight (they're > very cool), and Actel and Lattice people will post just to remind us > that they have low-cost kits too, but I'm primarily interested in some > info from real, live, "working" hobbyists. > > Any takers? > |