I am very impressed. I was reading about Antti's incredibly tiny FPGA project board and saw a mention of a FOSS FPGA toolchain. Not just the compiler, but the entire bitstream generation! http://hackaday.com/2015/07/03/hackaday-prize-entry-they-make-fpgas-that-small/ Several people have built on each other's work to provide "a fully open source Verilog to bitstream development tool chain for the Lattice iCE40LP with support for more devices in the works." http://hackaday.com/2015/05/29/an-open-source-toolchain-for-ice40-fpgas/ https://github.com/cseed/arachne-pnr I haven't tried any of it yet, but I am very impressed that they are reverse engineering the devices so that they can generate bit streams and not rely on the vendor. -- Rick
Finally! A Completely Open Complete FPGA Toolchain
Started by ●July 27, 2015
Reply by ●July 27, 20152015-07-27
On 7/27/2015 12:34 PM, rickman wrote:> I am very impressed. I was reading about Antti's incredibly tiny FPGA > project board and saw a mention of a FOSS FPGA toolchain. Not just the > compiler, but the entire bitstream generation! > > http://hackaday.com/2015/07/03/hackaday-prize-entry-they-make-fpgas-that-small/ > > > Several people have built on each other's work to provide "a fully open > source Verilog to bitstream development tool chain for the Lattice > iCE40LP with support for more devices in the works." > > http://hackaday.com/2015/05/29/an-open-source-toolchain-for-ice40-fpgas/ > > https://github.com/cseed/arachne-pnr > > I haven't tried any of it yet, but I am very impressed that they are > reverse engineering the devices so that they can generate bit streams > and not rely on the vendor.I found another link relating to the tools called "IceStorm". http://www.clifford.at/icestorm/ -- Rick
Reply by ●July 27, 20152015-07-27
On Mon, 27 Jul 2015 12:34:21 -0400, rickman wrote:> I am very impressed. I was reading about Antti's incredibly tiny FPGA > project board and saw a mention of a FOSS FPGA toolchain. Not just the > compiler, but the entire bitstream generation! > > http://hackaday.com/2015/07/03/hackaday-prize-entry-they-make-fpgas-that-small/> > Several people have built on each other's work to provide "a fully open > source Verilog to bitstream development tool chain for the Lattice > iCE40LP with support for more devices in the works." > > http://hackaday.com/2015/05/29/an-open-source-toolchain-for-ice40-fpgas/ > > https://github.com/cseed/arachne-pnr > > I haven't tried any of it yet, but I am very impressed that they are > reverse engineering the devices so that they can generate bit streams > and not rely on the vendor.Kewl. It'll be even more kewl if it shames the vendors into being open with their bitstream specifications. I have no idea why they seem to feel this needs to be held so close to their chests. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com
Reply by ●July 27, 20152015-07-27
On 7/27/2015 1:57 PM, Tim Wescott wrote:> On Mon, 27 Jul 2015 12:34:21 -0400, rickman wrote: > >> I am very impressed. I was reading about Antti's incredibly tiny FPGA >> project board and saw a mention of a FOSS FPGA toolchain. Not just the >> compiler, but the entire bitstream generation! >> >> http://hackaday.com/2015/07/03/hackaday-prize-entry-they-make-fpgas- > that-small/ >> >> Several people have built on each other's work to provide "a fully open >> source Verilog to bitstream development tool chain for the Lattice >> iCE40LP with support for more devices in the works." >> >> http://hackaday.com/2015/05/29/an-open-source-toolchain-for-ice40-fpgas/ >> >> https://github.com/cseed/arachne-pnr >> >> I haven't tried any of it yet, but I am very impressed that they are >> reverse engineering the devices so that they can generate bit streams >> and not rely on the vendor. > > Kewl. > > It'll be even more kewl if it shames the vendors into being open with > their bitstream specifications. I have no idea why they seem to feel > this needs to be held so close to their chests.I seriously doubt this will ever happen. They have all done this nearly 100% of the time and I'm sure they are convinced it is the best way to do business. From what they have said their concern is that with open source tools their hardware will be subject to "problems" caused by poor tools. Or maybe they limit access to chip features through the tools which they couldn't do with FOSS tools. I seem to recall someone ranting that a line of Altera parts had some devices which were labeled as smaller chips but would load and run a bitstream for a larger part. I expect this would show up quickly and clearly if the tools were FOSS. Those who have been in this business long enough may remember the line of parts Xilinx made specifically to support an open bit stream. It was popular with academia and a number of papers were written about researchy things you might do with it. I'm not sure what Xilinx's motive was for producing these chips, but they dropped the line and crushed the molds. I'm pretty sure there is no mention of these parts anywhere on their site now. Or did I only dream all of that? -- Rick
Reply by ●July 27, 20152015-07-27
> Those who have been in this business long enough may remember the line of > parts Xilinx made specifically to support an open bit stream. It was > popular with academia and a number of papers were written about researchy > things you might do with it. I'm not sure what Xilinx's motive was for > producing these chips, but they dropped the line and crushed the molds. > I'm pretty sure there is no mention of these parts anywhere on their site > now. Or did I only dream all of that?Maybe you will also be interested in this: https://recon.cx/2015/slides/recon2015-18-andrew-zonenberg-From-Silicon-to-Compiler.pdf Tomas D.
Reply by ●July 28, 20152015-07-28
On Mon, 27 Jul 2015 14:30:34 -0400, rickman wrote:> On 7/27/2015 1:57 PM, Tim Wescott wrote: >> On Mon, 27 Jul 2015 12:34:21 -0400, rickman wrote: >> >>> I am very impressed. I was reading about Antti's incredibly tiny FPGA >>> project board and saw a mention of a FOSS FPGA toolchain. Not just >>> the compiler, but the entire bitstream generation!>>> http://hackaday.com/2015/05/29/an-open-source-toolchain-for-ice40-fpgas/>Excellent! Though I'm not surprised it's Lattice, I vaguely recall looking through an early (pre-2000) toolchain of theirs and thinking the details were closer to the surface than with other vendors.> Those who have been in this business long enough may remember the line > of parts Xilinx made specifically to support an open bit stream. It was > popular with academia and a number of papers were written about > researchy things you might do with it. I'm not sure what Xilinx's > motive was for producing these chips, but they dropped the line and > crushed the molds. I'm pretty sure there is no mention of these parts > anywhere on their site now. Or did I only dream all of that?Indeed you didn't dream the XC6200 series. It wasn't so much that Xilinx developed them, as they bought the company that did (Algotronics or Algotronix I think, based in Edinburgh). Presumably they bought them for tech in general or possibly some key patents rather than the specific device family. Which was something of a dead end in other respects, too fine grained (I believe' 1 gate, 1FF per CLB). Much simpler and more regular, but wouldn't scale too well to million-CLB devices dominated by routing, where the XC4000 and later devices would give the same capacity with a much smaller and cheaper die. I think it was that simple regular structure that made opening the bitstream format attractive, as well as killing the device long-term. You may also recall a company that successfully reverse-engineered the bitstream for Xilinx devices, and started to market their own independent toolchain. Yup, Xilinx bought them too. But their name lives on in the .ncd (neocad) file extension. -- Brian
Reply by ●July 28, 20152015-07-28
On 7/28/2015 6:06 AM, Brian Drummond wrote:> On Mon, 27 Jul 2015 14:30:34 -0400, rickman wrote: > >> On 7/27/2015 1:57 PM, Tim Wescott wrote: >>> On Mon, 27 Jul 2015 12:34:21 -0400, rickman wrote: >>> >>>> I am very impressed. I was reading about Antti's incredibly tiny FPGA >>>> project board and saw a mention of a FOSS FPGA toolchain. Not just >>>> the compiler, but the entire bitstream generation! > >>>> http://hackaday.com/2015/05/29/an-open-source-toolchain-for-ice40- > fpgas/ >> > > Excellent! Though I'm not surprised it's Lattice, I vaguely recall > looking through an early (pre-2000) toolchain of theirs and thinking the > details were closer to the surface than with other vendors. > >> Those who have been in this business long enough may remember the line >> of parts Xilinx made specifically to support an open bit stream. It was >> popular with academia and a number of papers were written about >> researchy things you might do with it. I'm not sure what Xilinx's >> motive was for producing these chips, but they dropped the line and >> crushed the molds. I'm pretty sure there is no mention of these parts >> anywhere on their site now. Or did I only dream all of that? > > Indeed you didn't dream the XC6200 series. It wasn't so much that Xilinx > developed them, as they bought the company that did (Algotronics or > Algotronix I think, based in Edinburgh). Presumably they bought them for > tech in general or possibly some key patents rather than the specific > device family. > > Which was something of a dead end in other respects, too fine grained (I > believe' 1 gate, 1FF per CLB). Much simpler and more regular, but > wouldn't scale too well to million-CLB devices dominated by routing, > where the XC4000 and later devices would give the same capacity with a > much smaller and cheaper die. > > I think it was that simple regular structure that made opening the > bitstream format attractive, as well as killing the device long-term. > > You may also recall a company that successfully reverse-engineered the > bitstream for Xilinx devices, and started to market their own independent > toolchain.It has been a very long time, but I don't think NeoCAD was spitting out bitstreams for Xilinx parts where they? I may not remember it right, but I thought their claim to fame was their router which did a better job than the Xilinx tools which is why Xilinx bought them. Rather than bury the NeoCAD tools and moving on, they shipped the NeoCAD tools as their main tool. They reverse engineered the routing I know. I guess it wouldn't be so hard to figure out the bit stream too. I recall that NeoCAD was supporting other companies because they realized what a large job it was to write their own tools. So other new entries to the market used NeoCAD as their only tool. There were clauses in place to give them rights to the software if NeoCAD was bought by a competitor, which is what happened. I'm not sure that was much solace since they all ended up having to support their own software at that point which is what they were trying to get away from.> Yup, Xilinx bought them too. But their name lives on in the .ncd (neocad) > file extension.I seem to recall having the NeoCAD tools for some product other than Xilinx. It may be the ORCA devices which Lucent produced with their license from Xilinx. Not an XC4000 clone, but used Xilinx patents with similar functionality. I seem to recall they had the first CLBs where all components were not equivalent. Lattice does that in several of their FPGA lines now that they have the Lucent FPGA products and Xilinx licenses. I recall that Altera has terms in their software to limit what you can do with the bit stream. If you want to make an ASIC you *have* to come to them. That killed a company who was providing exactly that service, bit stream to ASIC. Do all the FPGA makers do that? I would think that alone would be reason enough to reverse engineer the bit stream. That company could then produce the bit stream themselves which would retain the 1:1 relation between your verified FPGA design and the ASIC. Maybe that is why FPGA companies don't want FOSS tools? It would take away their ASIC business. Is that very popular anymore? I haven't seen it promoted in years. -- Rick
Reply by ●July 28, 20152015-07-28
On Tue, 28 Jul 2015 13:32:39 -0400 rickman <gnuarm@gmail.com> wrote:> I recall that NeoCAD was supporting other companies because > they realized what a large job it was to write their own > tools. So other new entries to the market used NeoCAD as > their only tool. There were clauses in place to give them > rights to the software if NeoCAD was bought by a competitor, > which is what happened. I'm not sure that was much solace > since they all ended up having to support their own software > at that point which is what they were trying to get away from. > > > Yup, Xilinx bought them too. But their name lives on in > > the .ncd (neocad) file extension. > > I seem to recall having the NeoCAD tools for some product > other than Xilinx. It may be the ORCA devices which Lucent > produced with their license from Xilinx. Not an XC4000 clone, > but used Xilinx patents with similar functionality. I seem to > recall they had the first CLBs where all components were not > equivalent. Lattice does that in several of their FPGA lines > now that they have the Lucent FPGA products and Xilinx > licenses.And NeoCAD is still around: ************************************************************ ** Lattice Synthesis Engine ** ************************************************************ synthesis -f "spi12_impl1_lattice.synproj" synthesis: version Diamond (64-bit) 3.4.0.80 Copyright (c) 1991-1994 by NeoCAD Inc. All rights reserved. Copyright (c) 1995 AT&T Corp. All rights reserved. Copyright (c) 1995-2001 Lucent Technologies Inc. All rights reserved. Copyright (c) 2001 Agere Systems All rights reserved. Copyright (c) 2002-2014 Lattice Semiconductor Corporation, All rights reserved. Tue Jul 28 19:53:33 2015 Jan Coombs -- email valid, else fix dots and hyphen jan4clf2014@murrayhyphenmicroftdotcodotuk
Reply by ●July 28, 20152015-07-28
On Tue, 28 Jul 2015 10:06:48 +0000 (UTC) Brian Drummond <brian@shapes.demon.co.uk> wrote:> On Mon, 27 Jul 2015 14:30:34 -0400, rickman wrote: > > > Those who have been in this business long enough may > > remember the line of parts Xilinx made specifically to > > support an open bit stream. [...] I'm pretty sure there > > is no mention of these parts anywhere on their site now. Or > > did I only dream all of that? > > Indeed you didn't dream the XC6200 series. It wasn't so much > that Xilinx developed them, as they bought the company that > did (Algotronics or Algotronix I think, based in Edinburgh). > Presumably they bought them for tech in general or possibly > some key patents rather than the specific device family. > > Which was something of a dead end in other respects, too fine > grained (I believe' 1 gate, 1FF per CLB). Much simpler and > more regular, but wouldn't scale too well to million-CLB > devices dominated by routing, where the XC4000 and later > devices would give the same capacity with a much smaller and > cheaper die.How about half a half a LUT or FF per CLB then? The Microsemi "IGLOO nano Low Power Flash" FPGAs are very similar in size and capability to the Lattice iCE40 range, except: The basic building block is either a flop or a LUT3 equivalent circuit, and these are then grouped into 8x8 blocks. [1] Innovation seems to come from smaller companies: as Lattice inherited the iCE40 series from SiliconBlue, Microsemi got the IGLOO parts from Actel, and the technology seen even earlier with ConcurrentLogic. An open-source toolchain for the IGLOO parts could be an unusually powerful tool in the hands of a creative designer. Jan Coombs -- [1] pg 73 of http://www.microsemi.com/document-portal/doc_view/130695-igloo-nano-low-power-flash-fpgas-datasheet email valid, else fix dots and hyphen jan4clf2014@murrayhyphenmicroftdotcodotuk
Reply by ●July 28, 20152015-07-28
On 7/28/2015 3:55 PM, Jan Coombs <Jan-54 wrote:> On Tue, 28 Jul 2015 10:06:48 +0000 (UTC) > Brian Drummond <brian@shapes.demon.co.uk> wrote: > >> On Mon, 27 Jul 2015 14:30:34 -0400, rickman wrote: >> >>> Those who have been in this business long enough may >>> remember the line of parts Xilinx made specifically to >>> support an open bit stream. [...] I'm pretty sure there >>> is no mention of these parts anywhere on their site now. Or >>> did I only dream all of that? >> >> Indeed you didn't dream the XC6200 series. It wasn't so much >> that Xilinx developed them, as they bought the company that >> did (Algotronics or Algotronix I think, based in Edinburgh). >> Presumably they bought them for tech in general or possibly >> some key patents rather than the specific device family. >> >> Which was something of a dead end in other respects, too fine >> grained (I believe' 1 gate, 1FF per CLB). Much simpler and >> more regular, but wouldn't scale too well to million-CLB >> devices dominated by routing, where the XC4000 and later >> devices would give the same capacity with a much smaller and >> cheaper die. > > How about half a half a LUT or FF per CLB then? > > The Microsemi "IGLOO nano Low Power Flash" FPGAs are very > similar in size and capability to the Lattice iCE40 range, > except: > > The basic building block is either a flop or a LUT3 equivalent > circuit, and these are then grouped into 8x8 blocks. [1] > > Innovation seems to come from smaller companies: as Lattice > inherited the iCE40 series from SiliconBlue,I wouldn't say Lattice "inherited" the iCE40 family. That was what they bought, the rest of the SiBlue company came for free.> Microsemi > got the IGLOO parts from Actel, and the technology seen > even earlier with ConcurrentLogic.I don't think Concurrent Logic ended up in the hands of Actel. I know they were bought by Atmel and died a very slow death of being unfunded. I received training from the guy at Atmel who was the champion of that line. They never made an effort to keep up with process technology advances to reduce the costs. That said, I expect they knew the way to go was something more like the Xilinx/Altera routes. The fine grained architecture without routing resources just won't work for larger designs. As Xilinx used to say, "We sell you the routing and give you the logic for free."> An open-source toolchain for the IGLOO parts could be an > unusually powerful tool in the hands of a creative designer.I have looked at the Igloo parts but never been impressed. Why would an open source tool chain improve them or any other part? -- Rick
