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I'm looking for an open source verilog synthesizer. I am using Icarus Verilog as a verilog simulator. Originally I was going to use it for both simulation and synthesis, but found out the tool no longer supports synthesis. I have found the gEDA website and I have looked around there, but was not able to find a replacement synthesizer.

I am doing this because I have a Papilio FPGA dev board and want to start to use verilog with it.

Also, if you could shed some light on the process from going from Verilog to FPGA that would be great. I feel as though there are more steps in the process from going from Verilog to FPGA than just simulation and then synthesis.

slashoofpez
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  • A major underlying problem is the lack of open source standard cell libraries: https://www.quora.com/Are-there-good-open-source-standard-cell-libraries-to-learn-IC-synthesis-with-EDA-tools and FPGA documentation, which. – Ciro Santilli OurBigBook.com Sep 25 '17 at 06:57

3 Answers3

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Synthesis is highly dependent on the platform you're using and usually needs to be done by tools created by Altera, Xilinx, etc. Nothing open source exists (AFAIK) because this is so custom and requires a lot of effort to obtain optimal and correct results. Therefore, there's little incentive to do open source. Also, because of the IP, these companies don't share information about their chip internals, which prevents others from using them without going through the manufacturers.

By the way, Altera and Xilinx (perhaps others) provide free versions of their tools with some features missing you can use (which is another reason no one seems to do anything open source). They're good enough for many projects.

So, to summarize, do you think anyone would spend time, for no money, to create something that is difficult, with little information, when the manufacturer already provides some of it for free? Take a look at the open source BIOS for PCs. Hasn't gone very far for these same reasons.

Gustavo Litovsky
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  • Ahh ok that makes why they discontinued support in icarus verilog then. So in this case it would be best to go with the vendor's tools? I was hesitant to do this because I downloaded Xilinx's ISE webpack and it was huge. I was just looking for something a little more lightweight. Thanks for the response. – slashoofpez Mar 11 '13 at 17:17
  • @slashoofpez: Yes. They are huge (which tells you how much it takes to support it), but you can cut down on the number of FPGAs you want to support so the installation is smaller (perhaps even download if it's an online installation). – Gustavo Litovsky Mar 11 '13 at 17:18
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There are some open research synthesizers that are getting close - VTR (Verilog to Routing) and Yosys Open SYnthesis Suite deliver the most promising tools.

If your aim is to deliver a chip rather than research routing algorithms then (at least in 2013) you need vendor tools.

shuckc
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    And in 2017, the Yosys pipeline produces working design for some small Lattice parts! – shuckc Sep 25 '17 at 15:29
  • And in 2022 Yosys plus a host of chip-specific tools can generate designs for a variety of fpga parts, plus metal designs for open source integrated circuits. – shuckc Mar 28 '22 at 13:23
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There are no open source synthesizers. People (and especially enthusiast) stick with vendor tools. Given that Papillo comes with Xilinx Spartan 3E FPGA, you can use Xilinx's ISE WebPACK, which is free.

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    There are none for FPGAs, but there actually are a few for developing full-custom silicon (ASICs). See, for example http://opencircuitdesign.com/verilog/ – Dave Tweed Mar 11 '13 at 18:53