Can we have an open source simulator?

In my previous post, I talked about GHDL, and why it is not good enough as an open source parser and simulator. In this post, I talk about possible solutions. I see three options today.

GHDL could become really good and perhaps even great. But in order to achieve this, the GHDL community would need to grow. Perhaps a few students would have to spend a Summer of Code working on GHDL.

Or, we could drop the idea of GHDL and start from scratch. This would be wise if the effort saved by using newer, better tools and languages, will compensate for having to start from scratch.

As a last alternative, one of the existing players could release its own simulator as open source software. This may not be as crazy as is sounds. Xilinx has dropped Mentor Graphic's ModelSim in favor of its own ISim. We can only presume that Mentor's royalties were an important factor in this decision. ISim translates VHDL and Verilog to C, which is then compiled to an executable. This executable in fact simulates the hardware design. Xilinx has much to gain from a larger community of designers: they can sell more FPGAs. They also have much to gain from a diverse EDA landscape, as they would be able to cut back on their own EDA development budgets.

We need an open source, high quality VHDL simulator. It will enable more people and companies to join the community of VHDL and FPGA designers. It will enable new players to enter the EDA market and build innovative tools. If there are more EDA vendors, they can provide more high quality EDA tools at a lower cost and less vendor lock-in.

I don't expect a lot of cheers from the companies that sell their own simulators. But if the EDA sector as a whole wants to remain healthy, it needs to allow new innovators in the market. Having a freely available parser and simulator for the cornerstone hardware description languages would be a good start.

Let me know what you think, in the comments or on Twitter.

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Philippe

Comments

Will Sigasi be starting the

Will Sigasi be starting the ball rolling by opening their VHDL parser to us all :)

Out of interest, is your parser written in Java?

Martin

Hi Martin, While our company

Hi Martin,

While our company works on a VHDL IDE as its commercial product, the first innovation we need in open-source EDA is a simulator.

Our parser is based on ANTLR v3 and Java. It is tailored for one specific purpose: to provide support for an IDE, not as a first phase for a simulator.
Because our parser/analyzer has to be interactive, it is very different from what we need for a simulator. An interactive tool needs to be fast and needs to be very tolerant for incorrect and unfinished code. On the other hand, a simulator needs a different depth in its analysis, which will take more processing power, and it can bail out on the first error.

Your question is more than justified: can Sigasi get the ball rolling? We do hope so, and we continuously evaluate how we can do that. However, at this time, as an open source project, our parser would provide little or no added value to the GHDL parser.

Philippe

I've started to write an open

I've started to write an open source VHDL 2002 compiler/simulator. It is about 30 - 40 % complete.
Source code is here: http://github.com/chrreisinger/OpenVC