How to connect SystemC model with SystemVerilog? - system-verilog

Say we have a SystemC model of decade counter and I want to verify SystemVerilog Counter RTL using SystemC model. How can we connect these two in SV/UVM based testbench so as to communicate between them.

Mentor developed a free package called UVMConnect that was developed specifically for the application you are asking about. See https://verificationacademy.com/topics/verification-methodology/uvm-connect. You will need a simulator that supports SystemVerilog and SystemC simulating together, like Questa.

If you're using QuestaSim I think UVM-connect from Mentor is the way to go. When I first used it(4 years ago) it was very buggy and gave the most cryptic segfault errors I've ever seen. But, with help from the Mentor support I managed to overcome them and get stuff done. It should be more stable now, but if you have problems with it don't hesitate to contact Mentor support. They are very responsive.
However, if you're using Cadence tools and/or the e language I think that UVM-ML from Cadence is a much more comprehensive solution. It allows you to connect components written in any combination of languages(SV-SC, SV-e, SC-e) and it has nicer documentation and examples. I understand it's also compatible with all simulators now. You can find it here : http://forums.accellera.org/files/file/65-uvm-ml-open-architecture/
Not sure what Synopsis folks recommend for their tool suite. Maybe someone who used them can offer more information on this. But I'm guessing that both UVM-ML and UVM-Connect could work since their makers claim that they are portable.
And lastly, if you're planning to use SystemC as a verification language(very unlikely but just for the sake of diversity) there is something called UVM-SystemC which is basically a clone of SV-UVM written in C++/SystemC. It's currently in its alpha release and it lacks many features(register modeling, constrained randomization, coverage collection, etc.). It feels a lot like SV-UVM and I think it's a nice toy to play with in your spare time if you can't afford a commercial simulator license. You can find it here http://accellera.org/images/downloads/drafts-review/uvm-systemc-1.0-alpha1.tar.gz

Related

Developing an Operating System using TDD/BDD

I just wonder. Is there anybody in the world, using TDD or BDD to write an OS? And is this even posible? I've tried to google it, but didn't find any kind of information.
So, guys. Is it possible to build an entire OS using TDD? And BDD?
It is possible to use TDD for most of OS development and for most of the code. It may get tricky at certain times/places due to limited testability of low-level, especially CPU/hardware-specific, code. These parts either may receive less direct test coverage (if that's OK) or can be tested in virtual machines or CPU/PC simulators.
It is definitely possible. I don't know anyone who is doing it.
As a proof point, I would point out what people are doing with test driven infrastructure with Chef and unit and behavioral testing there. For more info, see TestKitchen for Chef.

Bringing Scala into my company

Now i know that this one is actually not a very technical question but one that has been bothering me for some time. Actually we are using a lot of C++ and PHP at our company and some of our developers are really hoping for a new and modern language to come by to help us getting more productive. I have been talking about what scala can do and the other coders seem to gain some interest in the language. The tough job is, how do you convince your boss to consider scala as a language for the company. I saw the presentation "Sneaking Scala into your company", but it deals with the situation that you are using Java at your company which we don't.
How do you fight of the usual "that is just esoteric stuff" and "we can already do that in $LANGUAGE" arguments. I was planing to give a talk about Scala, and since I don't have much time I need ideas how to get people interested in the language rather then setting of reactions like "currying? we can already do something like this with boost::bind".
How did you guys do it?
Regards,
raichoo
EDIT: Gave my talk yesterday, people were very excited. My company is going to give it a try! Thanks for all your suggestions.
If you don't already have killer arguments, what are you basing your reasoning on that Scala will make your company more productive?
Don't like something then hunt for reasons to use it at work. Let the reasons speak for themselves..
"A hammer looking for nails"
Using it to do some stuff around the side, as datamigrations, testing and similar things will make sure the necessary experience is built and can give it some exposure.
ScalaTest is really nice to help with acceptance/integration testing. (Yes, I know it is nice for unit testing, but I do not see that immediately happening with C++/PHP target code, and it would probably be unwise).
Proof of Concept and other Prototypes are great for 2 reasons
1) It showcases the capabilities
2) You are certain they will be thrown away if you have to reimplement them in C++/PHP
Now a bad time to introduce Scala would be when you REALLY need it : hopes will be high, it will not immediately work as intended, hopes are dashed and everybody will blame Scala. As a result it will be burnt for a long time in the organisation.
Sooner or later some suit will think it was his idea to introduce Scala and use it on a formal project. If that project is moderately successful, then it is sold.
These kind of changes are complicated people issues, and the harder you push, the harder you will face push-back. On the other hand the persistent mind can move mountains.
Redo some of your work related code in Scala and compare KLOC, code structure and performence, if it looks and works better, show it to your peers and your managers.
In other words:
Talk is cheap. Show me the code.
-- Torvalds, Linus (2000-08-25)
In case of our company (and I assume, many companies share the same scenario), move to Scala (from Java) was initiated by tech people, who 1. wanted to work more productive writing code (living in the 21st century utilize modern approaches), 2. have less troubles building concurrent applications (Actors concept promoted by Scala is a way simpler than Java thread-based concurrency) 2.1 have a simpler way of building scalable staged event driven architectures.
In our company, transition to Scala was more or less simple, because Scala was literlly sold to business people as a library to Java :) -> from their POV, we're still using the same platform (JVM), application servers, etc., but developers are having more fun from their work, and therefore, are more inspired and work more efficiently.
Maybe you could pitch Scala by showing off the suite of tools that is used for development? For example, if you are not already using Eclipse in your company, show your execs a demo of what a modern IDE can do for your productivity.
There is a book called "Fearless Change" (Linda Rising) that describes a pattern language for "powerless leaders" (I LOVE that role title!). SE-radio had a really motivating interview with the author: http://www.se-radio.net/podcast/2009-06/episode-139-fearless-change-linda-rising. Listen up on that interview to collect a few non-technical strategies that can help you in this struggle!
I haven't used Scala yet for any real business code, but I know people who have.
One group used it to write a tool to analyze log files. So they didn't use it for mission-critical business code, but for a non-critical tool to support the project.
Another person I know is an architect and he just went and wrote some Scala code on his own for some production code without telling his manager. After the code was deployed successfully he did tell it. One of the things he mentioned is that because Scala runs on the JVM, the people who support the application don't even notice - to them, Scala is just another library that's included with the application (they were already used to the JVM). Ofcourse this approach is risky and not everybody will be in the position or be willing to do this.
You could start small - use it as your personal preferred scripting language for small things that you need yourself. Tell your fellow developers about it and make them enthusiasts too. If they also start using it then you can step it up to make some side code for your project (such as for example that log analyser tool).
This isn't a really easy task. I would concentrate on the fact that you will be able to produce code and therefore products faster and with a higher quality. That's always the two reasons, business wants to hear from you and will listen to.
Maybe you can show an example of 1-2 very small projects you did in your company with C++/PHP and compare the effort, quality etc. with a similar/the same implemenation in Scala? This would be very impressive and should also convince people who are not on the coding side.
There was a very good talk at Scala Days 2010 by David Copeland:
Sneaking Scala into your organisation
The executive summary: Testing. You can use Scala for testing without affecting release code.

Criteria for selecting a library for Enterprise usage

What are your criteria for selection a (open source) library (or framework) for enterprise usage?
Some libraries are pretty small and can be easily checked for security flaws or tested for performance. But most libraries are too big to be reviewed before you can start to use them.
When I think of me selecting a library, most if the selection process is just gut feeling. When I try to be more specific, these are the first criteria which come to my mind:
How many developers are working on the project? My feeling is that more developers will find more bugs and security issues. In addition it will be harder to introduce security issues intentionally.
How good is the support? Compared to closed source libraries, I've got the feeling that the support of open source is often much better since you have a community around the globe which will be available whenever you need them.
How wide spread is the library? Are there any books about it on the market? Which other projects are using the library?
What are your criteria? Feel free to edit this note as community wiki.
For me, it depends on whether or not it is paid for or not. In your case, you give the impression you are looking at open source libraries.
In that specific case, I'll look at test coverage. Regardless of the number of contributors, if there aren't any unit tests that I can run myself (as well as enhance and test my use cases for if they fall outside the coverage of the unit tests provided), then that's a massive issue for me.
It's not that I don't appreciate the work that is done already in providing the library, but code in projects like this should have unit tests already with good coverage in order to gain traction.
If there are no libraries that have unit tests, then I would start searching for the library on search engines, actively seeking out negative replies. People who have negative feelings about the code and can crystalize the objective basis for those feelings in terms of how the code failed them will provide more valuable feedback than the masses that say "it works great".
Now for a commercial piece of code, it's completely different. At that point, I'd start looking at the company and it's support staff as a whole, and using that as a determination (as well as tests of your own to see if the library is right for you) as to whether or not to use that company's offering.
Quite often in open source libraries you cannot get reliable support. In such situations your best bet is to fix it yourself, which involves the following requirements.
You need to have the ability to read often messy and undocumented code.
The technical ability to ask the right questions from the right people -- i.e., these people aren't being paid to fix problems and they will only answer you if you make it easy enough for them.
Then you need the ability to fix the bug and get the patch accepted -- because if the patch isn't accepted .....
With this in mind I would be inclined to get a commercial library, or dual licensed library so that I could pay to get a competent engineer (motivated by the money I pay his company) to fix my problem.

Any good library or software for queue networks simulation?

I have been trying to make work EZSIM with no luck, which is a software to build discrete event simulators in a graphical DOS environment. In this software, my simulator and many others (of the other people in the course I'm taking) don't work, but teacher's simulator (and examples of the downloaded files) does work.
So, I began to distrust of the software.
Do you know any software that resolves the same kind of problems but really works? It will be good if it is free, or I can download an evaluation copy or something like that.
If you don't know any software, do you know any library which might work? Preferably in C#, Ansi C, Java or Delphi.
This may be more than what you're looking for, but check out NS2. It's the standard for open source network simulations, and will allow you to simulate all kinds of network layer behavior.
I've also used JUNG in the past. It's very flexible, although it also doesn't offer much out of the box.
I used Möbius in my computer systems analysis class. It is free for educational use (which sounds like what you're doing). It's a Java GUI which generates C++ code.
The R package queuecomputer. queuecomputer is a computationally efficient method for simulating queues with arbitrary arrival and service times. There is a submitted paper on arXiv describing the algorithm used in the package. Examples can be found within the arXiv paper and the vignette. A web app based on the package is available at https://ace-ebert.shinyapps.io/queue_simulator_mmk/ .

When generating code, what language should you generate?

I've worked on a number of products that make use of code generation. It seems to be the only way to achieve both a high degree of user-customizability and high execution speed.
The downside is that we are requiring users to install a compiler (primarily on MS Windows).
This has been an on-going headache, because vendors like MS keep obsoleting compilers, and some users tend to have more than one compiler installed.
We're considering using GNU C, and possibly C++, but even there, there are continual version issues.
I've considered possibly generating assembly language, in an effort to get off the compiler-version-treadmill, but assembly languages are all machine-specific.
Ideally there would be some way to produce generated code that would be flexible, run fast, and not expose us to the whims of third-party providers.
Maybe I'm overlooking something simple, like Java. Any ideas would be appreciated. Thanks.
If you're considering C and even assembler, take a look at LLVM first: http://llvm.org
I might be missing some context here, but could you just pin yourself to a specific version? E.g., .NET 2.0 can be installed side by side with .NET 1.1 and .NET 3.5, as well as other versions that will come out in the future. So as long as your code makes use of a specific version of a compiler, what's the problem?
I've considered possibly generating assembly language, in an effort to get off the compiler-version-treadmill, but assembly languages are all machine-specific.
That would be called a compiler :)
Why don't you stick to C90?
I haven't heard much of severe violations of standards from gcc's side, if you don't use extensions.
And you can always distribute a certain version of gcc along with your product, say, 4.3.2, giving an option to users to use their own compiler at their own risk.
As long as all code is generated by you (i. e. you don't embed your instructions into other's code), there shouldn't be any problems in testing against this version and using it to compile your libraries.
If you want to generate assembly language code, you may take a look at asmjit.
One option would be to use a language/environment that provides access to the compiler in code; For example, here is a C# example.
Why not ship a GNU C compiler with your code generator? That way you have no version issues, and the client can constantly generate code that is usable.
It sounds like you're looking for LLVM.
Start here: The Code Generation conference
In the spirit of "might not be to late to add my 2 cents" as in #Alvin's answer's case, here is something I'd think about: if your application is meant to last for some years, it is going to face several changes in how applications and systems work.
For instance, let's say you were thinking about this 10 years ago. I was watching Dexter back then, but I guess you actually have memories of how things were at that time. From what I can tell, multithreading was not much of an issue to developers of 2000, and now it is. So Moore's law broke for them. Before that people didn't even care about what will happen in "Y2K".
Speaking of Moore's law, processors are indeed getting quite fast, so maybe certain optimizations won't be even that necessary. And possibly the array of optimizations will be much bigger, some processors are getting optimizations for several server-centric stuff (XML, cryptography, compression and regex! I am surprised such things can get done on a chip) and also spend less energy (which is probably very important for warfare hardware...).
My point being that focusing on what exist today as a platform for tomorrow is not a good idea. Make it work today, and surely it will work tomorrow (backward-compatibility is especially valued by Microsoft, Apple is not bad it seems and Linux is very liberal about making it work as you want).
There is, yes, one thing that you can do. Attach your technology to something that just won't (likely) die, such as Javascript. I'm serious, Javascript VMs are getting terribly efficient nowdays and are just going to get better, plus everyone loves it so it's not going to dissappear suddenly. If needing more efficiency/features, maybe target the CRL or JVM?
Also I believe multithreading will become more and more of an issue. I have a gut feeling the number of processor cores will have a Moore's law of their own. And architectures are more than likely to change, from the looks of the cloud buzz.
PS: In any case, I belive C optimizations of the past are still quite valid under modern compilers!
I would stick to that language that you use for generating that language. You can generate and compile Java code in Java, Python code in Python, C# in C#, and even Lisp in Lisp, etc.
But it is not clear whether such languages are sufficiently fast for you. For top speed I would choose to generate C++ and use GCC for compilation.
Why not use something like SpiderMonkey or Rhino (JavaScript support in Java or C++). You can export your objects to JavaScript namespaces, and your users don't have to compile anything.
Embed an interpreter for a language like Lua/Scheme into your program, and generate code in that language.