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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
I am trying to determine which of these two to buy for my work. I have used SIMULINK but not LabVIEW. Is there anyone who has used both and would like to provide some details? My investigation criteria are the user friendliness, availability of libraries and template functions, real-time probing facility, COTS hardware interfacing opportunity, quality of code generation, design for testability (i.e. ease of generating unit/acceptance tests), etc. However, if anyone would like to educate me with more criteria, please do so by all means!
For anyone who does not know about SIMULINK and LabVIEW - These are both Domain-Specific Languages (DSLs) intended for graphical dataflow modelling (and also code generation). These are multi-industrial tools and quite heavily used for engineering design and modelling.
IMPORTANT - I am quite interested to know if SIMULINK and LabVIEW offer real-time probing. For example, I have a model that I want to simulate. If there are variables associated to certain building blocks in that model, could I view them changing as the simulation continues? I know that it is certainly not possible with SIMULINK as it has a step-by-step debugger. I am not aware of anything similar in LabVIEW.
I really have not used LabVIEW and cannot obtain it temporarily as my work internet has got download restrictions and administrative privilege issues. This is the reason why I simply cannot use only NI website to draw conclusions. If there is any white paper available that addresses this issue, I would also love to know :)
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I have used MATLAB code generator and will not say that it is the best. However, I hear now that SIMULINK Embedded Coder is the best code generator and almost one of its own kind. Can anyone confirm whether or not this is good for safety critical system design i.e. generating code from safety-critical subsystem models. I know that the Mathworks is constantly trying to close the gap to achieve fully-flexible production-level C/C++ code generation.
I know that an ideal answer would be,"Depending on what you are trying to do, use a bit of both". And interestingly, I think I am heading to that direction. ATEOTD, it is a lot of money and need to be spent "nicely".
Thanks in advance.
I used labVIEW from 1995, and Simulink from 2000. Now I am involved in control system design, and simulation of robotic systems using labVIEW Real Time and automotive ECUs using MATALAB/Simulink/DSPACE .
LabVIEW is focus on measurement systems, and MATLAB/SIMULINK in dynamic simulation, so,
If you run complex simulations, and your work is create/debug complex simulation models of controllers or plants, use Simulink+RealTimeWorkShop+StateFlowChart. LabVIEW has no eficient code generators for dynamic simulation. RTW generates smaller and fastest code.
If your main work is developing systems with controllers and GUI for machines, or you want to deploy the controllers on field, use labVIEW.
If your main work is developing flexible HIL or SIL systems, with a good GUI, you can use VeriStand. Veristand can mix Simulink and LabVIEW code.
And if you have a big budget ( VERY BIG ) and you are working in automotive control prototypes, DSPACE hardware is a very good choice for fast development of automotive ECUS, or OPAL to develope electric power circuits. But only for prototype or HIL testing of controllers.
From the point of view of COTS hardware:
Mathworks don´t manufacture hardware -> Matlab/Simulink support hardware from several vendors.
National Instruments produce/sell hardware->LabVIEW Real Time is focused in support NationalInstruments hardware. There are no COTS full replacement.
I have absolutely no experience with Simulink, so I'll comment only on LV, although a quick read about Simulink on Wikipedia seems to indicate that it's focused mainly on simulation and modelling, which is certainly not the case with LabVIEW.
OK, so first of all, LV is NOT a DSL. While you wouldn't want to use it for any project, it's a general purpose programming language and you should take that into account. I know that NI has a simulation toolkit for LV, which might help you if that's what you're after, but I have absolutely no experience with it. The images I saw of it seemed to indicate that it adds a special kind of diagram to LV for simulation.
Second, LV is not restricted to any kind of hardware. It's a general purpose language, so you can write code which won't use any hardware at all, code which will use or run on NI's hardware or code which will use any hardware (be it through DLL calls, .NET assemblies, RS232, TCP, GPIB or any other option you can think of). There is quite a large collection of LV drivers for various devices and the quality of the driver usually depends on who wrote it.
Third, you can certainly probe in real time in LV. You write your code, just as you would in C or Java, and when you run it, you have several debugging options:
Single stepping. This isn't actually all that common, partially because LV is parallel.
Execution highlighting. This runs the code in slow motion, while showing all the values in the various wires.
Probes, which show you the last value that each wire had, where wires fill the same function that variables do in text based languages. This updates in real time and I assume is what you want.
Retain wire values, which allows you to probe a wire even after data passed through it. This is similar to what you get in text based IDEs with variables. In LV you don't usually have it because wire values are transient, so the value is not kept around unless you explicitly ask for it.
Of course, since you're talking about code, you could also simply write the code to display the values to the screen on a graph or a numeric indicator or to log them to a file, so there should be no need for actual probing. You could also add analysis code, etc.
Fourth, you could try downloading and running LV in a fully functional evaluation mode. If I remember correctly, NI currently gives you 7 days and then 45 days if you register on their site. If you can't do that on a work computer, you could try at home. If your problem is only with downloading, you could try contacting your local NI office and asking them to send you a DVD.
Note that I don't really know anything about modelling and simulation, so I have no idea what kind of code you would actually have to write in order to do what you want. I assume that if NI has a special module for it, then it's not something that you can completely cover in regular code (at least not if you want the original notation), but I would say that if you could write the code that does what you want in C, there's no reason you shouldn't be able to write it in LV (assuming, of course, that you know how to write code in LV).
A lot of the best answer would have to depend on your ultimate design requirements. Are you developing a product? If so, in what stage of development are you? Or are you doing research?
I recently did a comparison just as you are doing. I know LV, but was wanting to move towards a more hardware-scalable option, since NI HW is very expensive in volume. That is, my company was wanting to move towards a product. What LV and NI HW give you is flexibility. You can change code very quickly compared to C. On the other hand, LV does not run on nearly as many different HW platforms as C. So I wanted to find an inexpensive platform that would work well for real-time control and data acquisition, such that if we wanted to sell a product for, say, $30k, our controller wouldn't be costing $15k of that. We ended up with Diamond Systems Linux SBC's. Interestingly, Simulink ended up using the most expensive hardware! It did have a lot of flexibility, and could generate code, as well as model plants and controllers. But then, LV can do that as well.
As Yair wrote, LV has plenty of good debugging tools. One of the more interesting tools that is not so well known is the Suspend when Called option for a SubVI. This allows you to play with the inputs and outputs of a SubVI as much as you want while execution is paused.
MATLAB and Simulink are the defacto standard for control system design and simulation. Simulink controller models can be used for offline simulation in conjunction with plant models, all the way to realtime implementation on embedded targets. It is a general simulation framework with extensive built-in libraries as well as a la carte special purpose libraries, and can be extended through creation of custom blocks (S-function blocks) in C and other languages. It includes the ability to display values in graphs, numeric displays, gages, etc. while a nonrealtime simulation is taking place. Realtime target support from The Mathworks includes x86 (xPC Target) and several embedded targets (MPC555, etc.), and there is 3rd party support for other targets. The aforementioned dSPACE provides complete prototyping controllers including support for their quite powerful hardware. xPC Target includes support for a plethora of COTS PC data acquisition cards. Realtime target support includes GUI elements such as graphs, numeric displays gages, etc.
As I understand it (I have never really used it in anger), LabView only supports NI hardware, and is more hardware-oriented. Simulink supports hardware from multiple vendors, be it for data acquisition, or real-time implementation, but it may require a bit more work for the user to interface to his or her own hardware (less plug & play than LabView). On the other hand, Simulink provides tools to support the whole model-based design process, from modelling & simulation, control design, verification & validation, code generation, hardware-in-the-loop, etc...
Disclaimer: I used to work for MathWorks.
You guys may really be interested in Control Design adn Simulation Module for LabVIEW. It does a lot of simulations and in the future may be competitive to Simulink. I'm not a control engineer but I use it sometimes for simple testing and I'm glad that I don't have to learn Simulink from the beginning to do some work since I'm familiar with LabVIEW philosophy.
I am unsure whether this question belongs here, so please feel free to migrate it if it doesn't.
My question is this, Is it possible to combine many different PC units to work as one?
Take for example, buying 3 different HP desktop PCs. Then link the hardware so that they act as one PC.
If so, please point me to some resources I can use.
Thanks for your time.
Note
I am not referring to linking them over a network, but rather, making the actual hardware work together.
I am not sure this is possible, so I am sure all my google search terms are not related to the issue.
You should realize that linking them over a network does not obviate their ability to work together to complete a task. Most supercomputers and clusters today are interconnected via a network (albeit a very high speed one like Infiniband). The key is to have software that can understand that it's operating in a distributed environment (e.g. MPI libraries). You might also take a look at OpenMP or Hadoop. It really depends on what you want to do with it.
You can not link some computer together to behave like one!!! Therefore you will need special hardware, which offers you the possibility to extend the numbers of CPU's working together. (Like a cray)
If you are talking about write an application that will be processed by those computers, you may be referring to MPI.
You can use the Open MPI to do that, most of languages nowdays have MPI libraries.
You can find a more elaborated information about Parallel Computing on Wikipedia Parallel Computing Article.
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I am planning to develop an operating system for the x86 architecture.
What options of programming languages do I have?
What types of compilers are there available, preferably on a Windows environment?
Are there any good sources that will help me learn more about operating system development?
Is it better to test my operating system on a Virtual Machine or on physical hardware?
Any suggestions?
For my final year project in collage I developed a small x86 OS with a virtual memory manager, a virtual file system and fully preemptive multitasking. I made it open source and the code is heavily commented, check out its source forge page at:
https://github.com/stephenfewer/NoNameOS
From my experience I can recommend the following:
You will need x86 assembly language for various parts, this in unavoidable, but can be kept to a minimum. Fairly quickly you will get running C code, which is a proven choice for OS development. Once you have some sort of memory manager available you can go into C++ if you like (you need some kind of memory manager for things like new and delete).
No matter what language you choose you will still need assembly & C to bring a system from boot where the BIOS leaves you into any useable form.
Ultimately, the primary language you choose will depend on the type of OS you want to develop.
My development environment was the Windows port of the GNU development tools DJGPP along with the NASM assembler. For my IDE I used IBM's Eclipse with the CDT plugin which provides a C/C++ development environment within Eclipse.
For testing I recommend BOCHS, an open source x86 PC emulator. It lets you boot up your OS quickly which is great for testing and can be integrated into eclipse so you can build and run your OS at the push of a button. I would also recommend using both VMWare and a physical PC occasionally as you can pick up on some subtle bugs that way.
P.S. OS development is really fun but is very intensive, mine took the best part of 12 months. My advice is to plan well and your design is key! enjoy :)
Language and compiler depend entirely on what you're attempting to accomplish. I would suggest, though, that you might be approaching the problem from too low a level.
There are materials out there on operating system fundamentals. MIT has OpenCourseware on the subject. Read through Andrew Tannenbaum's Operating Systems series, and look at things like Minix.
Get an idea for what's out there. Start tinkering with things. Borrow ideas, and see where they go. You can reinvent the wheel if you really want, but you'll learn more by building on the works of others.
It doesn't really matter, what language you choose. If the language is Turing-complete, then you can write an OS in it.
However, the expressiveness of the language will make certain kinds of designs very easy or very hard to implement. For example, the "liveliness" and dynamism of the old Smalltalk OSs depends on the fact that they are implemented in Smalltalk. You could do that in C, too, but it would probably be so hard that you wouldn't even think about it. JavaScript or Ruby OTOH would probably be a great fit.
Microsoft Research's Singularity is another example. It simply couldn't be implemented in anything other than Sing#, Spec# and C# (or similar languages), because so much of the architecture is dependent on the static type safety and static verifiability of those languages.
One thing to keep in mind: the design space for OSs implemented in C is pretty much fully explored. There's literally thousands of them. In other languages, however, you might actually discover something that nobody has discovered before! There's only about a dozen or so OSs written in Java, about half a dozen in C#, something on the order of two OSs in Haskell, only one in Python and none in Ruby or JavaScript.
Try writing an OS in Erlang or Io, and see how that influences your thinking about Operating Systems!
There is an OS course offered at the University of Maryland that utilizes GeekOS. This is a small, extensively commented OS designed for educational purposes which can be run using the Bochs or QEMU emulators.
For an example of how it is used in a course, check out a previous offering of the course at the class webpage. There, you will find assignments where you have to add different functionality to GeekOS.
Its a great way to get familiar with a small and simple OS that runs on the x86 architecture.
You might want to look up XINU. it's a tiny OS for x86 that isn't really used for anything other than to be dissected by students.
Use ANSI C, and start off with an emulator.
When you port over to a real machine, there will be some assembler code. Context switching and interrupt handling (for instance) is easier to write in assembler.
Andy Tannenbaum has written a good book on OS. Many other good ones exist.
Good luck! There is nothing quite like haveing written your own OS, however small.
Also check out the OSDev.org which have all information you need to get started.
I've done that once for a 386SX, which was on a PCI board. A good source on how to start a X86 cpu in protected mode is the source code of linux. It's just a few assembly statements. After that you can use gcc to compile your C code. The result is objectcode in ELF format. I wrote my own linker, to make a program out of the objectcode. And yes, it worked! Good luck.
Be sure to check out the answers to my question:
How to get started in operating system development
Without a doubt, I'd use Ada. It's the best general-purpose systems-programming language I have come across, bar none. One example, Ada's much better for specifying bit layout of objects in a record than C. Ada also supports overlaying records on specific memory locations. C requires you to play with pointers to acheive the same effect. That works, but is more error-prone. Ada also has language support for interrupts.
Another: Safety. Ada defaults to bound checking array assignments, but allows you to turn it off when you need it. C "defaults" to no bound checking on arrays,so you have to do it yourself manually whenever you want it. Time has shown that this is not the right default. You will forget one where it is needed. Buffer overflow exploits are the single most common security flaw used by crackers. They have whole websites explainng how to find and use them.
As for learning about doing this, the two books I'm aware of are XINU (Unix backwards, nothing to do with Scientology), and Project Oberon. The first was used in my Operating Systems graduate course, and the second was written by Nikalus Wirth, creator of Pascal.
If you are making a full OS, you will need to use a range of languages. I would expect Assembly, C and C++ at the very least.
I would use a Virtual Machine for most of the testing.
C most probably...all major OS-es have been written in C/C++ or Objective-C(Apple)
If you want write an OS then you need a couple of people. A OS can not write a single people. I think it is better to work on existing OS projects
Reactos --> C, Assembler
SharpOS --> C#
JNode --> Java
This is only a short list of OS projects. How you can see there is a project for every possible language.
I would like to make a list of remarkable robot simulation environments including advantages and disadvantages of them. Some examples I know of are Webots and Player/Stage.
ROS will visualize your robot and any data you've recorded from it.
Packages to check out would rviz and nav_view
This made me remember the breve project.
breve is a free, open-source software package which makes it easy to build 3D simulations of multi-agent systems and artificial life.
There is also a wikipage listing Robotics simulators
Microsoft Robotics Studio/Microsoft Robotics Developer Studio 2008
Also read this article on MSDN Magazine
It all depends on what you want to do with the simulation.
I do legged robot simulation, I am coming from a perspective that is different than mobile robotics, but...
If you are interested in dynamics, then the one of the oldest but most difficult to use is sd/fast. The company that originally made it was acquired by a large cad outfit.
You might try heading to : http://www.sdfast.com/
It will cost you a bit of money, but I trust the accuracy of the simulation. There is no contact or collision model, so you have to roll you own. I have used it to simulate bipeds, swimming fish, etc.. There is also no visualization. So, it is for the hardcore programmer. However, it is well respected among us old folk.
OpenDynamics engine is used by people http://www.ode.org/ for "easier" simulation. It comes with an integrator and a primitive visualization package. There are python binding (Hurray for python!).
The build in friction model.. is ... well not very well documented. And did not make sense. Also, the simulations can suddenly "fly apart" for no apparent reason. The simulations may or may not be accurate.
Now, MapleSoft (in beautiful Waterloo Canada) has come out with maplesim. It will set you back a bit of money but here is what I like about it:
It goes beyond just robotics. You can virtually anything. I am sure you can simulate the suspension system on a car, gears, engines... I think it even interfaces with electrical circuit simulation. So, if you are building a high performance product, than MapleSim is a strong contender. Goto www.maplesoft.com and search for it.
They are pretty nice about giving you an eval copy for 30 days.
Of course, you can go home brew. You can solve the Lagrange-Euler equations of motion for most simple robots using a symbolic computation program like maple or mathematica.
EDIT: Have not be able to elegantly do certain derivatives in Maple. I have to resort to a hack.
However, be aware of speed issue.
Finally for more biologically motivated work, you might want to look at opensim (not to be confused with OpenSimulator).
EDIT: OpenSim shares a team member with SD/Fast.
There a lots of other specialized simulators. But, beware.
In sum here are the evaluation criteria for a simulator for robot oriented work:
(1) What kind of collision model do you have ? If it is a very stiff elastic collision, you may have problem in numerical stability during collisions
(2) Visualization- Can you add different terrains, etc..
(3) Handy graphical building tools so you don't have to code then see-what-you-get.
Handling complex system (say a full scale humanoid) is hard to think about in your head.
(4) What is the complexity of the underlying simulation algorithm. If it is O(N) then that is great. But it could be O(N^4) as would be the case for a straight Lagrange-Euler derivation... then your system just will not scale no matter how fast your machine.
(5) How accurate is it and do you care?
(6) Does it help you integrate sensors. For mobile robots you need to have a "robot-eyes view"
(7) If it does visualization, can it you do things like automatically follow the object as it is moving or do you have to chase it around?
Hope that helps!
It's not as impressive looking as Webots, but RobotBasic is free, easy to learn, and useful for prototyping simple robot movement algorithms. You can also program a BasicStamp from the IDE.
I've been programming against SimSpark. It's the open-source simulation engine behind the RoboCup 3D Simulated Soccer League.
It's extensible for different simulations. You can plug in your own sensors, actuators and models using C++, Ruby and/or RSG (Ruby Scene Graph) files.
ABB has a quite a solution called RobotStudio for simulating their huge industrial robots. I don't think it's free and I don't guess you'll get much fun out of it but it's quite impressive. Here's a page about it
I have been working with Carmen http://carmen.sourceforge.net/ and find it useful.
One of the disadvantages with Carmen is the documentation with all respect I think the webpage is a bit outdated and insufficient. So I like to hear from other people with experience in working with Carmen, or student reports/projects dealing with Carmen.
You can find a great list with simulation environments http://www.intorobotics.com/robotics-simulation-softwares-with-3d-modeling-and-programming-support/
MRDS is one of the best and it's free. Also LabView is good to be used in robotcs
National Instruments' LabView is a graphical programming environment for developing measurement, test, and control systems.
It could be used for 3D control simulation with SolidWorks.
MRDS is free and is one of the best simulation environment for robotics. Workspace also can be used, and please check this link if you want a complete list with robotics simulation software
Trik Studio has a nice and clear 2D model simulator and also visual and textual programming programming environments for them. They also soon will support 3D modeling tools based on Morse simulator. Also it is free and opensource and has multi-language interface.