CVCBLR's VoW blog - Verification on the Web!

At DVCon-14, leading EDA vendor MENT has taken the initiative to propose a Test Specification Standard (see: http://www.goo.gl/BKuNEd ). Given that SV & UVM are well established and deep into their development, stability and adoption phase, the innovation has to come at next level of abstraction. Over the last decade, we at CVC have been working with customers (semiconductor design houses) and EDA partners in defining, evangelizing and deploying multitude of technologies and languages such as OVL, e/Specman, eRM, PSL, SVA, SV, VMM, OVM, AVM, UVM etc. While most of them address the key aspects of "how verification shall be effectively carried out", the next level of "What defines my verification space" has been left for adjacent technologies. Now with this new initiative we are starting to see this problem being addressed. Here is a quick summary of various attempts that have been made to address this problem so far. Hopefully the new Accellera committee will loo...

As we get to the end of an eventful 2013 and look forward to a great 2014, TeamCVC is at Manipal, a beautiful coastal town in the West coast of India. Surrounded by Arabian sea coast on one side and Western Ghats on the other, this is the ideal place for a peaceful research center and it is no co-incidence that the famous Manipal University is housed here. Coming to this town and conducting a 10-day boot-camp on SystemVerilog and UVM has been a pleasure so far as we have a young, talented, enthusiastic set of attendees. One thing that we continuously get asked during our VSV training sessions is – which SystemVerilog LRM to refer to? While the Google search reveals several PDFs, it gets quite confusing to a newcomer which one to pickup and refer to. In the past it used to be the due to “lack of reliable, legal reference” as the IEEE LRM was available at a cost. However the IEEE 1800-2012 LRM got released for free of cost, thanks to the IEEE GIT program. So go ahead and get a legal, ...

  Static design verification through thorough RTL analysis started several years ago, with early stage ones simply being “linters” and the later, advanced ones combining some of formal techniques as well. One of the most common complaints by RTL teams while using linters is the SNR – Signal-2-Noise Ratio of the endless set of errors/warnings from the tool. So much so that we have heard of customers giving up on linters, primarily those freebies/bundled with simulator ones. While it is true that some of the reported ones are indeed serious issues, the ROI (Return On Investment) of having RTL designers navigating through the ocean of messages is too little in many cases. OTOH there are clear set of issues that a good LINTer can spot for you quite easily, for instance see: Sledgehammer to crack a nut? – Use right tools for right class of design errors/bugs : http://www.cvcblr.com/blog/?p=377   Essentially it comes to the art of “Finding the needles in the haystack” and in...

In one of our recently concluded UVM training sessions at CVC a customer asked how easy is it to migrate an existing proven code base running with VMM to UVM. Since this is a very common situation, we at CVC have put together a detailed set of case studies and a half-a-day workshop on this topic. As a starting point we ask few simple questions to the customer on their code base so that we can provide an estimated effort involved in the migration. Invariably we start asking “Which VMM version do you run?” – and many are actually unaware :-( Here is a tiny piece of code that would get the answer right from your simulation: A small VMM-built-in utility class is provided as part of VMM named vmm_version . It has few interesting methods, First one being:     The first one displays the major-minor versions such as 1.11 and vendor name. Typically EDA vendors customize these opensource libraries to add debug features and at times to fix incompatibilities across implementations. ...

To all the ASIC Verification enthusiasts interested in pushing the limits beyond existing languages and methodologies, here is your chance to contribute and be part of the change. As many would be aware, IEEE 1647 standard defines Functional Verification language e . For over a decade e language has provided many advanced features for verification engineers that have recently been adopted to other languages such as SystemVerilog as well. The most recent one being “soft constraints” – see: http://www.cvcblr.com/blog/?p=629   And as more customers demand more features, the working group on e language has been busy adding new proposals. In our last group meeting we agreed on having four working sub-groups. http://www.eda.org/twiki/bin/view.cgi/P1647/Meeting78Minutes These are:- 1)      Temporal Working Group 2)      Messaging Working Group 3)      Types and Operators Working Group 4)    ...

Recently a customer sought a help on how does the UVM’s built-in scoreboard mechanism works, specifically in_order and algorithmic comparators. While he was able to use them well in his design, it when things fail – i.e. he potentially found a design bug he needed additional assistance in debug. By default the UVM framework provides compare() routine for transaction/ uvm_sequence_item . However unlike its predecessor HVLs such as the “E” language (IEEE 1647) or the OpenVera, System Verilog does not have the compare routine built-in to the language itself (for classes). Hence UVM adds it via base class and more. So when we have a transaction model such as: Now by virtue of inheritance, a handy method my_xactn::compare is available.  So one can use it to compare 2 objects of this type as shown below:   Note: in the above code snippet the return value of compare is unused, in actual code of-course you should assert it/throw an `uvm_error etc. Now, when we simulate this wit...

Recently an ABV early stage user/explorer realized it is little hard to get started with OVL-VHDL-Modelsim combination. It surprised us as  it would many others in the industry, having known how well folks at Mentor have been supporting OVL, VHDL etc. As valuable QVP partner with Mentor, we at TeamCVC decided to make it easier for end users. When we dug further we did realize it is not out-of-the-box. Hence we created a quick start example and uploaded it to our website. Feel free to grab it from here: http://www.cvcblr.com/downloads/ovl_vhdl.tgz   It is certainly a quick example just to demo the flow. Will add more soon. Here is the README for the example: CVC's OVL VHDL Example with Modelsim -------------------------------------- To compile and run OVL VHDL example in Questa/MTI follow this example We've used ovl_one_hot on a DUMMY signal, just to demo the flow. You need latest OVL 2.7 release. We've included a part of that in this tar ball To run ---...