Cadence® system design and verification solutions, integrated under our System Development Suite, provide the simulation, acceleration, emulation, and management capabilities.
Verification Suite Related Products A-Z
Cadence® digital design and signoff solutions provide a fast path to design closure and better predictability, helping you meet your power, performance, and area (PPA) targets.
Full-Flow Digital Solution Related Products A-Z
Cadence® custom, analog, and RF design solutions can help you save time by automating many routine tasks, from block-level and mixed-signal simulation to routing and library characterization.
Overview Related Products A-Z
Driving efficiency and accuracy in advanced packaging, system planning, and multi-fabric interoperability, Cadence® package implementation products deliver the automation and accuracy.
Cadence® PCB design solutions enable shorter, more predictable design cycles with greater integration of component design and system-level simulation for a constraint-driven flow.
An open IP platform for you to customize your app-driven SoC design.
Comprehensive solutions and methodologies.
Helping you meet your broader business goals.
A global customer support infrastructure with around-the-clock help.
24/7 Support - Cadence Online Support
Locate the latest software updates, service request, technical documentation, solutions and more in your personalized environment.
Cadence offers various software services for download. This page describes our offerings, including the Allegro FREE Physical Viewer.
The Cadence Academic Network helps build strong relationships between academia and industry, and promotes the proliferation of leading-edge technologies and methodologies at universities renowned for their engineering and design excellence.
Participate in CDNLive
A huge knowledge exchange platform for academia to network with industry. We are looking for academic speakers to talk about their research to the industry attendees at the Academic Track at CDNLive EMEA and Silicon Valley.
Come & Meet Us @ Events
A huge knowledge exchange platform for academia. We are looking for academic speakers to talk about their research to industry attendees.
Americas University Software Program
Join the 250+ qualified Americas member universities who have already incorporated Cadence EDA software into their classrooms and academic research projects.
EMEA University Software Program
In EMEA, Cadence works with EUROPRACTICE to ensure cost-effective availability of our extensive electronic design automation (EDA) tools for non-commercial activities.
Apply Now For Jobs
If you are a recent college graduate or a student looking for internship. Visit our exclusive job search page for interns and recent college graduate jobs.
Cadence is a Great Place to do great work
Learn more about our internship program and visit our careers page to do meaningful work and make a great impact.
Get the most out of your investment in Cadence technologies through a wide range of training offerings.
Overview All Courses Asia Pacific EMEANorth America
Instructor-led training [ILT] are live classes that are offered in our state-of-the-art classrooms at our worldwide training centers, at your site, or as a Virtual classroom.
Online Training is delivered over the web to let you proceed at your own pace, anytime and anywhere.
Exchange ideas, news, technical information, and best practices.
The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information.
It's not all about the technlogy. Here we exchange ideas on the Cadence Academic Network and other subjects of general interest.
Cadence is a leading provider of system design tools, software, IP, and services.
Get email delivery of the Cadence blog featured here
Using e macros can greatly improve your productivity by raising the level of abstraction at which these testbenches are created and used. With e macros, you can reduce the amount of code and simplify usage of code that needs to be used in several places in the testbench.
e macros are powerful code generators whose key benefit is their ability to extend the e language.
What is called "macro" in some other languages might be merely text replacement, such as replacing all occurrences of some text "A" with the text "B".
Macros in e can do this too, but they are capable of far more sophisticated things. These usages might be more complicated to debug, so Specman allows us to debug the generated code, instead of the macro definition code itself.
In this document, we are going to explore ways to debug macros in various stages of the simulation.
Let's consider the following test case:
Here we have a macro (define as) which simply creates a client object, and adds a client to a list of clients. (Note: The parentheses and quotation marks that enclose <x'string> prevent the preprocessor from considering all the parameters that come after the <x'string> declaration in the program code as part of the string.)
The addition of client to the list is done via another macro:
And the macro call is made here:
Specman parser gives clear error messages for syntax or parser issues at parsing time. For example, as seen below, we assign <x'name> (instead of <x'num>) to ‘it.num', but we do not have any such argument in the match expression.
This results in the following error:
The error here is pretty straightforward to fix. So let us correct the macro code (change line #14 to "it.num == <x'num>") and re-run it.
There could be cases where the macro parses correctly but encounters issues after it was expanded at load time. In such cases, the code is still not loaded.
We can use the "trace reparse" command to debug such issues. Let us again look at our example. The macro is modified a bit, as shown below:
Note: The code "it.name==<3>" at line #9 and 13 parses well, but will fail to load with an error that doesn't give much information (the message merely says that Specman expects a string for "i"). So let us use "trace reparse" (before load phase). This re-parses the code, and gives us the following helpful message from which we can understand the root cause of the error.
Run-time errors will occur on the expansion code that was created by the macro. In some cases, you might not get errors per se, but might see unintended or incorrect functionality. This is just like any other bug in your testbench, but the actual code is hidden under the macro definition.
Let's look how this reflects in our example. Once we are done loading and start to run the test, we get the following output:
For some reason, we generate NULL clients all the time. Is that expected behavior? Ummm...it doesn't seem so. So let's check what went wrong?
Like any other e code, we will use the source debugger to find the root cause:
1. Put a breakpoint on the macro call and then step into the macro call itself, so that it breaks when macro is called.
As seen above, a breakpoint is applied at line #37.
2. Run the simulation again after adding breakpoint. It automatically opens the source browser at breakpoint. If you step into the macro, the debugger will take you to the macro definition code:
3. Click on the macro debug mode button to select expansion mode. This will expand the macro code, to the real code Specman is running. Now you can keep on clicking ‘step into' button to see the flow of execution.
We can set a ‘watch' on x and x1 to see how they take the values. After setting a ‘watch', run it for few more steps and the Watch window should show following values.
This shows that the client ‘x' (NOT x1) was generated. Since x1 is empty, it keeps adding empty items to the list. This clarifies what was causing a NULL list of clients.
To summarize, macros in e are a very powerful tool. You need to know how to use them, and especially how to debug them. Having the correct tools makes this task much easier and intuitive, and prevents the frustration of debugging code you cannot even see.