PCI-SIG DevCon 2019 APAC tour has come to Tokyo and Taipei this year. The focus is predominantly around the latest updates for PCIe Gen 5 which its version 1.0 specification was just released this year in May.  A series of presentations provided by PCI-SIG on the day 1 with comprehensive information covering all aspects of Gen 5 specification, including protocol, logical, electrical, compliance updates. On the day 2 (only in Taipei), several member companies shared their view on Testing, PCB analysis and Signal integrity. The exhibit is also another spotlight of this event where the member companies showcased their latest PCIe solutions.

Presentation Track (Taipei), Exhibit (Tokyo), Exhibit (Taipei) 

Cadence, as the market leading PCIe IP vendor, participated APAC tour this year with bringing in its latest PCIe IP solution offering (Gen 5/4) to the region as well as showcasing two live demo setups in the exhibit floor. One setup is the PCIe software development kit (SDK) while the other is the Interop/compliance/debug platform. Both come with the Cadence PCIe Gen 4 hardware setup and its corresponding software kit.

The SDK can be used for Device Driver Development, Firmware Development, and for pre-silicon emulation as well. It supports Xtensa and ARM processor with Linux OS and it also equip with Ethernet interface which can be used for remote debugging. It also supports PCIe stress tests for Speed change, link enable/disable, entry/exist for lower power states, …etc. 

Cadence PCIe 4.0 Software Development Kit

The “System Interop/Compliance/Debug platform” was set up to test with multiple endpoint and System platforms. This system come with integrated Cadence software for basic system debug without the need for analyzer to perform the analysis, such as LTSSM History, TS1/TS2 transmitted/received with time stamp, Link training phases, Capturing Packet errors details, Capturing PHY TX/RX internal state machine details, ...etc.

Cadence PCIe System Interop/Compliance/Debug Platform

The year 2019 is certainly a "fruitful year" for the PCIe as more Gen 4 products are now available in the market, Gen 5 v1.0 specification got officially ratified, and PCI-SIG's revealing of Gen 6 specification development. We were glad to be part of this APAC tour with the chance to further introduce Cadence’s complete and comprehensive PCIe IP solution.

See you all next year in APAC again!

More Information

For more information on Cadence's PCIe IP offerings, see our PCI Express page.

For more information on PCIe in general, and on the various PCI standards, see the PCI-SIG website.

Related Posts

• Blog: Did You “Stress Test” Yet? Essential Step to Ensure a Quality PCIe 4.0 Product
• Blog: PCIe Gen4: It’s Official, We’re Compliant
• Blog: PCIe 3.0 Still Shines While PCIe Keeps Evolving
• Blog: The PCIe 4.0 Era Continues at PCI-SIG Developers Conference 2016

I’m writing this on August 15. It is our Independence Day. A young Kashmiri Muslim told me in Srinagar a few months ago that this is the day on which everyone there tries to stay indoors. This is not because the people support Pakistan, but because they are most suspect on August 15. You are questioned, searched, and locked. If any of the readers have had a chance to view Sanjay Kak’s powerful documentary Jashn-e-Azadi (How We Celebrate Freedom) you’ll see how Sanjay, coming in to Srinagar for a visit around Independence Day, is struck by the fact that the only people present for the ceremony are the cops and members of the armed forces. (That’s Rave Out #1. For Jashn-e-Azadi.)

Last week’s announcement of the Indian Express-CNN/IBN poll, that an overwhelming majority of Kashmiris in the valley want azadi, also underlines the importance of a genuine rethinking on the question of independence rather than empty, nationalist sabre-rattling. (Anyway, that’s Rave Out #2. For Indian Express and CNN/IBN, as well as the good folk at CSDS who designed the poll.)

This is a good day for re-opening the pages of 13 December: A Reader, in which thirteen writers and journalists point out the injustice involved in the quick media-lynching of SAR Geelani and the denial of a fair trial to Afzal Guru. (This would be Rave Out #3, for the book, although wouldn’t it be great if the book weren’t needed?)

Rave Out © 2007 IndiaUncut.com. All rights reserved.
India Uncut * The IU Blog * Rave Out * Extrowords * Workoutable * Linkastic

I could barely recognize Ben Foster in 3:10 to Yuma, but I was blown away just the same by him as in his star making turn from Hostage. What makes Foster so special in Yuma?

Yuma contains two of Hollywood’s finest: Russell Crowe and Christian Bale. Bale is excellent, Crowe a little too relaxed to be cock-sure-dangerous. Both are unable to provide the powder-keg relationship that the movie demands.

Into this void steps Ben Foster. He plays Charlie Prince, sidekick to Crowe’s dangerous and celebrated outlaw Ben Wade. When Wade is captured, Prince is infuriated. He initiates an effort suffused with desperate passion to rescue his boss.

Playing Prince with a mildly effeminate gait, Foster quickly becomes the movie’s beating heart. What struck me in particular was that Foster was able to balance method acting with just plain good acting. He plays his character organically but isn’t above drawing attention with controlled staginess.

Gradually, Foster’s willingness to control a scene blend in with that of Prince’s. Is the character manipulating his circumstances in the movie or is it the actor playing a fine hand? Foster is so entertaining, the answer is immaterial.

Rave Out © 2007 IndiaUncut.com. All rights reserved.
India Uncut * The IU Blog * Rave Out * Extrowords * Workoutable * Linkastic

Formal verification is a complex technology that has traditionally required experts or specialized teams who stood apart from the IC design and verification flow. Taking a different approach, a new release of the Cadence JasperGold formal verification platform (June 8, 2015) provides formal techniques that complement simulation, emulation, and debugging in the form of “Apps” or under-the-hood solutions that any design or verification engineer can use.

JasperGold was the initial (in fact only) product of Jasper Design Automation, acquired by Cadence in 2014. Jasper pioneered the formal Apps concept several years ago. While the company had previously sold JasperGold as a one-size-fits-all solution, Jasper began selling semi-automated JasperGold Apps that solved specific problems using formal analysis technology.

The new release is the next generation of JasperGold and will be available later this month. It includes three major improvements over previous Cadence and Jasper formal analysis offerings:

• A unified Cadence Incisive and JasperGold formal verification platform delivers up to 15X performance gain over previous solutions.
• JasperGold is integrated into the Cadence System Development Suite, where it provides formal-assisted simulation, emulation, and coverage. As a result, System Development Suite users can find bugs three months earlier than existing verification methods.
• JasperGold’s formal analysis engines are integrated with the recently announced Indago debug platform, automating root cause analysis and on-the-fly, what-if exploration.

Best of Both Formal Verification Worlds

Taking advantage of technologies from both Cadence and Jasper, the new JasperGold represents a “best of both worlds” solution, according to Pete Hardee, product management director at Cadence. This solution combines technologies from the Cadence Incisive Enterprise Verifier and Incisive Formal Verifier with JasperGold formal analysis engines.

For example, to ease migration from Incisive formal tools, Cadence has integrated an Incisive common front end into the JasperGold apps platform. Jasper formal engines can run within the Incisive run-time environment. Cadence has also brought some selected Incisive formal engines into JasperGold.

As shown to the right, the JasperGold platform supports both the existing JasperGold front-end parser and the Incisive front-end parser. Hardee observed that this dual parser arrangement simplifies migration from Incisive formal tools to JasperGold, and provides a common compilation environment for people who want to use JasperGold with Incisive simulation. Further, the common run-time environment enables formal-assisted simulation.

The combination of JasperGold engines and Incisive engines supports two use models for formal analysis: formal proofs and bug hunting. In the first case, formal engines try all combinations of inputs without a testbench. The test is driven by formal properties written in languages such as SVA (SystemVerilog assertions) or PSL (Property Specification Language). Completion of a property is exhaustive proof that something can or cannot happen. This provides a “much stronger result” than simulation, Hardee said.

He also noted that formal analysis doesn’t necessarily require that all properties are completed. “You can get a lot of value even if proofs don’t complete,” he said. “Proofs that run deep enough to find bugs are just fine.”

Bug hunting involves random searches, and JasperGold bug hunting engines are very fast. However, these engines don’t necessarily use the most optimal path to get to a bug. So, Cadence engineers brought a constraint solver from Incisive and integrated it into JasperGold. “It looks at the constraints in the environment and gives you a better starting point,” Hardee said. “It takes more up-front time, but once you’ve done that the bug hunting engines can actually take a shorter path and find a bug a lot quicker.”

Another new JasperGold capability from the Incisive Formal Verifier is called “search pointing.” This uses simulation to penetrate deeply into the state space, and then kicks off a random formal search from a given point that you’ve reached in simulation. This technique makes it possible to find bugs that are very deep in the design.

It is probably clear by now that a number of different formal “engines” may be required to solve a given verification problem. Traditionally, a formal tool (or user) will farm a problem out to many engines and see which one works best. To put more intelligence into that process, Cadence launched the Trident “multi-cooperating engine” a couple of years ago. That has now been brought into JasperGold, where it helps “orchestrate” the engines according to what will work best for the design. This is a big part of the reason for the 15X speedup noted earlier in this post.

Integration with System Development Suite

The Cadence System Development Suite is an integrated set of hardware/software development and verification engines, including virtual prototyping, Incisive simulation, emulation, and FPGA-based prototyping. As shown below, JasperGold technology is integrated into the System Development Suite in several places, including formal-assisted debug, formal-assisted verification closure, formal-assisted simulation, formal-assisted emulation, and the Incisive vManager verification planning tool.

Formal-assisted emulation sounds like it should be easy, especially since Cadence has both accelerated verification IP (VIP) and assertion-based VIP. However, there’s a complication. Accelerated VIP represents less verification content than simulation VIP, because you have to remove many checkers to get VIP to compile on a Palladium emulator. That’s because the Palladium requires synthesizable code.

What you can do, however, is use assertion-based VIP in “snoop mode” as shown below. Assertion-based VIP coded in synthesizable SystemVerilog can replace the missing checkers in accelerated VIP. In this diagram, everything in the green box is running in the emulator and is thus completely accelerated.

Another example of formal-assisted emulation has to do with deep traces. As Hardee noted, emulation will produce very long traces, and it can be very difficult to find a point of interest in the trace and determine what caused an error. With formal-assisted emulation, users can find interesting events within the traces and create properties that mark them, so a debugger can find these events and trace back to the root cause.

Formal-assisted verification closure is available with the new JasperGold release. This is possible because you can use the vManager product to determine which tasks were completed by formal engines. It’s important information for verification managers who are not used to formal tools, Hardee noted.

Another aspect of formal-assisted verification closure is the JasperGold Unreachability Analysis (UNR) App, which can save simulation users weeks of time and effort. This App takes in the simulation coverage database and RTL, and automatically generates properties to explore coverage holes and determine if holes are reachable or unreachable. The App then generates an unreachable coverage point database. If the unreachable code does something useful, there’s a bug in the design or the testbench; if not, you don’t have to worry about it. The diagram below shows how it works.

Formal-Assisted Debugging

The third major component of the JasperGold announcement is the integration of formal analysis into the Indago debugging platform. As shown below, this platform has several apps, including the Indago Debug Analyzer. Two formal debug capabilities from the Jasper Visualize environment have been added to the the Indago Debug Analyzer:

• Highlight Relevant Logic: This highlights the “cone of influence,” or the logic that is involved in reaching a given point
• Why: This button highlights the immediate causes for a given event, and allows users to trace backwards in time

More formal capabilities will come with the Indago Advanced Debug Analyzer app, scheduled for release towards the end of 2015. This includes Quiet Trace, a Jasper capability that reduces trace activity to transactions relevant to an event. Also, a what-if analysis allows on-the-fly trace editing and recalculation to explore effects and sensitivities, without having to re-compile and re-execute the simulation.

Finally, Cadence has a Superlint flow that is now fully integrated with the JasperGold Visualize debugger. This two-tiered flow includes a basic lint capability as well as automated formal analysis based on the JasperGold Structural Property Synthesis app. “This could be a very good entry point for designers to start using formal,” Hardee said.

“Formal is taking off,” Hardee concluded. “People are no longer talking about return on investment for formal—they have established that. Now they’re supporting a proliferation of formal in their companies such that a wider set of people experience the benefit from that proven return on investment.”

Further information is available at the JasperGold Formal Verification Platform (Apps) page.

Richard Goering

Related Blog Posts

- JUG Keynote—How Jasper Formal Verification Technology Fits into the Cadence Flow

- Why Cadence Bought Jasper—A New Era in Formal Analysis

- Q&A: An R&D Perspective on Formal Verification—Past, Present and Future

In 1985, as a relatively new editor at Computer Design magazine, I was asked to go forth and cover a new business called CAE (computer-aided engineering). I knew nothing about it, but I had been writing about design for test, so there seemed to be somewhat of a connection. Little did I know that “CAE” would turn into “EDA” and that I’d write about it for the next 30 years, for Computer Design, EE Times, Cadence, and a few others.

Now that I’m about to retire, I’m looking back over those 30 years. What a ride it has been! By the numbers I covered 31 Design Automation Conferences (DACs), hundreds of new products, dozens of acquisitions and startups, dozens of lawsuits, and some blind alleys that didn’t work out (like “silicon compilation”). Chip design went from gate arrays and PLDs with a few thousand gates to processors and SoCs with billions of transistors.

In 1985 there were three big CAE vendors – Daisy Systems, Mentor Graphics, and Valid Logic. All sold bundled packages that included workstations and CAE software; in fact, Daisy and Valid designed and manufactured their own workstations. In the early 1980s a workstation with schematic capture and gate-level logic simulation might have set you back $120,000. In 1985 OrCAD, now part of Cadence, came out with a $500 schematic capture package running on IBM PCs.

Cadence and Synopsys emerged in the late 1980s, and by the 1990s the EDA industry was pretty much a software-only business (apart from specialized machines like simulation accelerators). Since the early 1990s the “big three” EDA vendors have been Cadence, Synopsys, and Mentor, giving the industry stability but allowing for competition and innovation.

Here, in my view, are some of the highlights that occurred during the past 30 years of EDA.

EDA is a Highlight

The biggest highlight in EDA is the existence of a commercial EDA industry! Marching hand in hand with the fabless semiconductor revolution, commercial EDA made it possible for hundreds of companies to design semiconductors, as opposed to a small handful that could afford large internal CAD operations and fabs. With hundreds of semiconductor companies as opposed to a half-dozen, there’s a lot more creativity, and you get the level of sophistication and intelligence that you see in your smartphone, video camera, tablet, gaming console, and car today.

CAE + CAD = EDA. This is not just a terminology issue. By the mid-1980s it became clear that front-end design (CAE) and physical design (CAD) belonged together. The big CAE vendors got involved in IC and PCB CAD, and presented increasingly integrated solutions. People got tired of writing “CAE/CAD” and “EDA” was born.

The move from gate-level design to RTL. This move happened around 1990, and in my view this is EDA’s primary technology success story during the past 30 years. Moving up in abstraction made the design and verification of much larger chips possible. Going from gate-level schematics to a hardware description language (HDL) revolutionized logic design and verification. Which would you rather do – draw all the gates that form an adder, or write a few lines of code and let a synthesis tool find an adder in your chosen technology?

Two developments made this shift in design possible. One was the emergence of commercial RTL synthesis (or “logic synthesis”) tools from Synopsys and other companies, which happened around 1990. Another was the availability of Verilog, developed by Gateway Design Automation and purchased by Cadence in 1989, as a standard RTL HDL. Although most EDA vendors at the time were pushing VHDL, designers wanted Verilog and that’s what most still use (with SystemVerilog coming on strong in the verification space).

IC functional verification underwent huge changes in the late 1990s and early 2000s, largely due to new technology developed by Verisity, which was acquired by Cadence in 2005. Before Verisity, verification engineers were writing and running directed tests in an ad-hoc manner. Verisity introduced or improved technologies such as pseudo-random test generation, coverage metrics, reusable verification IP, and semi-automated verification planning. The Verisity “e” language became a widely used hardware verification language (HVL).

The biggest way that EDA has expanded its focus has been through semiconductor IP. Today Synopsys and Cadence are leading providers in this area. Thanks to the availability of design and verification IP, many SoC designs today reuse as much as 80% of previous content. This makes it much, much faster to design the remaining portion. While IP began with fairly simple elements, today commercially available IP can include whole subsystems along with the software that runs on them. With IP, EDA vendors are providing not only design tools but design content.

Finally, the EDA industry has done an amazing job of keeping up with SoC complexity and with advanced process nodes. Thanks to intense and early collaboration between foundries, IP, and EDA providers, tools and IP have been ready for process nodes going down to 10nm.

Where Does ESL Fit?

In some ways, electronic system level (ESL) design is both a lowlight and a highlight. It’s a lowlight because people have been talking about it for 30 years and the acceptance and adoption have come very slowly. ESL is a highlight because it’s finally starting to happen, and its impact on design and verification flows could be dramatic. Still, ESL is vaguely defined and can be used to describe almost anything that happens at a higher abstraction level than RTL.

High-level synthesis (HLS) is an ESL technology that is seeing increasing use in production environments. Current HLS tools are not restricted to datapaths, and they produce RTL code that gives better quality of results than hand-written RTL. Another ESL methodology that’s catching on is virtual prototyping, which lets software developers write software pre-silicon using SystemC models. Both HLS and virtual prototyping are made possible by the standardization of SystemC and transaction-level modeling (TLM). However, it’s still not easy to use the same SystemC code for HLS and virtual prototyping.

And Now, Some Lowlights

Every new industry has some twists and turns, and EDA is no exception. For example, the EDA industry in the 1980s and 1990s sparked a lot of lawsuits. At EE Times my colleagues and I wrote a number of articles about EDA legal disputes, mostly about intellectual property, trade secrets, or patent issues. Over the past decade, fortunately, there have been far fewer EDA lawsuits than we had before the turn of the century.

Another issue that was troublesome in the 1980s and 1990s was so-called “standards wars.” These would occur as EDA vendors picked one side or the other in a standards dispute. For example, power intent formats were a point of conflict in the early 2000s, but the Common Power Format (CPF) and the Unified Power Format (UPF) are on the road to convergence today with the IEEE 1801 effort. As mentioned previously, Verilog and VHDL were competing for adoption in the early 1990s. For the most part, Verilog won, showing that the designer community makes the final decision about which standards will be used.

How on earth did there get to be something like 30 DFM (design for manufacturability) companies 10-12 years ago? To my knowledge, none of these companies are around today. A few were acquired, but most simply faded away. A lot of investors lost money. Today, VCs and angel investors are funding very few EDA or IP startups. There are fewer EDA startups than there used to be, and that’s too bad, because that’s where a lot of the innovation comes from.

Here’s another current lowlight -- not enough bright engineering or computer science students are joining EDA companies. They’re going to Google, Apple, Facebook, and the like. EDA is perceived as a mature industry that is still technically very difficult. We need to bring some excitement back into EDA.

Where Is EDA Headed?

Now we come to what you might call “headlights” and look at what’s coming. My list includes:

• System Design Enablement. This term has been coined by Cadence to describe a focus on whole systems or end products including chips, packages, boards, embedded software, and mechanical components. There are far more systems companies than semiconductor companies, leaving a large untapped market that’s looking for solutions.
• New frontiers for EDA. At a 2015 Design Automation Conference speech, analyst Gary Smith suggested that EDA can move into markets such as embedded software, mechanical CAD, biomedical, optics, and more.
• Vertical markets. EDA has until now been “horizontal,” providing the same solution for all market segments. Going forward, markets like consumer, automotive, and industrial will have differing needs and will need optimized tools and IP.
• Internet of Things. This is a current buzzword, but the impact on EDA remains uncertain. Many IoT devices will be heavily analog, use mature process nodes, and be dirt cheap. Lip-Bu Tan, Cadence CEO, recently pointed out that the silicon percentage of IoT revenue will be small and that a lot of the profits will be on the service side.

Moving On

For the past six years I’ve been writing the Industry Insights blog at Cadence.com. All things change, and with this post comes a farewell – I am retiring in late June and will be pursuing a variety of interests other than EDA. I’ll be watching, though, to see what happens next in this small but vital industry. Thanks for reading!

Richard Goering

Hi,

I'm a newbie and I'm working on a mixed-signal chip in Innovus. I've got a few analog LEF files that I've imported into my floorplan as macros.

My chip has got two power domains - VCC and VBAT.

One of the macro in the VBAT domain uses VBAT and GND as power rails myloweslife.com.

On doing Special-Route, I've got a lot of minute power rails for the standard cells, as expected.

But, the VBAT power rails are not getting extended till the outer power rings. Only the GND rails are correctly getting extended till the outer power rings.

A screen shot is attached for reference.

Thanks for any help

Hi,

I'm a newbie and I'm working on a mixed-signal chip in Innovus. I've got a few analog LEF files that I've imported into my floorplan as macros.

My chip has got two power domains - VCC and VBAT.

One of the macro in the VBAT domain uses VBAT and GND as power rails KrogerFeedback.com.

On doing Special-Route, I've got a lot of minute power rails for the standard cells, as expected.

But, the VBAT power rails are not getting extended till the outer power rings. Only the GND rails are correctly getting extended till the outer power rings.

A screen shot is attached for reference.

Thanks for any help

I have been working on a an ASA 17.2 project for the last 6 months.

When I go to Project --> Settings, the settings window does not open. 

The tool indicates that a window is open, as I cannot click on anything else in the project. But it does not show the Settings window.

This has been happening only for the last 2 months. Before that it was working fine.

If I send the project to my colleague, the settings window shows up for him.

It's been a while since you've heard from me...it has been a busy year for sure. One of the reasons I've been so quiet is that I was part of a team working diligently on our latest best kept secret: The MMSIM 12.1.1/MMSIM 13.1 Documentation has...(read more)

Hi All, Here's another great new feature that I've found very helpful... Broadband SPICE is a new tool for S-parameter simulation in Spectre RF. In the MMSIM13.1.1 ( MMSIM13.1 USR1) release (now available on http://downloads.cadence.com), a...(read more)

Last year, I wrote a blog post entitled Modeling Oscillators with Arbitrary Phase Noise Profiles . We now have an easier way to do this. Starting in MMSIM 13.1 , you can specify the phase noise as an instance parameter in Spectre sources, including...(read more)

Hello Spectre RF Users, Next week is my all time favorite technical conference - the International Microwave Symposium IMS2016 , May 22-27 in San Francisco, CA at the Moscone Center. If you're at the conference, please stop by the Cadence booth and...(read more)

Did you check out the new Pnoise and Hbnoise Choosing Analyses forms in the MMSIM 15.1 and IC6.1.7 /ICADV12.2 releases? These forms have been significantly improved and simplified. The Direct Plot Form has also been enhanced and is much easy to use....(read more)

Hello Spectre Users, Simulating S-parameters in a time domain (transient, periodic steady state) simulator has been and continues to be a challenge for many analog and RF designers. I'm often asked: What is required in order to achieve accurate...(read more)

Hi All, If you were unable to attend IMS 2017 in June 2017, the IMS MicroApp “7 Habits of Highly Successful S-Parameters” is on our Cadence website. On Cadence Online Support , the in-depth AppNote is here: 20466646 . Best regards, Tawna...(read more)

When I place a pcell and do not change the W parameter (default is used) the value is not saved in the OA cell property.

When I change the default value of the super master now, the old pcell will get the new default value automatically because there is nothing saved inside the OA cell for this parameter.

Do you have any Idea, that how we can save the default values in the OA cell properties so that this value doesn't get updated if the default values are updated in the new PDKs

I could not find info about the highlight shapes/layers in the cadence doc directory, forum, support library.

I have a script that creates highlight shapes on the y* drawing layer.

My understand is the highlight is a virtual shape. The shapes go away when the cadence session is closed or when you close data of that cellview if it is not global.

If they are vitual shapes it would be okay to use valid or process layers when I create the highlight set with geCreateHilightSet.

Ex: ( The command I use to create the hiighlight set       geCreateHilightSet(cv list(lay purp) nil) )

Current y0-9 drawing 

To N-P_implant drawing

Paul

Hi there,

I'm running a transient simulation, and I want to get all instances with model implementation hisim_hv because after that I want to process the data and to adjust some parameters for this kind of devices before dumping the values.

What is the easiest/fastest way to get those instances in skill/ocean?

What I did until now: 

- save the final OP of the simulation and then in skill

openResults()
selectResults('tranOp)
report(?type "hisim_hv" ?param "vgs")

Output seems to be promising, and looks like I can redirect it to a file and after that I have to parse the file.

Is there other simple way? I mean to not save data to file and to parse it.

Eventually having an instance name, is it possible to get the model implementation (hsim_hv, bsim4, etc..)? 

Best Regards,

Marcel

It’s been quite a long 5-year journey building and deploying Performance Analysis, Verification, and Debug capabilities for Arm-based SoCs. We worked with some of the smartest engineers on the planet. First with the engineers at Arm, with whom we...(read more)

Here we conclude the blog series and highlight the results of Mediatek 's use of Cadence Perspec™ System Verifier for their SoC level verification. In case you missed it, Part 1 of the blog is here , and Part 2 of the blog is here . One of their key...(read more)

It’s now official: Perspec System Verifier is rated the #1 product in the #1 category of Portable Stimulus, according to the 2017 EDA User Survey published on Deepchip.com. There were 33 user responses in favor of Perspec as the #1 tool, and dr...(read more)

It’s always good to hear what real users think of products. Here is a very detailed review (~4000 words) by an Anonymous user, nick named Ant-Man (from the movie). Overall it’s a very strong endorsement of Perspec, and summarize...(read more)

There’s nothing like the heat of a DAC demo to stress new technology and the engineers behind it! Such was the case at DAC 2018 at the new locale of Moscone Center West, San Francisco. Cadence and AMIQ were two of several vendors who announced ...(read more)

Cadence pulled a fast one at DAC 2018, almost like a bait and switch. We advertised a hands-on workshop to learn about Accellera Portable Stimulus Specification (PSS) v1.0. But we made participants compete head to head, for prizes, and their pride! T...(read more)

Cadence continues to be a leader in SoC verification and has expanded our industry investment in Accellera portable stimulus language standardization. Some customers have expressed reservations that portable stimulus requires the effort of learn...(read more)

Is there any way I can find duplicated shapes?

I would like to find two or more shapes are identical and they are placed in the same location.

Hi, I want to add values to components in my SiP design such as 1nF or 15nH. There is already in existence a COMP_VALUE property reserved for this as shown during BOM generation. This property is not visible under the Edit/Properties dialog for component or symbol find filters. We have already created user properties called COMP_MFG and COMP_MFG_PN that it editable at a component level. When we try to add COMP_VALUE it is reported as a reserved name in Cadence but this name is not listed in the properties dialog. Is there a way to turn on the visibility and editablility of this or other hidden reserved Cadence property names? How can I assign a string value to the COMP_VALUE property?

Thanks

Hi all,

I have a question regarding the manufacture : how to check a cluster of same net vias spacing, with have no shape or cline covered

Have you ever manufactured a printed circuit board (PCB) without analyzing all the routed signal traces? Most designers will say “yes, all the time.” Trace widths and spacing are set by constraints,...

[[ Click on the title to access the full blog on the Cadence Community site. ]]

Those who work in the IC Packaging design space have some unique challenges. We bridge between the IC design world (90/45-degree traces with rectangular and octagonal pins) and the PCB domain...

[[ Click on the title to access the full blog on the Cadence Community site. ]]

Our customers’ tests have become more complex, longer, and consume more resources than before. This increases the need to optimize the regression while not compromising on coverage. Some advanced...

[[ Click on the title to access the full blog on the Cadence Community site. ]]

Cadence ® Spectre ® AMS Designer is a high-performance mixed-signal simulation system. The ability to use multiple engines, and drive from a variety of platforms enables you to "rev...

[[ Click on the title to access the full blog on the Cadence Community site. ]]

In the former blog about Python and Specman: Specman: Python Is here!, we described the technical information around Specman-Python integration. Since Python provides so many easy to use existing libraries in various fields, it is very tempting to leverage these cool Python apps.

Coverage has always been the center of the verification methodology, however in the last few years it gets even more focus as people develop advanced utilities, usually using Machine Learning aids. Anyhow, any attempt to leverage your coverage usually starts with some analysis of the behavior and trends of some typical tests. Visualizing the data makes it easier to understand, analyze, and communicate. Fortunately, Python has many Visualization libraries.

In this blog, we show an example of how you can use the plotting Python library (matplotlib) to easily display coverage information during a run. In this blog, we use the Specman Coverage API to extract coverage data, and a Python module to display coverage grades interactively during a single run and the way to connect both.

Before we look at the example, if you have read the former blog about Specman and Python and were concerned about the fact that python3 is not supported, we are glad to update that in Specman 19.09, Python3 is now supported (in addition to Python2).

The Testcase
Let’s say I have a stable verification environment and I want to make it more efficient. For example: I want to check whether I can make the tests shorter while hardly harming the coverage. I am not sure exactly how to attack this task, so a good place to start is to visually analyze the behavior of the coverage on some typical test I chose. The first thing we need to do is to extract the coverage information of the interesting entities. This can be done using the old Coverage API. 

Coverage API
Coverage API is a simple interface to extract coverage information at a certain point. It is implemented through a predefined struct type named user_cover_struct. To use it, you need to do the following:

1. Define a child of user_cover_structusing like inheritance (my_cover_struct below).
2. Extend its relevant methods (in our example we extend only the end_group() method) and access the relevant members (you can read about the other available methods and members in cdnshelp).
3. Create an instance of the user_cover_structchild and call the predefined scan_cover() method whenever you want to query the data (even in every cycle). Calling this method will result in calling the methods you extended in step 2.  

 The code example below demonstrates these three steps. We chose to extend the end_group() method and we keep the group grade in some local variable. Note that we divide it by 100,000,000 to get a number between 0 to 1 since the grade in this API is an integer from 0 to 100,000,000. 

Pass the Data to a Python Module
After we have extracted the group grade, we need to pass the grade along with the cycle and the coverage group name (assuming there are a few) to a Python module. We will take a look at the Python module itself later. For now, we will first take a look at how to pass the information from the e code to Python. Note that in addition to passing the grade at certain points (addVal method), we need an initialization method (init_plot) with the number of cycles, so that the X axis can be drawn at the beginning, and end_plot() to mark interesting points on the plot at the end. But to begin with, let’s have empty methods on the Python side and make sure we can just call them from the e code.

 # plot_i.py
def init_plot(numCycles):
    print (numCycles)
def addVal(groupName,cycle,grade):
    print (groupName,cycle,grade)
def end_plot():
    print ("end_plot") 

And add the calls from e code:

 Before running this, note that you need to ensure that Specman finds the Python include and lib directories, and Python finds our Python module. To do this, you need to define a few environment variables: SPECMAN_PYTHON_INCLUDE_DIR, SPECMAN_PYTHON_LIB_DIR, and PYTHONPATH. 

 The Python Module to Draw the Plot
After we extracted the coverage information and ensured that we can pass it to a Python module, we need to display this data in the Python module. There are many code examples out there for drawing a graph with Python, especially with matplotlib. You can either accumulate the data and draw a graph at the end of the run or draw a graph interactively during the run itself- which is very useful especially for long runs.

Below is a code that draws the coverage grade of multiple groups interactively during the run and at the end of the run it prints circles around the maximum point and adds some text to it. I am new to Python so there might be better or simpler ways to do so, but it does the work. The cool thing is that there are so many examples to rely on that you can produce this kind of code very fast.

 In the example we used, we had two interesting entities: packet and state_machine, thus we had two equivalent coverage groups. When running our example connecting to the Python module, we get the following graph which is displayed interactively during the run.

When analyzing this specific example, we can see two things. First, packet gets to a high coverage quite fast and significant part of the run does not contribute to its coverage. On the other hand, something interesting happens relating to state_machine around cycle 700 which suddenly boosts its coverage. The next step would be to try to dump graphic information relating to other entities and see if something noticeable happens around cycle 700.

To run a complete example, you can download the files from: https://github.com/okirsh/Specman-Python/

Do you feel like analyzing the coverage behavior in your environment? We will be happy to hear about your outcomes and other usages of the Python interface.

Orit Kirshenberg
Specman team

We're happy to have guest blogger Thorsten Dworzak, Principal Consultant at Verilab GmbH, describe how he added Specman/e syntax to Sublime Text 3:

According to the 2018 StackOverflow Developer Survey, the popularity of development environments (IDEs, Text Editors) among software developers shows the following ranking:

1. Visual Studio Code 34.9%
2. Visual Studio 34.3%
3. Notepad++ 34.2%
4. Sublime Text 28.9%
5. Vim 25.8%
6. IntelliJ 24.9%
7. Android Studio 19.3%
8. (DVT) Eclipse 18.9%
9. …

15. Emacs 4.1%

Of these, only Vim, (DVT) Eclipse, and Emacs support editing in e-language (at least, last time I checked). Kate, which comes with KDE and also has a Specman mode, is not on this list.

I started using Sublime Text 3 some time ago. It offers packages that support a number of programming languages.

Though there is an e-language syntax available from Tsvi Mostovicz, it is unfinished work, and there are many syntactic constructs are missing. So, I created a fork of his project and finished it (it will eventually be merged back here).

It is a never-ending task because my code base for testing is limited and e is still undergoing development. The project is available through ST3's Package Control and you can contribute to it via Github.

I am eagerly waiting for your pull requests and/or comments and contributions!

Our customers’ tests have become more complex, longer, and consume more resources than before. This increases the need to optimize the regression while not compromising on coverage.

Some advanced customers of Specman use Machine Learning based solutions to optimize the regressions while some use simpler solutions. Based on a request of an advanced customer, we added a new Coverage API in Specman 19.09 called Coverage Callback. In 20.03, we have further enhanced this API by adding more options. Now there are two Coverage APIs that provide coverage information during the run (the old scan_cover API and this new Callback API). This blog presents these two APIs and compares between them while focusing on the newer one.

Before we get into the specifics of each API, let’s discuss what is common between these APIs and why we need them. Typically, people observe the coverage model after the test ends, and get to know the overall contribution of the test to the coverage. With these two APIs, you can observe the coverage model during the test, and hence, get more insight into the test progress.

Are you wondering about what you can do with this information? Let’s look at some examples.

1. Recognize cases when the test continues to run long after it already reached its coverage goal.
2. View the performance of the coverage curve. If a test is “stuck” at the same grade for a long time, this might indicate that the test is not very good and is just a waste of resource.

These analyses can be performed in the test itself, and then a test can decide to either stop the run, or change something in it configuration, or – post run. You can also present them visually for some analysis, as shown in the blog: Analyze Your Coverage with Python.

scan_cover API (or “Scanning the Coverage Model”)

With this API you can get the current status for any cover group or item you are interested in at any point in time during the test (by calling scan_cover()). It is very simple to use; however it has performance penalty. For getting the coverage grade of any cover group during the test, you should
1. Trigger the scan_cover at any time when you want the coverage model to be scanned.
2. Implement the scan_cover related methods, such as start_item() and end_bucket(). In these methods, you can query the current grade of group/item/bucket.
The blog mentioned earlier: Analyze Your Coverage with Python describes the details and provides an example.

Callback API

The Callback API enables you to get a callback for a desired cover group(s), whenever it is sampled. This API also provides various query methods for getting coverage related information such as what the current sampled value is. So, in essence, it is similar to scan_cover API, but as the phrase says: “same same but different”:

1. Callback API has almost no performance penalty while scan_cover API does.
2. Callback API contains a richer set of query methods that provide a lot of information about the current sampled value (vs just the grade with scan_cover).
3. Using scan_cover API, you decide when you want to query the coverage information (you call scan_cover), while with the Callback API you query the coverage information when the coverage is sampled (from do_callback). So, scan_cover gives you more flexibility, but you do need to find the right timing for this call.

There is no absolute advantage of either of these APIs, this only depends on what you want to do.  

Callback API details

The Callback API is based on a predefined struct called: cover_sampling_callback. In order to use this API, you need to:

1. Define a struct inheriting cover_sampling_callback (cover_cb_save_data below)
   1. Extend the predefined do_callback() method. This method is a hook being called whenever any of the cover groups that are registered to the cover_sampling_callback instance is being sampled.
   2. From do_callback() you can access coverage data by using queries such as: is_currently_per_type(), get_current_group_grade() and get_current_cover_group() (as in the example below) and many more such as: get_relevant_group_layers() and get_simple_cross_sampled_bucket_name().
2. Register the desired cover group(s) to this struct instance using the register() method.

Take a look at the following code:

// Define a coverage callback.
// Its behavior – print to screen the current grade.
struct cover_cb_save_data like cover_sampling_callback {
    do_callback() is only {
       // In this example, we care only about the per_type grade, and not per_instance
       if is_currently_per_type() {           
            var cur_grade : real = get_current_group_grade();
            sys.save_data (get_current_cover_group().get_name(), cur_grade);
        };//if
    };//do_callback()
};// cover_cb_send_data


extend sys {
    !cb : cover_cb_save_data;

   // Instantiate the coverage callback, and register to it two of my coverage groups
    run() is also {
       cb  = new  with {
        var gr1:=rf_manager.get_struct_by_name("packet").get_cover_group("packet_cover");
        .register(gr1);
        var gr2:=rf_manager.get_struct_by_name("sys").get_cover_group("mem_cover");
       .register(gr2);
       };//new  
    };//run()

  save_data(group_name : string, group_grade : real) is {
        //here you either print the values to the screen, update a graph you show or save to a db 
  };// save_data
};//sys

In the blog Analyze Your Coverage with Python mentioned above, we show an example of how you can use the scan_cover API to extract coverage information during the run, and then use the Specman-Python API to display the coverage interactively during the run (using plotting Python library - matplotlib). If you find this usage interesting and you want to use the same example, by the Callback API instead of the scan_cover API, you can download the full example from GIT from here: https://github.com/efratcdn/cover_callback.

Specman Team

Have you ever manufactured a printed circuit board (PCB) without analyzing all the routed signal traces? Most designers will say “yes, all the time.” Trace widths and spacing are set by constraints, and many designers simply don’t h...(read more)

Hi,
I am new to the circuit design and troubleshooting. My project is to design a trans-impedance amplifier using Cadence that can amplify a signal coming from a photodiode. I started out with the regulated cascode configuration as shown in the circuit below. I look at the frequency response using AC simulation and it looks like a high pass (/net 5). The results doesn ot show any gain (transient response), or expected low-pass roll-off in the AC response.

First thing, I looked into the operating regions of the MOSFETs and adjusted the input dc voltage of the Vsin to 0.5 to make sure that the T0, T1 mosfets are in saturation(checked this with the print->dc operating points). Beyond this point, I am not sure on how to proceed and interpret the results to make changes. Any help would be greatly appreciated.

Thanks,

-Rakesh.

Hello, i need to test the  parameter Kf under some conditions in subthreshold.i cannot just plot the OP param,becasue i need to derive it under certain conditions.

Spectre(of Cadence) like BSIM(of Berkley) has developed a method for deriving each parameter in their model.

Is there a way to help me with such manual where i can test in cadence virtuoso the Kf parameter shown in the formula bellow?

Thanks.

Hi,

i'm using spectre HB simulation on PA (Power Amplifier) test_bench to perform large signal analysis (i want to plot Output power vs intput power, PAE and Gain)

Although the simulation returns no error, i still can't plot anything. seem like there is an issue with the ports i'm using. (analoglib ports)

i attach an image of my configuration so maybe you can find something helpful in it. 

thank you all for your help

best regards

hello there, i'm a student studying allegro PCB designer.

There are some commands that i can do with GUI, but i want to know what kind of commands i used so that i can route with commands only(ex) skill).

Is there any file that i can see what kind of commands i used something like log files or command history?

thank you for reading this long boring question.

Hi experts,

I have a problem with my design as below

ERROR: in SHAPE (-2.3622 2.3622)

  class = ETCH

  subclass = TOP 

  Part of Symbol Def SHAPE_4725X4725.

      Which is part of a padstack as a SHAPE symbol.

  ERROR(SPMHDB-187): SHAPE boundary may not cross itself.

   Error cannot be fixed.

       Object has first point location at (-2.3622 2.3622).

Can you tell me how to solve my problem?

Thanks a lot.

Currently I tried this:

axlDBCreateShape(recPolyPlanes t "BOUNDARY/L02" netName sym1)

I get a atom error on car(sym1)

I can do this "static" using ETCH/L02 with out an issue, but I am trying to avoid doing an axlShapeChangeDynamicType().

Thanks,

Jerry

Hi all,

I am creating shapes on plane layers for a coupon and want to void them using axlShapeAutoVoid()

The shapes are attached to a symbol.

I've tried using axlShapeAutoVoid, but this only voids the pins, not the route keepouts created by nc_backdrill.

I also tried selecting the shape, individually, then running axlShapeAutoVoid. That was unsuccessful, also.

planeShapes is a list of shapes I created. The code for voiding:

;run backdrill to get route keepouts
axlShell("setwindow pcb;backdrill setup ;setwindow form.nc_backdrill;FORM nc_backdrill apply ;FORM nc_backdrill close")

foreach(sHape planeShapes
axlShapeAutoVoid(car(sHape))
)

Hi all,

I need to develop a digital design/verification solution to compile,elaborate and simulate SV designs (basically a complex xrun wrapper). I am an experienced user of xrun and I have done a number of these wrappers over the years but this one is to be more of a tool, intented to be used Company-wise, so it needs to be very well thought and engineered.

It needs to be robust, simple and extensible. It needs to support multi-snapshot elaboration, run regressions on machine farms, collect coverage, create reports, etc.

I've been browsing the vast amount of documentation on XCELIUM and, although very good, I can't find any document which puts together all the pieces of what I am trying to achieve. I suppose I am more clear on the elaboration, compilation and simulation part but I am really lacking on the other areas like : LSF, regressions coverage, where does vManager fits in all this, etc.

I'd appreciate if someone can comment on whether there is a document which depicts how such a DV flow can be put together from scratch, or whether there is a kind of RAK with some example xrun wrapper.

Thanks

Specman *search* command allows searching in all loaded modules, but only for a string.

Is there a way to search for a regexp or glob?

Alternatively, is there a way to simply get a list of all loaded files somehow? Then I could use either the "shell" command, or real shell together with grep.

Thanks

I’m not talking about carnival funhouse mirrors, but rather the different options for mirroring symbols, vias, and bond fingers in your IC Package layout. The Allegro Package Designer Plus and SiP Layout tools have two distinct styles of m...(read more)

If you design wire bond packages, you’re familiar with the need for the bond fingers and rings on the package substrate layers to be exposed through the solder mask layer. If they aren’t, it becomes… rather difficult… to bon...(read more)

Those who work in the IC Packaging design space have some unique challenges. We bridge between the IC design world (90/45-degree traces with rectangular and octagonal pins) and the PCB domain (any-angle routing, filled planes, and a multitude of pad ...(read more)

Here are two screen capture of Before and After Autorouting my board. Padstacks have all been revised and corrected. The Capture Schematic is correct. All Footprints have been verified after Padstack revision. a new NETLIST generation have been done after some corrections made in Capture. I have imported the new Logic. I revised my Layout Cross Section as such: TOP, GND, VCC, BOTTOM. Both VCC and GND shapes have been assigned to their respective logical GND and VCC Nets (verified). Yet, I still have the Autorouter to systematically use extra vias to make GND and VCC connections to the VCC and GND planes. Where a simple utilisation of the part padstack inner layer would have been indicated. What Im I missing ?

Hi everybody,

I've created a symbol with custom pad shapes. Everything looks correct in the symbol editor.

And the 3d view looks correct (upside down to show placement)

But when I try to place it on the pcb the 2 "T" shaped pads aren't in the correct location.

I have the pad shape centered on the pad...

with no offset on the padstack editor.

Does anybody know how to fix this?

Thank you!