We’ve all seen bar codes and the more modern QR codes. They’re everywhere you go – items at the grocery store, advertisements and posters, even on websites. Did you know that, with the productivity toolbox in Allegro Package Designe...(read more)
Just in time for the holidays, inside the posted tar ball is some code to solve 9x9 Sudoku puzzles with the Assertion-Driven Simulation (ADS) capability of Incisive Enterprise Verifier (IEV). Enjoy! Joerg Mueller Solutions Engineer for Team Verify
Hello,
I am using Virtuoso 6.1.7.
I am performing the parasitic extraction of a MOM cap array of 32 caps. I use Quantus QRC and I enable field solver. I select “QRCFS” for field solver type and “High” for field solver accuracy. The unit MOM cap is horizontally and vertically symmetric. The array looks like the sketch below and there are no other structures except the unit caps:
Rationally speaking, the capacitance values of the unit caps should be symmetric with respect to a vertical symmetry axis that is between cap16 and cap17 (shown with dashed red line). For example,
the capacitance of cap1 should be equal to the capacitance of cap32
the capacitance of cap2 should be equal to the capacitance of cap31
etc. as there are no other structures around the caps that might create some asymmetry.
Nevertheless, what I observe is the following after the parasitic extraction:
As it can be seen, the result is not symmetric contrary to what is expected. I should also add that I do not observe this when I perform parasitic extraction with no filed solver.
Why do I get this result? Is it an artifact resulting from the field solver tool (my conclusion was yes but still it must be verified)? If not, how can something like this happen?
Many thanks in advance.
Best regards,
Can
Key Findings: Many more design teams will be reaching the mixed-signal methodology tipping point in 2015. That means you need to have a (verification) plan, and measure and execute against it.
As 2014 draws to a close, it is time to look ahead to the coming years and make a plan. While the macro view of the chip design world shows that is has been a mixed-signal world for a long time, it is has been primarily the digital teams that have rapidly evolved design and verification practices over the past decade. Well, I claim that is about to change. 2015 will be a watershed year for many more design teams because of the following factors:
To begin the examination of what is going to change and why, let’s start with what is not changing. IBS reports that mixed signal accounts for over 85% of chip design starts in 2014, and that percentage will rise, and hold steady at 85% in the coming years. It is a mixed-signal world and there is no turning back!
Figure 1. IBS: Mixed-signal design starts as percent of total
The foundational nature of mixed-signal designs in the semiconductor industry is well established. The reason it is exciting is that a stable foundation provides a platform for driving change. (It’s hard to drive on crumbling infrastructure. If you’re from California, you know what I mean, between the potholes on the highways and the earthquakes and everything.)
While the challenges being felt at the advanced nodes, such as double patterning and adoption of FinFET devices, have slowed some from following onto to nodes past 28nm, innovation has just turned in different directions. Applications for Internet of Things, automotive, and medical all have strong mixed-signal elements in their semiconductor content value proposition. What is critical to recognize is that many of the design techniques that were initially driven by advanced-node programs have merit across the spectrum of active semiconductor process technologies. For example, digitally controlled, calibrated, and compensated analog IP, along with power-reducing mutli-supply domains, power shut-off, and state retention are being applied in many programs on “legacy” nodes.
Another graph from IBS shows that the design starts at 45nm and below will continue to grow at a healthy pace. The data also shows that nodes from 65nm and larger will continue to comprise a strong majority of the overall starts.
Figure 2. IBS: Design starts per process node
TSMC made a comprehensive announcement in September related to “wearables” and the Internet of Things. From their press release:
TSMC’s ultra-low power process lineup expands from the existing 0.18-micron extremely low leakage (0.18eLL) and 90-nanometer ultra low leakage (90uLL) nodes, and 16-nanometer FinFET technology, to new offerings of 55-nanometer ultra-low power (55ULP), 40ULP and 28ULP, which support processing speeds of up to 1.2GHz. The wide spectrum of ultra-low power processes from 0.18-micron to 16-nanometer FinFET is ideally suited for a variety of smart and power-efficient applications in the IoT and wearable device markets. Radio frequency and embedded Flash memory capabilities are also available in 0.18um to 40nm ultra-low power technologies, enabling system level integration for smaller form factors as well as facilitating wireless connections among IoT products.
Compared with their previous low-power generations, TSMC’s ultra-low power processes can further reduce operating voltages by 20% to 30% to lower both active power and standby power consumption and enable significant increases in battery life—by 2X to 10X—when much smaller batteries are demanded in IoT/wearable applications.
The focus on power is quite evident and this means that all of the power management and reduction techniques used in advanced node designs will be coming to legacy nodes soon.
Integration and miniaturization are being pursued from the system-level in, as well as from the process side. Techniques for power reduction and system energy efficiency are central to innovations under way. For mixed-signal program teams, this means there is an added dimension of complexity in the verification task. If this dimension is not methodologically addressed, the level of risk adds a new dimension as well.
Risk is the bane of every engineer, but without risk there is no progress. And, sometimes the amount of risk is not something that can be controlled. Figure 3 shows some of the forces at work that cause design teams to undertake more risk than they would ideally like. With price and form factor as primary value elements in many growing markets, integration of analog front-end (AFE) with digital processing is becoming commonplace.
Figure 3. Trends pushing mixed-signal out of equilibrium
The move to the sweet spot of manufacturing at 28nm enables more integration, while providing excellent power and performance parameters with the best cost per transistor. Variation becomes great and harder to control. For analog design, this means more digital assistance for calibration and compensation. For greatest flexibility and resiliency, many will opt for embedding a microcontroller to perform the analog control functions in software. Finally, the first wave of leaders have already crossed the methodology bridge into true mixed-signal design and verification; those who do not follow are destined to fall farther behind.
The factors cited in Reason 3 all have a technical grounding that serves to create pain in the chip-development process. The more factors that are present, the harder it is to ignore the pain and get the treatment relief afforded by adopting known best practices for truly mixed-signal design (versus divide and conquer along analog and digital lines design).
In the past design performance was measured in MHz with simple static timing and power analysis. Design flows were conveniently partitioned, literally and figuratively, along analog and digital boundaries. Today, however, there are gigahertz digital signals that interact at the package and board level in analog-like ways. New, dynamic power analysis methods enabled by advanced library characterization must be melded into new design flows. These flows comprehend the growing amount of feedback between analog and digital functions that are becoming so interlocked as to be inseparable. This interlock necessitates design flows that include metrics-driven and software-driven testbenches, cross fabric analysis, electrically aware design, and database interoperability across analog and digital design environments.
Figure 4. Tipping point indicators
Energy efficiency is a universal driver at this point. Be it cost of ownership in the data center or battery life in a cell phone or wearable device, using less power creates more value in end products. However, layering multiple energy management and optimization techniques on top of complex mixed-signal designs adds yet more complexity demanding adoption of “modern” mixed-signal design practices.
Divide and conquer is always a powerful tool for complexity management. However, as the number of interactions across the divide increase, the sub-optimality of those frontiers becomes more evident. Convergence is the name of the game. Just as analog and digital elements of chips are converging, so will the industry practices associated with dealing with the converged world.
Figure 5. Convergence drivers
Truly mixed-signal design is a discipline that unites the analog and digital domains. That means that there is a common/shared data set (versus forcing a single cockpit or user model on everyone).
In verification the modern saying is “start with the end in mind”. That means creating a formal approach to the plan of what will be test, how it will be tested, and metrics for success of the tests. Organizing the mechanics of testbench development using the Unified Verification Methodology (UVM) has proven benefits. The mixed-signal elements of SoC verification are not exempted from those benefits.
Competition is growing more fierce in the world for semiconductor design teams. Not being equipped with the best-known practices creates a competitive deficit that is hard to overcome with just hard work. As the landscape of IC content drives to a more energy-efficient mixed-signal nature, the mounting risk posed by old methodologies may cause causalities in the coming year. Better to move forward with haste and create a position of strength from which differentiation and excellence in execution can be forged.
2015 is going to be a banner year for mixed-signal design and verification methodologies. Those that have forged ahead are in a position of execution advantage. Those that have not will be scrambling to catch up, but with the benefits of following a path that has been proven by many market leaders.
Key Findings: There are a host of issues that arise in mixed-signal verification. As discussed in earlier blogs, the industry trends indicate that teams need to prepare themselves for a more mixed world. The good news is that these top five pitfalls are all avoidable.
It’s always interesting to study the human condition. Watching the world through the lens of mixed-signal verification brings an interesting microcosm into focus. The top 5 items that I regularly see vexing teams are:
Reason 1: When there’s a bug, whose problem is it?
It actually turns out to be a good thing when a bug is found during the design process. Much, much better than when the silicon arrives back from the foundry of course. Whether by sheer luck, or a structured approach to verification, sometimes a bug gets discovered. The trouble in mixed-signal design occurs when that bug is near the boundary of an analog and a digital domain.
Figure 1. Whose bug is it?
Typically designers are a diligent sort and make sure that their block works as desired. However, when things go wrong during integration, it is usually also project crunch time. So, it has to be the other guy’s bug, right?
A step in the right direction is to have a third party, a mixed-signal verification expert, apply rigorous methods to the mixed-signal verification task. But, that leads to number 2 on my list.
Reason 2: Verification team is the lightning rod
Having a dedicated verification team with mixed-signal expertise is a great start, but what can typically happen is that team is hampered by the lack of availability of a fast executing model of the analog behavior (best practice today being a SystemVerilog real number model – SV_RNM). That model is critical because it enables orders of magnitude more tests to be run against the design in the same timeframe.
Without that model, there will be a testing deficit. So, when the bugs come in, it is easy for everyone to point their finger at the verification team.
Figure 2. It’s the verification team’s fault
Yes, the model creates a new validation task – it’s validation – but the speed-up enabled by the model more than compensates in terms of functional coverage and schedule.
The postscript on this finger-pointing is the institutionalization of SV-RNM. And, of course, the verification team gets its turn.
Figure 3. Verification team’s revenge
Reason 3: Three (conflicting) points of view
The third common issue arises when the finger-pointing settles down. There is still a delineation of responsibility that is often not easy to achieve when designs of a truly mixed-signal nature are being undertaken.
Figure 4. Points of view and roles
Figure 4 outlines some of the delegated responsibility, but notice that everyone is still potentially on the hook to create a model. It is questions of purpose, expertise, bandwidth, and convention that go into the decision about who will “own” each model. It is not uncommon for the modeling task to be a collaborative effort where the expertise on analog behavior comes from the analog team, while the verification team ensures that the model is constructed in such a manner that it will fit seamlessly into the overall chip verification. Less commonly, the digital design team does the modeling simply to enable the verification of their own work.
Reason 4: Wait, there’s more… software
As if verifying the function of a chip was not hard enough, there is a clear trend towards product offerings that include software along with the chip. In the mixed-signal design realm, many times this software has among its functions things like calibration and compensation that provide a flexible way of delivering guards against parameter drift. When the combination of the chip and the software are the product, they need to be verified together. This puts an enormous premium on fast executing SV-RNM.
Figure 5. There’s software analog and digital
While the added dimension of software to the verification task creates new heights of complexity, it also serves as a very strong driver to get everyone aligned and motivated to adopt best known practices for mixed-signal verification. This is an opportunity to show superior ability!
Figure 6. Change in perspective, with the right methodology
Reason 5: There’s a whole new language
Communication is of vital importance in a multi-faceted, multi-team program. Time zones, cultures, and personalities aside, mixed-signal verification needs to be a collaborative effort. Terminology can be a big stumbling block in getting to a common understanding. If we take a look at the key areas where significant improvement can usually be made, we can start to see the breadth of knowledge that is required to “get” the entirety of the picture:
Each of these areas has its own jumble of terminology and acronyms. It never hurts to create a team glossary to start with. Heck, I often get my LDO, IFV, and UDT all mixed up myself.
Summary
Yes, there are a lot of things that make it hard for the humans involved in the process of mixed-signal design and verification, but there is a lot that can be improved once the pain is felt (no pain, no gain is akin to no bugs, no verification methodology change). If we take a look at the key areas from the previous section, we can put a different lens on them and describe the value that they bring:
With all of this value firmly in hand, we can turn our thoughts to happier words:
… stay tuned for more!
Steve Carlson
The complexity and size of mixed-signal designs in wireless, power management, automotive, and other fast growing applications requires continued advancements in a mixed-signal verification methodology. An SoC, in these fast growing applications, incorporates a large number of analog and mixed-signal (AMS) blocks/IPs, some acquired from IP providers, some designed, often concurrently. AMS IP must be verified independently, but this is not sufficient to ensure an SoC will function properly and all scenarios of interaction among many different AMS IP blocks at full chip / SoC level must be verified thoroughly. To reduce an overall verification cycle, AMS IP and SoC verification teams must work in parallel from early stages of the design. Easier said than done! We will outline a methodology than can help.
AMS designers verify their IP meets required specifications by running a testbench they develop for standalone / out of-context verification. Typically, an AMS IP as analog-centric, hierarchal design in schematic, composed of blocks represented by transistor, HDL and behavioral description verified in Virtuoso® Analog Design Environment (ADE) using Spectre AMS Designer simulation. An SoC verification team typically uses UVM SystemVerilog testbech at full chip level where the AMS IP is represented with a simple digital or real number model running Xcelium /DMS simulation from the command line.
Ideally, AMS designers should also verify AMS IP function properly in the context of full-chip integration, but reproducing an often complex UVM SystemVerilog testbench and bringing over top-level design description to an analog-centric environment is not a simple task.
Last year, Cadence partnered with Infineon on a project with a goal to automate the reuse of a top-level testbench in AMS verification. The automation enabled AMS verification engineers to automatically configure setup for verification runs by assembling all necessary options and files from the AMS IP Virtuoso GUI and digital SoC top-level command line configurations. The benefits of this method were:
For more details, please see Infineon’s CDNLlive presentation.
Typically, analog designers verify their AMS IP in schematic driven, interactive environment, while SoC designers use a UVM SystemVerilog testbench ran from a command line. In our last MS blog, we talked about automation for reusing SystemVerilog testbench by analog designers in order to verify AMS IP in exactly same context as in its SoC integration, hence reducing surprises and unnecessary iterations.
But, what about other direction: selecting proper AMS IP views for SoC Verification? Manually export netlist from Virtuoso and then manually assemble together all of the files for use with in command line driven flow? Often, there are multiple views for the same instance (RNM, analog behavioral model, transistor netlist). Which one to pick? Who is supposed to update configuration files? We often work concurrently and update the AMS IP views frequently. Obviously, manually selecting correct and most up-to-date AMS IP views for SoC Verification is tedious and error prone. Thanks to Cadence Innovation, there is a better way!
Cadence has developed a Command-Line IP Selector (CLIPS) product as part of the Virtuoso® environment, which:
For more details, please see CLIPS Rapid Adoption Kit at Cadence Online Support page
Analog and Mixed-signal (AMS) designs are increasingly using active power management to minimize power consumption. Typical mixed-signal design uses several power domains and operate in a dozen or more power modes including multiple functional, standby and test modes. To save power, parts of design not active in a mode are shut down or may operate at reduced supply voltage when high performance is not required. These and other low power techniques are applied on both analog and digital parts of the design. Digital designers capture power intent in standard formats like Common Power Format (CPF), IEEE1801 (aka Unified Power Format or UPF) or Liberty and apply it top-down throughout design, verification and implementation flows. Analog parts are often designed bottom-up in schematic without upfront defined power intent. Verifying that low power intent is implemented correctly in mixed-signal design is very challenging. If not discovered early, errors like wrongly connected power nets, missing level shifters or isolations cells can cause costly rework or even silicon re-spin.
Mixed-signal designers rely on simulation for functional verification. Although still necessary for electrical and performance verification, running simulation on so many power modes is not an effective verification method to discover low power errors. It would be nice to augment simulation with formal low power verification but a specification of power intent for analog/mixed-signal blocs is missing. So how do we obtain it? Can we “extract” it from already built analog circuit? Fortunately, yes we can, and we will describe an automated way to do so!
Virtuoso Power Manager is new tool released in the Virtuoso IC6.1.8 platform which is capable of managing power intent in an Analog/MS design which is captured in Virtuoso Schematic Editor. In setup phase, the user identifies power and ground nets and registers special devices like level shifters and isolation cells. The user has the option to import power intent into IEEE1801 format, applicable for top level or any of the blocks in design. Virtuoso Power Manager uses this information to traverse the schematic and extract complete power intent for the entire design. In the final stage, Virtuoso Power Manager exports the power intent in IEEE1801 format as an input to the formal verification tool (Cadence Conformal-LP) for static verification of power intent.
Cadence and Infineon have been collaborating on the requirements and validation of the Virtuoso Power Manager tool and Low Power verification solution on real designs. A summary of collaboration results were presented at the DVCon conference in Munich, in October of 2018. Please look for the paper in the conference proceedings for more details. Alternately, can view our Cadence webinar on Verifying Low-Power Intent in Mixed-Signal Design Using Formal Method for more information.
Hello everyone, today I’d like to talk to you about the recent enhancements to Die export in the Virtuoso RF Solution, most of which were released in ICADVM 18.1 ISR10. What’s the background for these enhancements? Exporting an abstract of a Die, which basically represents the outer boundary of the Die with I/O locations, as an intermediate file to exchange information between various Cadence tools (i.e., the Innovus, Virtuoso, and Allegro platforms) is not a new feature. This capability existed even prior to the Virtuoso RF Solution. However, the entire functionality was rewritten from scratch when we first started developing the Virtuoso RF Solution because the previous feature was deemed archaic, its performance and capacity needed to be enhanced, and use model needed to be modernized. This effort has been made in various phases, with the last round being completed and released in ICADVM18.1 ISR10.(read more)
બેન્ક ઓફ ઈન્ડીયાએ રિઝર્વ બેન્ક (RBI) દ્વારા નીતિગત વ્યાજદરમાં ઘટાડાનો પૂરો લાભ ગ્રાહકોને આપવાનો નિર્ણય લેવામાં આવ્યો છે.
નાગરીકોને નાણામંત્રીએ ગિફ્ટ આપી છે. સરકારે પ્રાઈવેટ અથવા રાજ્ય સ્વાસ્થ્ય વીમા યોજનાથી લાભાર્થી લોકોને કોરોના વાયરસ સંકટ સમયે રાહત આપવામાં આવી
Amazon, BigBasket, Grofers અને MedLife, લોકડાઉન દરમિયાન જીવના જોખમે ડિલિવરી કરતા બહાદૂુરોને બિરદાવે છે.
BIFનું માનવું છે કે ફેસબુક અને જિયો વચ્ચેની પાર્ટનરશીપ 5 કરોડ માઇક્રો, નાના અને મધ્યમ વેપારોને ફાયદો અપાવશે
Trafscrambler is an anti-sniffer/IDS NKE (Network Kernel Extension) for Mac OS X. This initial release implements SYN-decoy, Pre/Post connections SYN, TCP reset, and zero window attacks. Author tested this on x86 OS X versions 10.5.6 and 10.5.7. It should work on PPC and older releases as well.
Trafscrambler is an anti-sniffer/IDS NKE (Network Kernel Extension) for Mac OS X. Author tested this on x86 OS X versions 10.5.6 and 10.5.7. It should work on PPC and older releases as well.
Trafscrambler is an anti-sniffer/IDS NKE (Network Kernel Extension) for Mac OS X. Author tested this on x86 OS X versions 10.5.6 and 10.5.7. It should work on PPC and older releases as well.
Slackware Security Advisory - New libtiff packages are available for Slackware 14.2 and -current to fix security issues.
VÉLIZY-VILLACOUBLAY, France — October 24, 2019 — Dassault Systèmes (Euronext Paris: #13065, DSY.PA) announces IFRS unaudited financial results for the third quarter and nine months ended September 30, 2019. These results were reviewed by the Group’s Board of Directors on October 23, 2019. This press release also includes financial information on a non-IFRS basis with reconciliations included in the Appendix to this communication. All IFRS and non-IFRS figures are presented in compliance...
VELIZY-VILLACOUBLAY, France — November 13th, 2019 — Dassault Systèmes (Euronext Paris: #13065, DSY.PA) is holding a Life Sciences Day for analysts and investors, today, Wednesday, November 13th, 2019 starting at 09.00 am ET in New York. The event includes presentations by the senior executive management team. The sessions are being webcast live and will be available for replay by accessing https://investor.3ds.com/events/event-details/life-sciences-day. Bernard Charlès, Dassault Systèmes’ Vice...
Dassault Systèmes Reports First Quarter Financial Results With Recurring Software, Operating Margin and EPS At the High End of Its Non-IFRS Guidance
