Cadence® system design and verification solutions, integrated under our System Development Suite, provide the simulation, acceleration, emulation, and management capabilities.
System Development 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
As more and more custom/analog designs migrate to advanced process nodes (<65nm), design teams are being confronted with an ever-increasing need to better manage the impact of parasitics throughout the entire custom/analog design flow. In addition, more and more layout design teams are finding themselves drawn into the front-end design team's simulation flow and their path to parasitic closure.
But why is a new approach needed, when many custom/analog methodologies today already incorporate estimated layout dependent effects in PCell device models, device callbacks, and in estimated wire models? At advanced process nodes, layout-dependent effects increasingly not only have to take into account separate device and wire effects, but also the effects of devices and wires related to their surrounding environments,. Anywhere from 20-30% of a circuit's performance can be attributed to the effects of the surrounding environment.
Two such layout dependent effects are shallow trench isolation (STI) and well proximity effect (WPE). STI effects for a device must take into account the distance of a gate to each edge of the diffusion, gate to gate separation, and the overall length of the diffusion. As such, any handcrafting of devices or groups of devices -- including any folding, merging, abutting, and dummy insertion -- all impact STI effects and a consequently a device's performance.
Figure 1 -- STI Illustration
WPE effects must take into account the distance or proximity of a device to the edge of the well, and in turn a device's performance is directly correlated to this distance. This effect can only be accurately determined after placement and any handcrafting, including any merging of multiple devices into common wells.
Continuing with inaccurate parasitic estimation methodologies or inserting time-consuming handcrafted layouts in the midst of highly iterative front-end simulation flows would not only have a negative impact on the productivity of both the front-end design team and layout team, but would increase overall risk in the success of a product.
Thus, new custom/analog design flow methodologies that provide more accurate parasitic estimates faster and sooner in the design flow are needed for advanced node designs.
The Virtuoso parasitic-aware design flow provides parasitic closure faster and in fewer design iterations, without sacrificing design performance on advanced node designs. The Virtuoso parasitic-aware design flow spans the design, verification and implementation phases of custom/analog design. For an overview of the entire Virtuoso parasitic-aware design flow, please see Richard Goering's blog, and for details on the design and verification phases, please see Rama Jupalli's blog. The remainder of this blog will focus on the physical implementation or layout phase, and specifically how Rapid Analog Prototyping delivers more accurate parasitic estimates faster.
Better Productivity for Managing Parasitics
Rapid Analog Prototyping brings handcrafted layout a needed boost in productivity required for managing parasitics in advanced node designs. It does this by selectively automating key aspects of custom/analog layout, providing direct access to advanced automated technologies from the familiar industry-standard Virtuoso layout cockpit, all integrated on a common Open Access database.
By allowing layout designers to selectively automate key aspects of custom/analog layout, they can rapidly create layout prototypes with more accurate parasitics for front-end designers, while focusing their creativity on precision hand crafting final layouts.
There are three key Rapid Analog Prototyping tasks in the physical implementation or layout phase of the Virtuoso parasitic-aware design flow:
Virtuoso's advanced module generators are built on SKILL PCells to automatically assist a layout designer in generating complex, highly matched, structured arrays of devices for common analog subcircuits like differential pairs, current mirrors, and more. A layout designer can selectively automate merging, abutting, and interdigitating multiple devices, as well as inserting dummies and guardrings. The module generators rapidly create DRC and LVS correct layout ready for parasitic extraction while accurately reflecting layout dependent effects such as STI effects.
Virtuoso's advanced custom/analog device placement is capable of rapid constraint driven placement of SKILL PCells and module generators. A layout designer can selectively create rapid placement prototypes in three increasing modes of automation: quick placement for quick area estimation, quick placement based on device positioning in the schematic, and fully automated placement that minimizes area and overall wire length and automatically places similar devices in clusters and merges common wells. The rapid analog placements are DRC and LVS correct layouts ready for parasitic extraction, while accurately reflecting layout dependent effects such as WPE effects.
Virtuoso's advanced custom/analog net routing is provided by the Space-Based Router technology. A layout designer can selectively complete net routing in increasing modes of automation - interactive wire editing, assisted autorouting and fully automated routing. All net routing is DRC and LVS correct layout ready for parasitic extraction, while more accurately reflecting layout dependent effects of wires.
Rapid Analog Prototyping and the Virtuoso parasitic-aware design flow are part of a recently announced Cadence Silicon Realization custom/analog flow focused on unified intent, abstraction, and convergence. This flow leverages the breadth, depth, and integration of Virtuoso Schematic Editor, Virtuoso Analog Design Environment, Virtuoso MMSIM, Virtuoso Layout Suite, and in-design manufacturing Virtuoso DFM.
Please send me your comments on what issues you see with parasitics, how you manage those today in your design flows, and what improvements you would like to see.
Loking forward to see a full demo at DAC in San Diego. After that I can write my comments...