Cadence® system design and verification solutions, integrated under our Verification 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.
More Support Log In
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 technology. 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
The purpose for creating a Pcell is to automate the creation of data. Pcells should be designed as standalone entities, independent of the environment in which they are created and independent of the variety of environments in which you or someone else might want to use them. An environment can react to a Pcell, but Pcell code should not react to, interact with, or be dependent on an environment. Although it is possible to create Pcells dependent on something in your current or local environment, and/or using unsupported or un-recommended functions, Pcell code is likely to fail when you try to translate it for a different environment.
Functions that are not supported for use within SKILL pcells usually belong to specific applications (tools); they are unknown to other environments, to other tools, and to data translators. For example, if you create a Pcell in the Virtuoso environment and include place-and-route functions, the Pcell will fail in the layout environment. Also, application-specific functions that are not supported for customer use can disappear or change, without notice.
Why you should create a Pcell? Creating Pcells for the ECO sometimes helps when we are not sure what size of cell we will have to use for fixing timing violations. Then, just changing a parameter in the Pcell may do the trick. Generally, you can identify them by their prefixes. However, you can also use all of the basic SKILL language functions. In the following example, we will demonstrate how you can insert the buffer during hold time fix (as part of the ECO) flow using Pcell:
1. At the Linux prompt set the following environment variables:
setenv CDS_ENABLE_EXP_PCELL true
setenv CDS_EXP_PCELL_DIR ./.expressPcells
2. Invoke Virtuoso and open the design. Note that for Virtuoso versions before IC22.214.171.1240.1, VLS-XL or VLS-GXL is required to save the express PCell cache. In IC126.96.36.1990.1 and later versions, all Virtuoso products support this.
3. Select Tools->Express Pcell Manager. Fill out all the details and Enable Caching of the Pcells check box with Auto Save option. Press Save Copy to save the Pcell Layout Cache. This step is necessary to enable inter-operation of the data between Encounter and Virtuoso.
4. Open the design using
Library Manager -> <Library name> <Cell name> <view name>
5. Zoom and select the flip-flop (FF1), in front of which the Pcell has to be inserted.
6. To placed the Pcell go to create -> Instance -> Library:pcell cell:pcell view:layout and placed the instance (I1) to a specific location (x1, y1) in between the flip-flop (FF1) and previous Instance (I2).
7. To do the connectivity
Select I2 instance->connectivity->net->propagate-> A: I2 Y: net1
Select I1 instance->connectivity->net->propagate-> A: net1 Y: net2
Select FF1 Instance->connectivity->net->propagate->D: net2
8. Press Save copy to save the design to OA and exit Virtuoso.
9. To do ECO routing in the Encounter Digital Implementation System (EDIS), make sure the same environment variables of step 1 is set before invoking the tool.
10. Before restoring the OA design database, update the config file with the Pcell library as below:
set rda_Input(ui_timelib,max) ./lib/max/spcbuf_wc.lib"
set rda_Input(ui_timelib,min) ./lib/min/spcbuf_bc.lib"
11. Within EDI, follow these steps to restore the OA design.
restoreOaDesign <Library name> <cell name> <view name>
The design, including the Pcells, should now be read in properly. If the Pcells still do not appear correctly, remove the ./.expressPcells directory and repeat steps 1-4 above. This will make sure new Pcell abstracts are created.
Note: In IC6.1.4 onwards, the cache saved is in a different format than what is saved by IC6.1.3. IC614 can read the Express PCell Cache created by IC6.1.3 and IC6.1.4, but IC6.1.3 cannot read the Express PCell Cache created by IC6.1.4. If you have made a cache using IC6.1.4 then make sure the LD_LIBRARY_PATH environment variable points to <IC6.1.4>/tools/lib while using EDIS. For example:
setenv LD_LIBRARY_PATH <IC6.1.4>/tools/lib
If the cache was made by IC6.1.3 then the LD_LIBRARY_PATH variable can be set to the tools/lib directory under your IC6.1.3 installation.
12. Finally, take the following steps to do the hold time fixing and save the design into OA database:
timeDesign -postRoute -hold
saveOaDesign <Library name> <cell name> <view name1>