Microwave Office is Cadence’s tool-of-choice for RF and microwave designers designing everything from III-V 5G chips, to RF systems in board and package technologies. These types of designs require close interaction between the schematic and its layout. A new Training Byte demonstrates how the schematic-layout connections is built into Microwave Office.(read more)

Data sets are a powerful and easy-to-use feature in Microwave Office. Data can be effortlessly be swapped in graphs, and circuit schematics.(read more)

Have you ever wanted to write a DRC rule deck to check for space or width constraints on polygons? Or have you wondered how the multiple lines of an LVS rule deck extract and conduct a comparison between the schematic and layout? Maybe you've been curious about the role of rule deck writers in creating high-quality designs ready for tape-out.

If any of these questions interest you, there is good news: the latest version (v23.1) of the Physical Verification Rules Writer (PVLRW) course is designed to teach you rule deck writing. This free 16-hour online course includes audio and labs designed to make your learning experience comfortable and flexible. Whether you are new to the concept or an experienced CAD/PDK engineer, the course is structured to enhance your rule deck writing skills.

The PVLRW course covers six core modules: Layer Processing, DRC Rules, Layout Extraction, ERC and LVS Rules, Schematic Netlisting, and Coloring Rules. There are also three optional appendix sections. Each module explains relevant rules with syntax, concepts, graphics, examples, and case studies.

This course is based on tool versions PEGASUS231 and Virtuoso Studio IC231.

Pegasus Input and Output

Pegasus is a cloud-ready physical verification signoff solution that enables engineers to support faster delivery of advanced-node integrated circuits (ICs) to market.

Pegasus requires input data in the form of layout geometry, schematic netlists, and rules that direct the tool operation. The rules fall into two categories: those that describe the fabrication process and those that control the job-specific operation.

Pegasus provides log and report files, netlists, databases, and error databases as output.

Overview of Pegasus Rule File

The rule decks written in Physical Verification Language (PVL) work for the Cadence PV signoff tools Pegasus and PVS (Physical Verification System).   

The PVL rules are placed in a file that gets selected in a run from the GUI or the command line, as the user directs. PVL rules may be on separate lines within the file and can also be contained in named rule blocks.

Each line of code starts with a PVL rule that uses prefix type notation. It consists of a keyword followed by options, input layer or variable names, and output layer or variable names.

A rule block has the format of the keyword rule, followed by a rule name you wish to give it, followed by an opening curly brace. You enter the rules you wish to perform, followed by a closing curly brace on the last separate line.

  Sample Rule deck with individual lines of code and rule blocks.

DRC Rules

The first step in a typical Pegasus flow is a Design Rule Check (DRC), which verifies that layout geometries conform to the minimum width, spacing, and other fabrication process rules required by an IC foundry. Each foundry specifies its own process-dependent rules that must be met by the layout design.

There are three types of DRC rules: layer definition rules, layer derivation rules, and DRC design check rules. Layer definition rules identify the layers contained in the input layout database, and layer derivation rules derive additional layers from the original input layers, allowing the tool to test the design against specific foundry requirements using the design check rules.

A sample DRC Rule deck

A layout view displaying the DRC violations

LVS Rules

The Pegasus Layout Versus Schematic (LVS) tool compares the layout netlist with the schematic netlist to check for discrepancies.

There are two essential LVS rule sets: LVS extraction rules and comparison rules. LVS extraction rules help extract drawn devices and connectivity information from the input layout geometry data and outputs into a layout netlist. The LVS extraction rule set also includes the layer definition, derivation, extraction, connectivity, and net listing rules.

LVS comparison rules are associated with comparing the extracted layout netlist to a schematic netlist.

A sample LVS Rule deck. 

TCL, Macros, and Conditional commands

Tcl is supported and used in various Pegasus functionalities, such as Pegasus rule files and Pegasus configurator. Macros are functional templates that are defined once and can be used multiple times in a rule file. Conditional Commands are used to process or skip specific commands in the rule file.

Do You Have Access to the Cadence Support Portal?

If not, follow the steps below to create your account.

• On the Cadence Support portal, select Register Now and provide the requested information on the Registration page.
• You will need an email address and host ID to sign up.
• If you need help with registration, contact support@cadence.com.

To stay up to date with the latest news and information about Cadence training and webinars, subscribe to the Cadence Training emails.

If you have questions about courses, schedules, online, public, or live onsite training, reach out to us at Cadence Training.

For any questions, general feedback, or future blog topic suggestions, please leave a comment.

Related Resources

Product Manuals	Cadence Pegasus Developers Guide
Rapid Adoption Kits	Running Pegasus DRC/LVS/FILL in Batch Mode
Training Byte Videos	What Is the Run Command File? How to Run PVS-Pegasus Jobs in GUI and Batch modes? PVS DRC Run From - Setup Rules What Is PVS/Pegasus Layer Viewer? PVL Coloring Ruledecks with Docolor and Stitchcolor  PLV Commands: dfm_property with Primary & Secondary Layer PVS Quantus QRC Overview
Online Courses	Pegasus Verification System PVS (Physical Verification System) Virtuoso Layout Design Basics

About Knowledge Booster Training Bytes

Knowledge Booster Training Bytes is an online journal that relays information about Cadence Training videos, online courses, and upcoming webinars in the Learning section of the Cadence Learning and Support portal. This blog category brings you direct links to these videos, courses, and other related material on a regular basis. Subscribe to receive email notifications about our latest Custom IC Design blog posts.

Che(read more)

This blog describes how to efficiently use Virtuoso Visualization and Analysis XL.(read more)

This blog helps in demonstrating the use of Pin to trunk routing style which helps in enhancing the layout experience.(read more)

Training Bytes are not just short technical videos; they are particularly designed to provide comprehensive support in understanding and learning various concepts and methodologies.

These comprehensive yet small Training Bytes can be created to show various concepts and processes in a shorter pane of five to ten minutes, for example, running DFT synthesis, scanning insertion, inserting advanced testability features, test point insertion, debugging DFT violations, etc.

In this blog, we will show you the DFT Synthesis Flow with Cadence's Genus Synthesis Solution using small Training Bytes available on the Cadence Learning and Support Portal. To explore these training bytes more, log on to support.cadence.com and select the learning section to choose the training videos, as shown below.

DFT Synthesis Flow with Genus Synthesis Solution

First, we will understand the Synthesis Flow with DFT in the Genus Synthesis Solution:

Understanding a Script File that Used to Run the Synthesis Flow With DFT

Here, we will show you "How to run the Test Synthesis Flow to Insert Scan Chains and Improve the Testability of a Design" in the Genus Synthesis Solution:

Running Test Synthesis Flow to Insert Scan Chains And Improve the Testability of a Design in the Genus Synthesis Solution

Let's check the flops marked with the dft_mapped attribute for scan mapping in Genus Synthesis Solution:

How to Check Flops Marked With dft_mapped Attribute For Scan Mapping in Genus Synthesis Solution?

How to Find Non-Scan Flops of a Design in Genus? (Video)

Once the flops are mapped to scan flip flops and the scan chain inserted, we will see how to handle the flops marked with the dft_dont_scan attribute for scan mapping in Genus Synthesis Solution.

How to Handle the Flops Marked With the dft_dont_scan Attribute For Scan Mapping in Genus Synthesis Solution?

Here, we will see how to fix DFT Violations using the command fix_dft_violations:

Fixing DFT Violations (Video)

Once the design has been synthesized, let's explore the DFT design hierarchy in Genus Stylus CUI:

Exploring DFT Design Hierarchy in Genus Stylus CUI (Video)

Understand why sequential elements are not mapped to a scan flop:

Why Are Sequential Elements Not Mapped to a Scan Flop?

Explore hierarchical scan synthesis in Genus Stylus Common UI:

Understanding Hierarchical Scan Synthesis in Genus Stylus Common UI. (Video)

To understand how to resolve different warnings and errors (for example, DFT-415, DFT-512, DFT-304, etc.) in Genus Synthesis Solution, here are some videos you can refer to:

How to Resolve Warning: DFT-415 (Video)

How to Resolve Error: DFT-407 (Video)

How to Resolve Error: DFT-404 (Video)

DFT-510 Warning During Mapping (Video)

How to Resolve Warning: DFT-512 (Video)

How to Resolve Warning: DFT-511 (Video)

How to Resolve Warning: DFT-304 (Video)

How to Resolve Warning: DFT-302 (Video)

How to Resolve Error: DFT-515 (Video)

How to Resolve Error: DFT-500 (Video)

Here, we will see how we can generate SDC constraints for DFT constructs for many scan insertion techniques, such as FULLSCAN, OPCG, Boundary Scan, PMBIST, XOR Compression, SmartScan Compression, LBIST, and IEEE 1500:

How to Generate SDC Constraints for DFT Constructs in Genus Synthesis Solution? (Video)

Explore advanced testability features that can be inserted in Genus Synthesis Solution, such as Boundary Scan, Programmable Memory built-in Self-Test Logic (PMBIST), Compression Logic, Masking, and On-Product Clock Generation Logic (OPCG):

Advanced Testability Features (Video)

To understand What the IEEE 1500 Wrapper and its Insertion Flow in Genus Synthesis Solution, follow the bytes:

What Is IEEE 1500 Wrapper? (Video)

IEEE 1500 Wrapper Insertion Flow in Genus Synthesis Solution (Video)

Understand the On-product Clock Generation (OPCG) insertion flow in Genus Synthesis Solution Stylus CUI with this byte:

Understanding On Product Clock Generator (OPCG) Insertion in Genus Stylus CUI (Video)

To debug DFT violations, you can use DFT Analyzer from Genus GUI and explore its features here:

Debugging Using GUI: DFT Analyzer (Video)

Exploring DFT Analyzer View of Genus Synthesis Solution GUI (Video)

To understand What is Shadow Logic, How to Insert Test Points, How to do Testability Analysis Using LBIST, and How to Deterministic Fault Analysis in Genus, follow this article:

What is Shadow Logic

To insert the Boundary Scan Logic in and control Boundary Optimization in Genus Synthesis Solution, refer to these small bytes:

How to Insert Boundary Scan Logic in Genus? Video)

Controlling Boundary Optimization in Genus Synthesis Solution Stylus CUI (Video)

Compression techniques are used during scan insertion to reduce the test data volume and test application time (TAT) while retaining the test coverage. To understand what compression and the compression techniques are, watch this article:

What is Compression Technique During Scan Insertion? (Video)

Interested to know what "Unified Compression" is? To get the concept, you can watch this small demo:

What Is Unified Compression? (Video)

To Explore More, Register for Online Training

• Log on to Cadence.com with your registered Cadence ID and password.
• Select Learning from the menu > Online Courses.
• Search for "Test Synthesis with Genus Stylus Common UI" using the search bar.
• Select the course and click "Enroll."