Verification Academy

Search form

My Account Menu

  • Register
  • Log In
  • Topics
  • Courses
  • Forums
  • Patterns Library
  • Cookbooks
  • Events
  • More
  • All Topics
    The Verification Academy offers users multiple entry points to find the information they need. One of these entry points is through Topic collections. These topics are industry standards that all design and verification engineers should recognize. While we continue to add new topics, users are encourage to further refine collection information to meet their specific interests.
    • Languages & Standards

      • Portable Test and Stimulus
      • Functional Safety
      • Design & Verification Languages
    • Methodologies

      • UVM - Universal Verification Methodology
      • UVM Framework
      • UVM Connect
      • FPGA Verification
      • Coverage
    • Techniques & Tools

      • Verification IP
      • Simulation-Based Techniques
      • Planning, Measurement, and Analysis
      • Formal-Based Techniques
      • Debug
      • Clock-Domain Crossing
      • Acceleration
  • All Courses
    The Verification Academy is organized into a collection of free online courses, focusing on various key aspects of advanced functional verification. Each course consists of multiple sessions—allowing the participant to pick and choose specific topics of interest, as well as revisit any specific topics for future reference. After completing a specific course, the participant should be armed with enough knowledge to then understand the necessary steps required for maturing their own organization’s skills and infrastructure on the specific topic of interest. The Verification Academy will provide you with a unique opportunity to develop an understanding of how to mature your organization’s processes so that you can then reap the benefits that advanced functional verification offers.
    • Universal Verification Methodology (UVM)

      • Advanced UVM
      • Basic UVM
      • Introduction to UVM
      • UVM Connect
      • UVM Debug
      • UVMF - One Bite at a Time
    • Featured Courses

      • Introduction to ISO 26262
      • Introduction to DO-254
      • Clock-Domain Crossing Verification
      • Portable Stimulus Basics
      • Power Aware CDC Verification
      • Power Aware Verification
      • SystemVerilog OOP for UVM Verification
    • Additional Courses

      • Assertion-Based Verification
      • An Introduction to Unit Testing with SVUnit
      • Evolving FPGA Verification Capabilities
      • Metrics in SoC Verification
      • SystemVerilog Testbench Acceleration
      • Testbench Co-Emulation: SystemC & TLM-2.0
      • Verification Planning and Management
      • VHDL-2008 Why It Matters
    • Formal-Based Techniques

      • Formal Assertion-Based Verification
      • Formal-Based Technology: Automatic Formal Solutions
      • Formal Coverage
      • Getting Started with Formal-Based Technology
      • Handling Inconclusive Assertions in Formal Verification
      • Sequential Logic Equivalence Checking
    • Analog/Mixed Signal

      • AMS Design Configuration Schemes
      • Improve AMS Verification Performance
      • Improve AMS Verification Quality
  • All Forum Topics
    The Verification Community is eager to answer your UVM, SystemVerilog and Coverage related questions. We encourage you to take an active role in the Forums by answering and commenting to any questions that you are able to.
    • UVM Forum

      • Active Questions
      • Solutions
      • Replies
      • No Replies
      • Search
      • UVM Forum
    • SystemVerilog Forum

      • Active Questions
      • Solutions
      • Replies
      • No Replies
      • Search
      • SystemVerilog Forum
    • Coverage Forum

      • Active Questions
      • Solutions
      • Replies
      • No Replies
      • Search
      • Coverage Forum
    • Additional Forums

      • Announcements
      • Downloads
      • OVM Forum
  • Patterns Library
    The Verification Academy Patterns Library contains a collection of solutions to many of today's verification problems. The patterns contained in the library span across the entire domain of verification (i.e., from specification to methodology to implementation—and across multiple verification engines such as formal, simulation, and emulation).
    • Implementation Patterns

      • Environment Patterns
      • Stimulus Patterns
      • Analysis Patterns
      • All Implementation Patterns
    • Specification Patterns

      • Occurrence Property Patterns
      • Order Property Patterns
      • All Specification Patterns
    • Pattern Resources

      • Start Here - Patterns Library Overview
      • Whitepaper - Taking Reuse to the Next Level
      • Verification Horizons - The Verification Academy Patterns Library
      • Contribute a Pattern to the Library
  • All Cookbooks
    Find all the methodology you need in this comprehensive and vast collection. The UVM and Coverage Cookbooks contain dozens of informative, executable articles covering all aspects of UVM and Coverage.
    • UVM Cookbook

      • UVM Basics
      • Testbench Architecture
      • DUT-Testbench Connections
      • Configuring a Test Environment
      • Analysis Components & Techniques
      • End Of Test Mechanisms
      • Sequences
      • The UVM Messaging System
      • Other Stimulus Techniques
      • Register Abstraction Layer
      • Testbench Acceleration through Co-Emulation
      • Debug of SV and UVM
      • UVM Connect - SV-SystemC interoperability
      • UVM Versions and Compatibility
      • UVM Cookbook
    • Coding Guidelines & Deployment

      • Code Examples
      • UVM Verification Component
      • Package/Organization
      • Questa/Compiling UVM
      • SystemVerilog Guidelines
      • SystemVerilog Performance Guidelines
      • UVM Guidelines
      • UVM Performance Guidelines
    • Coverage Cookbook

      • Introduction
      • What is Coverage?
      • Kinds of Coverage
      • Specification to Testplan
      • Testplan to Functional Coverage
      • Bus Protocol Coverage
      • Block Level Coverage
      • Datapath Coverage
      • SoC Coverage Example
      • Requirements Writing Guidelines
      • Coverage Cookbook
  • All Events
    No one argues that the challenges of verification are growing exponentially. What is needed to meet these challenges are tools, methodologies and processes that can help you transform your verification environment. These recorded seminars from Verification Academy trainers and users provide examples for adoption of new technologies and how to evolve your verification process.
    • Upcoming & Featured Events

      • Low Power Verification - 4/29
      • Fault Campaign for Mixed-Signal - 5/4
      • User2User - 5/26
      • Webinar Calendar
    • On-Demand Webinars

      • CDC+RDC Analysis
      • Basic Abstraction Techniques
      • Safety Analysis Techniques
      • QVIP Workflow and Debug for PCIe
      • Writing a Proxy-driven Testbench
      • Achieving High Defect Coverage
      • Visualizer Features
      • All On-Demand Webinars
    • Recording Archive

      • Siemens EDA 2021 Functional Verification Webinar Series
      • Improving Your SystemVerilog & UVM Skills
      • Should I Kill My Formal Run?
      • Visualizer Debug Environment
      • Industry Data & Surveys
      • All Recordings
    • Conferences

      • DVCon 2021
      • DVCon 2020
      • DAC 2019
      • All Conferences
    • Mentor Learning Center

      • SystemVerilog Fundamentals
      • SystemVerilog UVM
      • View all Learning Paths
  • About Verification Academy
    The Verification Academy will provide you with a unique opportunity to develop an understanding of how to mature your organization's processes so that you can then reap the benefits that advanced functional verification offers.
    • Blog & News

      • Verification Horizons Blog
      • Academy News
      • Academy Newsletter
      • Technical Resources
    • Verification Horizons Publication

      • Verification Horizons - March 2021
      • Verification Horizons - November 2020
      • Verification Horizons - July 2020
      • Issue Archive
    • About Us

      • Verification Academy Overview
      • Subject Matter Experts
      • Contact Us
    • Training

      • Questa Basic
      • Questa Advanced
      • Mastering Questa
  • Home
  • Technical Resources
  • Supercharge Your Verification Using Rapid Expression Coverage as the Basis of a MC/DC-Compliant Coverage Methodology

Supercharge Your Verification Using Rapid Expression Coverage as the Basis of a MC/DC-Compliant Coverage Methodology

Authors:

  • Gaurav Kumar Verma - Mentor Graphics
  • Doug Warmke - Mentor Graphics

Abstract:

Technology advances allows for the creation of larger and more complex designs. This poses new challenges, including efforts to balance verification completeness with minimization of overall verification effort and cycle time. It is practically impossible to enumerate all of the conditions and states to do an exhaustive test. Therefore, it is imperative to use well defined criteria to measure and check when the verification is sufficiently complete and meets a reasonable quality threshold. Code coverage is a popular measure of design quality. This paper focuses on expression coverage, which is one of the most complex and least understood types of code coverage, and discusses 'Rapid Expression Coverage' (REC), which is a new metric for expression coverage, while comparing it with some popular metrics being used to evaluate expression coverage in the industry today. Even though this paper describes REC in context of code coverage of designs, these same techniques could also be applied to coverage tools for software languages like C, C++, or Java.

Introduction:

Code coverage is a popular measure of design quality and verification completeness. It has low setup cost and analysis is straightforward, which makes it a high ROI component of most modern verification methodologies. Expression coverage is one of the most complex and least understood types of code coverage. The main question verification engineers need to answer regarding expression coverage is:

"There are 2N possible input vectors for my N-input expression. I saw a subset of this large number during simulation. How well is my expression tested?"

A variety of metrics are available to help answer this question. Metrics distill the data to a meaningful numeric value that can be analyzed and improved. There are brute force metrics like the sum-of-products and truth table analysis. These require a large number of test vectors for the expression to be covered. Then there are smarter metrics like Focused Expression Coverage, which is a form of Modified Condition/Decision Coverage (MC/DC). These metrics allow an expression to be fully covered with just 2xN input vectors. Most expression coverage metrics are based on truth table implementations, and therefore suffer from capacity limitations due to exponential complexity.

REC is based on partitioning an expression into sub-expressions to derive non-masking conditions, while operating at linear complexity and providing MC/DC-compliant results. This allows any arbitrarily large expression to be considered for coverage, while providing simple and easy to understand reports.

The basis of REC is that an expression input must not be masked by the values of other inputs at the time of coverage collection. For example, 'b' must be '1' while measuring the coverage of 'a' in 'a && b'. If 'b' is 0, the result of the expression gets fixed to '0' and the value of 'a' is not of any significance. The '1' state of 'b' is called its non-masking state, and the associated condition is called the non-masking condition.

As REC collects coverage, it ensures that the input being covered has taken both '0' and '1' states while an appropriate non-masking condition is satisfied. An expression is considered covered when all its inputs have been independently covered.

The following sections go into the details of partitioning an expression to derive non-masking conditions, the effect of short-circuiting, considerations for duplicate input terminals, inverting vs. non-inverting input modes, and uni-modal versus bi-modal expression considerations.

The results of performance benchmarks show REC has higher performance with similar level of comprehensiveness in expression coverage as compared to existing implementations. These results are presented towards the end of the paper.

View & Download:

Read the entire Supercharge Your Verification Using Rapid Expression Coverage as the Basis of a MC/DC-Compliant Coverage Methodology technical paper.

Source:

DVCon 2014

  Supercharge Your Verification Using Rapid Expression Coverage as the Basis of a MC/DC-Compliant Coverage Methodology
Siemens Digital Industries Software

Siemens Digital Industries Software

##TodayMeetsTomorrow

Solutions

  • Cloud
  • Mendix
  • Siemens EDA
  • MindSphere
  • Siemens PLM
  • View all portfolio

Explore

  • Digital Journeys
  • Community
  • Blog
  • Online Store

Siemens

  • About Us
  • Careers
  • Events
  • News and Press
  • Newsletter
  • Customer Stories

Contact Us

USA:

phone-office +1 800 547 3000

See our Worldwide Directory

  • Contact Us
  • Support Center
  • Give us Feedback
©2021 Siemens Digital Industries Software. All Rights Reserved.
Terms of Use Privacy Cookie Policy