TrekUVM « Breker Verification Systems

April 19th, 2017
Booth # 2
Parkyard Hotel, Shanghai

April 26, 2017
San Jose, CA

TrekUVM automatically generates self-verifying test cases that run in existing transactional testbenches, including those compliant with the Universal Verification Methodology (UVM) standard. This verifies your chips more quickly and more thoroughly than using UVM alone to generate transactions. TrekUVM’s generated test cases target all aspects of full-chip verification and work in a variety of different environments.


TrekUVM Flow

TrekUVM supports a natural thought process about chip verification, helping you “mind map” how the design should work and what the verification flow should be. It helps you create scenario models that define your verification space in a textual or an intuitive graphical form, allowing you to deliver a modular, extensible and scalable solution for the functional verification of large, complex chips.

From your scenario models, TrekUVM generates test cases using UVM transactions and connects to the input and outputs of your chip via your existing UVM verification components (UVCs) without requiring a complete testbench. Specifically, you do not need to provide a virtual sequencer, a scoreboard, or a chip-level coverage model. The test cases generated by TrekUVM include input stimulus, results checking, and coverage. This provides completely automated controllability and monitoring of your design.

TrekUVM Flow

TrekUVM in a Typical Verification Flow

Note that TrekUVM works in precisely the same way for IP blocks, clusters of IP blocks, or complete chips. In all cases the existing UVM testbench and UVCs are leveraged to connect to the design. Lower-level graphs can be composed together to form scenario models at the next level in the design hierarchy. This level of verification reuse is not possible with other testbench elements such as virtual sequencers.

The benefits of TrekUVM include:

  • Modular, extensible and scalable solution for UVM verification
  • Flexible, incremental deployment with high return on investment (ROI)
  • Visualization and coverage analysis of verification scenarios
  • Reusable verification modules

TrekUVM Scenario Models

TrekUVM takes as input a hierarchy of graph-based scenario models. Scenario models are developed in C using a simple paradigm of graphs and graph constraints. There are only a small number of constructs to learn. Scenario models “begin with the end in mind” by starting with the possible outcomes. The TrekUVM test case generator walks the graph, randomizing both selection points and data values as it generates the test cases for the chip.

At test generation time, as opposed to test run time, TrekUVM makes constrained-random decisions about services in order to stress chip interactions. This strategy yields individual test cases that are efficient, repeatable and simple to debug while allowing sophisticated decisions to be made for each decision point in the graph.

TrekUVM Visual Coverage


Visualizing Scenario Models

The modular graph-based structure of scenario models makes it possible to visualize the possible paths and the constraints applied to those paths. TrekUVM provides reachability analysis on the scenario model that highlights unreachable test cases. These visualization capabilities make it convenient to review the chip verification model for completeness.

TrekUVM tracks the paths through the model that have been exercised. The achieved coverage can be visualized as a hot-spot graph and analyzed to ensure that cross-coverage cases of interest have been exercised. This scenario-level coverage is complementary to traditional coverage metrics.

The modular organization of scenario models enables reuse from the IP component to the full-chip level and across projects, derivatives and new platforms. For example, an IP driver scenario model contains no system-specific information and can be used with any UVM that incorporates the IP component.

TrekUVM Test Case Visualization

TrekUVM provides industry-leading visualization of the multi-threaded test cases that it generates. The scenario models show where parallelism is possible in the design, and TrekUVM will exploit this in order to stress the chip as much as possible. In this example, there might be multiple concurrent transactions active within the crossbar as well as multiple transactions executing serially in the queue.

This unique visualization display is generated by TrekBox, the module of TrekUVM that runs in simulation to coordinate activity between the UVC testbench components on the UVM’s I/O ports and the overall the test case. TrekBox updates this display in real time as the simulation progresses.