A new OVM Layering Package that provides a means to add layers of tests (sequences) without modifying the underlying testbench and without extending components or using the factory to override implementation is available for download.
The DVCon 2010 paper on this topic, You Are In a Maze of Twisty Little Sequences, All Alike – or Layering Sequences for Stimulus Abstraction, is also part of the download kit. The paper demonstrates building layered stimulus using OVM sequences and sequencers. Virtual sequences and virtual sequencers are highlighted by building a small collection of examples that can be used in layered stimulus verification environments. The main contribution of this paper is a new layering component that performs the standard layering task while minimizing user programming without requiring exotic connectivity, extended components or the use of the factory.
Using layered sequences can make your verification life easier, since sequences and sequencers are natively parallel and have arbitration and other communication process hooks already built-in. To learn more, download the kit. You will also find a presentation in the kit and how to use it with the OVM 2.0 Register Package mentioned in my last blog.