The purpose of the verification plan, or vplan as we call it, is to capture all the verification goals needed to prove that the device works as specified. It’s a big responsibility! Getting it right means having a good blueprint for verification closure. However, getting it wrong could result in bug escapes, wasting of resources, and possibly leading to a device failing altogether. In fact, verification planning is so important that the Verisium Manager (formerly vManager)'s Total Verification Management philosophy begins and ends with the vPlan. Verisium Manager’s Planning Center and vPlan Analysis Center provide all necessary capabilities and automation. With the focus on AI-driven verification, the efficiency and effectiveness of verification planning are expected to improve significantly.
There are several key elements needed to create a good vPlan. We will go over a few below.
Accurate Verification Features Are Needed for Verification Closure
The concept of Divide and Conquer suggests that every complex feature can be broken down into sub-features, which in turn can be further divided. The Planning Center facilitates this process by enabling users to create expandable/collapsible feature sections, a crucial capability for maintaining quality. Not having this key capability can put quality at risk.
Close Alignment to the Functional Specification
Close adherence to the functional specification is crucially linked to the first point. Any new features or changes to existing ones should prompt immediate updates to the vPlan, as failing to do so could affect verification quality. The Planning Center allows users to associate paragraphs in the specification to the vPlan and provides notifications of any corresponding alterations. This allows users to respond by adjusting the vPlan accordingly in alignment with the specifications.
Connecting Relevant Metrics, vPlan Features
Once the vPlan is defined, it’s important to connect the relevant metrics to demonstrate verification assurance of each feature. It may involve using a combination of code coverage, functional coverage, or directed test to provide that assurance. The Planning Center makes connecting these metrics to the vPlan very straightforward. Failing to link these metrics with the features could result in insufficiently verified features.
Showing Real-Time Results
To effectively monitor progress and respond promptly to areas requiring attention, the vPlan should dynamically reflect the results in real time. This allows for accurate measurement of progress and focused allocation of resources. Delayed results could lead to wasted project time in non-priority areas. Verisium Manager’s vPlan Analysis automates this process enabling users to view real-time vplan status for relevant regressions.
Customers have shared that vPlan quality significantly influences project outcomes. It's crucial to prioritize creating higher quality vPlans, rather than simply focusing on speed. However, maintaining consistent high quality can be challenging due to the human tendency to quickly lose interest, with initial strong efforts tapering off as the process continues.
A thorough verification plan is the key to success in ASIC verification. Verification reuse is critical to the productivity and efficiency of system-on-chip (SoC), and a good vPlan is the first step in this direction. If you’re a verification engineer, take the time to develop a thorough verification plan for your next project. It will be one of the best investments you can make in the success of your project.