JasperGold Coverage Unreachability App

Automating the previously tedious, time-consuming code coverage analysis process, the Cadence^® JasperGold^® Coverage Unreachability (UNR) App saves weeks of time to attain verification closure. The app takes partially complete simulation coverage database and register-transfer level (RTL) code for the design-under-test (DUT) as inputs, and automatically generates properties to formally explore the reachability of uncovered cover points remaining in the database. The app can be readily used by simulation users with minimal formal verification experience.

When verification teams measure simulation coverage attained versus effort spent to create further simulation tests, the typical curve is initially steep and greatly flattens later on, signifying diminishing returns of adding new tests. A much greater effort is needed to create tests that increase “last mile” coverage significantly. The knee of this curve may occur anywhere in the 70-95% code coverage range, depending on the DUT. This is an optimal point to run the Coverage Unreachability App. 

Using the app, you can create properties to explore the reachability of the remaining points, identifying points that can be eliminated from further consideration and focusing on where further test creation efforts can be useful. Through this process of formal-assisted coverage closure, the app can save weeks of effort. 

Key Features

• Automatically generates properties to explore the reachability of yet-to-be-hit cover points in the simulation coverage database
• Outputs a database of unreachable points for easy review, to highlight DUT or testbench bugs
• Supports automatic merging of the set of reviewed and accepted unreachables with the simulation coverage database to improve coverage closure metrics
• Supports Cadence Xcelium^™ Parallel Simulator, Unicov database, and the Integrated Metrics Center