November 26, 2007 -- Functional verification is an art, or so we are told. New technologies emerge that inject a dose of science into the process and these can make the process more predictable, increase efficiency and lower overall verification costs. This article exposes problems with current coverage metrics being used and looks at some recent advances that can make them more objective.

There are two primary roles for coverage metrics: 1) to provide an indication of the degree of completeness of the verification task and 2) to help identify the weaknesses in the verification strategy. The measure of completeness, while often based on objective measures, has traditionally been treated as subjective since most of the metrics in use today can only identify when the task is not complete, rather than when it is complete. This article will explore the reasons for this and how those metrics can be improved.

To look for solutions to these issues, it is worth exploring some basics of verification.

By Brian Bailey. (Brian Bailey is an independent functional verification and electronic system level consultant and the owner of Bran Bailey Consulting.)