Functional coverage has been the most widely accepted way by which we track the completeness of any constrained random testbench. However, does achieving 100% functional coverage means that the DUV is bug free? Certainly not , but it boosts the confidence of the verification engineer and management team.

Based on my experience of defining functional cover groups for different projects, I realized that coverage constructs and options in the SystemVerilog language have their own nuances for which one needs to keep an eye out. These “gotchas” have to be understood so that coverage can be used optimally to achieve appropriate usage results in correct alignment with the intent desired. Let me talk about some of these finer aspects of coverage so that you can use the constructs more productively.