VLSI DV Interview Puzzles · All levels
Scenario: Coverage Not Closing
Functional coverage plateaus after many regression cycles even though new seeds are added daily. Team suspects remaining bins are either unreachable, mis-modeled, or blocked by testbench sequencing gaps.
Scenario
Functional coverage plateaus after many regression cycles even though new seeds are added daily. Team suspects remaining bins are either unreachable, mis-modeled, or blocked by testbench sequencing gaps.
What to observe
Coverage growth trend flattens below target despite rising simulation count and seed diversity.
Common traps
Pursuing random seed volume instead of root-causing unreachable cross bins.
Ignoring illegal-bin and ignore-bin misuse that distorts closure perception.
Forcing closure with exclusion waivers without scenario-level evidence.