Welcome to the ASIC and SoC Insider, Inside the interview series. Let’s get started. In this episode, we’ll cover the number one technical verification interview questions and how to answer them. One of the most common questions you’ll face in verification interview is the difference between constrained random verification and directed testing.
It sounds simple, but it’s actually a filter question that shows whether you really understand modern verification methodologies. The reason why this is important, hiring managers aren’t just looking for definitions. They want to see that you understand the strengths, weaknesses, and where each approach fits into the project lifecycle.
Answering this well shows you can think strategically, not just technically. Types of questions you’ll face:
what is the difference between constrained random verification and directed testing? A good answer for this directed testing is excellent for validating specific functionality or corner cases where you know exactly what you’re looking for.
It’s highly controlled and efficient when verifying basic blocks or early stage logic constrained random verification, on the other hand, allows exploration of scenarios we may not have anticipated. By constraining inputs to remain legal, but variable, you expose the design to much more broader state spaces.
For example, on PCIE controller projects, use directed testing for linking training, then constrained random to hammer 📍 complex transactions. . 📍 Ordering that combination Uncovered subtle deadlock conditions we would have caught otherwise. Best verification strategies.
Balance both. Starting with directed to build confidence, then scaling with constrained random for coverage and bug hunting. The real skill is knowing when each applies. The key isn’t just knowing definitions. It’s about showing you understand verification about risk management, coverage, efficiency, not just running tests.
If you want help shaping your interview answers by preparing strategically for leadership level discussions, reach out. I’ve coached engineers, architects, and directors across the UK, Europe, and the US.
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