Explain timing and testability concepts
Company: Arm
Role: Backend Engineer
Category: Software Engineering Fundamentals
Difficulty: medium
Interview Round: Onsite
For a digital implementation or backend-focused interview, explain the following concepts:
1. What are **setup time** and **hold time**?
2. How does **clock skew** affect setup and hold timing?
3. What are common ways to fix **setup violations** and **hold violations**?
4. What do **scan**, **DFT (Design for Test)**, and **MBIST** mean, and why are they used?
Give definitions, describe the practical impact on chip timing closure and testability, and mention common engineering trade-offs.
Quick Answer: This question evaluates a candidate's understanding of digital timing and testability concepts—specifically setup and hold timing, clock skew impacts, mitigation of setup/hold violations, and test methodologies such as scan, DFT and MBIST—within backend digital implementation contexts.