SystemVerilog Interview Questions: A Comprehensive Guide

Basic Level Questions

1. Data Types:

   • Explain the difference between bit and logic data types.
   • Discuss the concept of 2-state and 4-state logic.
   • Explain the difference between integer and int.
   • Differentiate between packed and unpacked arrays.
   • Explain dynamic and associative arrays and their use cases.
   • Discuss the difference between structures and unions.

2. Operators and Expressions:

   • Explain the difference between === and == operators.
   • Discuss the use of bitwise operators (&, |, ^, ~, <<, >>).
   • Explain the concept of reduction operators (&, |, ^).
   • Discuss the use of logical operators (&&, ||, !).

3. Tasks and Functions:

   • Differentiate between tasks and functions.
   • Explain the use of automatic storage type in tasks.
   • Discuss the concept of static and automatic functions.

4. Timing and Simulation:

   • Explain the use of #0 delay.
   • Discuss the difference between blocking and non-blocking assignments.
   • Explain the concept of simulation time and time units.

5. Generate Blocks:

   • Explain the purpose of generate blocks.
   • Discuss the generate and endgenerate keywords.
   • Provide examples of using generate blocks to create parameterized designs.

6. Interfaces:

   • Explain the purpose of interfaces in SystemVerilog.
   • Discuss the concept of modports and clocking blocks.
   • Provide examples of using interfaces to modularize designs.

7. Randomization:

   • Explain the use of rand and randc keywords.
   • Discuss the randomize() method and its arguments.
   • Explain the concept of constraints and their use in randomization.

8. Coverage:

   • Explain the concept of functional coverage and code coverage.
   • Discuss the use of covergroups and cover points to measure coverage.
   • Explain the difference between ignore and illegal bins.

9. DPI:

   • Explain the purpose of DPI.
   • Discuss the concepts of DPI import and export.
   • Provide examples of using DPI to interface with C/C++ code.

Intermediate Level Questions

1. Arrays and Queues:

   • Explain the difference between dynamic arrays and queues.
   • Discuss the operations on arrays and queues (push, pop, peek, etc.).

2. OOP Concepts:

   • Explain the concepts of inheritance, polymorphism, and encapsulation.
   • Discuss the use of super and this keywords.
   • Explain virtual functions and their role in polymorphism.
   • Discuss virtual interfaces and their use cases.

3. Constraints and Randomization:

   • Explain the use of std::randomize().
   • Discuss bidirectional constraints.
   • Explain how to disable constraints and randomization.
   • Discuss the use of :/ and := operators in randomization.

4. Scheduling and Simulation:

   • Explain the Verilog event scheduler.
   • Discuss the difference between @posedge and $rose.
   • Explain the concept of delta cycles.

5. Assertions:

   • Explain the purpose of assertions in SystemVerilog.
   • Discuss different types of assertions (immediate, concurrent, sequence).
   • Explain the implication operator and its use in assertions.

6. Testbench Architecture:

   • Explain the basic components of a SystemVerilog testbench (driver, monitor, scoreboard, etc.).
   • Discuss the layered architecture of a testbench.
   • Explain the concept of functional coverage driven verification.

Advanced Level Questions

1. Class-Based Testbenches:

   • Explain the advantages of class-based testbenches over module-based testbenches.
   • Discuss the use of OOP concepts in testbench design.

2. Constraint Solving and Randomization:

   • Explain the constraint solving algorithm used by simulators.
   • Discuss the impact of constraint complexity on simulation performance.

3. Formal Verification:

   • Explain the concept of formal verification.
   • Discuss the use of formal verification tools to prove design correctness.

4. Advanced Verification Techniques:

   • Explain the use of coverage-driven verification and constrained-random verification.
   • Discuss the use of functional coverage and code coverage to measure verification completeness.