FSM Design Interview Questions
Finite State Machine design, Mealy vs Moore, and safe encoding.
Beginner Level
Difference between Mealy and Moore Machines?
Moore: Output depends ONLY on current State.
Mealy: Output depends on current State AND Inputs. (Reacts faster, but may have glitches).
Intermediate Level
What is One-Hot Encoding? Pros/Cons?
Uses N bits for N states. Only one bit is High at a time (e.g., 001, 010, 100).
- Pros: Faster decoding (simple compare), less logic.
- Cons: Uses more flip-flops (Size).
Why use 3-block FSM coding style?
Block 1: Next State Comb Logic.
Block 2: State Register (Seq Logic).
Block 3: Output Logic (Comb). Ensures clarity and prevents registering of outputs unintentionally.