VLSI DV Interview Puzzles · All levels

Factory Override Puzzles

These puzzles test exact UVM factory behavior under competing overrides and mixed object creation styles. You must reason about precedence, path specificity, timing of override registration, and the critical difference between `create()` and direct `new()`.

About this puzzle set

These puzzles test exact UVM factory behavior under competing overrides and mixed object creation styles. You must reason about precedence, path specificity, timing of override registration, and the critical difference between `create()` and direct `new()`.

Puzzles in this topic

diagram
1. Type Override vs Instance Override Specificity  [Medium]
2. create() Honors Override, new() Bypasses  [Easy]
3. Replace Flag in Repeated set_type_override  [Medium]
4. Wildcard Instance Path Precedence  [Hard]
5. Component Override in build_phase  [Medium]
6. Override Timing Relative to create Calls  [Hard]

Work each puzzle before reading the solution: predict the exact output or answer, name the rule that governs it, then check yourself.

fork/join variants and completion semantics

diagram
FORK/JOIN INTERVIEW CHEAT MAP

fork
  task_a();   // 3 cycles
  task_b();   // 1 cycle
join
--> parent waits for all children

fork ... join_any
--> parent continues after first child completes

fork ... join_none
--> parent continues immediately; children run detached

Use wait fork; later to synchronize detached threads.

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