VLSI DV Interview Puzzles · All levels

Distribution Puzzles (`dist`, `:=` vs `:/`)

Translate every dist clause into per-value effective weights, then normalize; mixing := and :/ changes granularity and can dramatically skew outcomes.

About this puzzle set

Translate every dist clause into per-value effective weights, then normalize; mixing := and :/ changes granularity and can dramatically skew outcomes.

Puzzles in this topic

diagram
1. Case A vs Case B vs Trap Variant  [Medium]
2. Small Range with := vs Large Range with :/  [Hard]
3. Loaded Die with Mixed Granularity  [Easy]
4. dist After Hard Pruning  [Hard]
5. Boolean dist Cascading into Value dist  [Medium]
6. Zero Weight Means Never Chosen  [Medium]

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

Constraint solve order and dependency flow

diagram
CONSTRAINT SOLVE ORDER

rand bit [3:0] burst_len;
rand bit [7:0] addr;

constraints:
  burst_len inside {[1:8]};
  addr % burst_len == 0;
  solve burst_len before addr;

solver picks burst_len first
            then chooses addr satisfying alignment

Explicit solve order reduces ambiguity in interview puzzles.

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