What this tests
Constraint interviews evaluate whether you can describe a legal stimulus space without accidentally biasing, overconstraining, or slowing the solver. Familiar syntax is only the starting point.
Generate legal, useful stimulus
SystemVerilog Constraints Interview Questions
How to practice
Use this collection to progress from basic ranges and weighted distributions to relational arrays, temporal restrictions, address windows, and solver-sensitive problems. Before writing code, define the valid set and check edge cases such as empty ranges, overflow, modulo bias, or conflicting soft constraints.
Topic breakdown
What to be ready to explain
Ranges and distributions
Build legal ranges, weighted choices, alignment, and dependent-field relationships without hidden bias.
- inside
- dist
- Alignment
- solve before
Arrays and relationships
Express uniqueness, ordering, exact counts, and cross-element rules while keeping solver work bounded.
- foreach
- unique
- Array sizing
- Relational constraints
State and validation
Decide when stateful randomization or post_randomize is justified and prove the generated population is useful.
- rand_mode
- post_randomize
- Solver performance
- Coverage
Curated practice links
Questions to work through
Permanent bank numbers and direct links make it easy to continue in the live question bank.
- Q141Bias burst lengths by range
Explain the key Randomization and dist decisions, assumptions, and checks.
Constraints · Easy - Q527Constrain exactly K set bits
Explain the key Randomization and $countones decisions, assumptions, and checks.
Constraints · Easy - Q647Constrain unique increasing addresses
Explain the key Randomization and foreach decisions, assumptions, and checks.
Constraints · Easy - Q007Constrain a size-aligned address
Explain the key Randomization and Alignment decisions, assumptions, and checks.
Constraints · Easy - Q868Forbid consecutive POP commands
Explain the key Randomization and Sequence constraint decisions, assumptions, and checks.
Constraints · Easy - Q879Enforce uniqueness within each group
Explain the key Randomization and Conditional uniqueness decisions, assumptions, and checks.
Constraints · Medium - Q862Randomize weighted onehot-or-zero requests
Explain the key Randomization and Onehot decisions, assumptions, and checks.
Constraints · Medium - Q430Constrain a Gray-adjacent sequence
Explain the key Randomization and Gray code decisions, assumptions, and checks.
Constraints · Medium - Q695Constrain a bounded zig-zag address walk
Explain the key Randomization and Adjacent values decisions, assumptions, and checks.
Constraints · Medium - Q531Constrain a DMA transfer to one 4KB page
Explain the key DMA and Alignment decisions, assumptions, and checks.
Constraints · Medium - Q856Generate a temporal hazard-safe instruction stream
Explain the key Temporal hazards and Distribution decisions, assumptions, and checks.
Constraints · Hard - Q448Basic constraints
Explain the key Constrained randomization decisions, assumptions, and checks.
Constraints · Medium - Q568Soft constraints
Explain the key Constrained randomization decisions, assumptions, and checks.
Constraints · Medium - Q1022Distribution constraints
Explain the key Constrained randomization decisions, assumptions, and checks.
Constraints · Medium - Q224Solve before
Explain the key Advanced randomization decisions, assumptions, and checks.
Constraints · Hard - Q214Random dynamic arrays
Explain the key Advanced randomization decisions, assumptions, and checks.
Constraints · Hard - Q916Rand_mode
Explain the key Advanced randomization decisions, assumptions, and checks.
Constraints · Hard - Q029Generate a unique array with constraints
Explain the key Unique and post_randomize decisions, assumptions, and checks.
Constraints · Easy - Q030Allow exceptions in a unique-array constraint
Explain the key Unique and Exceptions decisions, assumptions, and checks.
Constraints · Medium - Q031Constrain transaction IDs to be unique
Explain the key Struct and Field uniqueness decisions, assumptions, and checks.
Constraints · Medium - Q762Solve N-Queens with column constraints
Explain the key Constraint randomization and Unique constraint decisions, assumptions, and checks.
Constraints · Medium - Q763Solve N-Queens with a board matrix
Explain the key Constraint randomization and Matrix decisions, assumptions, and checks.
Constraints · Hard - Q667Constrained Non-Overlapping DMA Bursts
Explain the key SystemVerilog constraints and DMA decisions, assumptions, and checks.
Constraints · Hard - Q391Constrain ten unique multiples of three
Explain the key Constraints and Unique decisions, assumptions, and checks.
Constrained Random · Easy - Q255Constrain exactly five changed bit positions
Explain the key Constraints and Hamming distance decisions, assumptions, and checks.
Constrained Random · Easy - Q648Constrain a nonzero 32-bit power of two
Explain the key Constraints and Power of two decisions, assumptions, and checks.
Constrained Random · Easy - Q466Do not repeat the previous five values
Explain the key Stateful randomization and post_randomize decisions, assumptions, and checks.
Constraints · Medium - Q487Constrain exactly one duplicated nonadjacent pair
Explain the key Relational constraints and Exact duplicates decisions, assumptions, and checks.
Constraints · Hard - Q1040Constrain exactly three nonoverlapping 110 patterns
Explain the key Pattern constraints and Exact count decisions, assumptions, and checks.
Constraints · Hard - Q535Constrain five non-overlapping address windows
Explain the key Constraints and Memory map decisions, assumptions, and checks.
SystemVerilog Constraints · Medium