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constrained random simulation

Concept WIKI v1 · 7/17/2026

Constrained random simulation is a hardware verification approach in which input stimuli are generated randomly while satisfying declaratively specified input constraints, and the resulting stimuli are applied in simulation to validate design properties. The cited source emphasizes that effectiveness depends on both constraint-solver performance and the distribution of generated solutions, especially for mixed Boolean/integer variable domains.

Constrained random simulation

Constrained random simulation is a technique used in hardware verification in which input stimuli are generated randomly, subject to declaratively specified input constraints, and then applied in simulation to validate design properties.[1]

The cited source describes constrained random simulation as a main workhorse in hardware verification flows.[1] In this workflow, two factors are highlighted as especially important to overall efficiency:[1]

  • the performance of the constraint solver
  • the distribution of the generated solutions

The same source discusses this problem in the context of stimulus generation over mixed Boolean/integer variable domains.[1] It also presents a hybrid solver based on Markov-chain Monte Carlo methods as one proposed approach for achieving good performance and solution distribution.[1]

Key aspects

  • Randomized stimulus generation: stimuli are generated randomly rather than enumerated manually.[1]
  • Constraint-driven inputs: generated stimuli must obey specified input constraints.[1]
  • Simulation-based validation: the generated inputs are used to validate design properties by simulation.[1]
  • Solver and distribution quality matter: efficiency depends not just on finding solutions, but also on how quickly they are found and how they are distributed.[1]

Scope in the evidence

The available evidence characterizes constrained random simulation primarily through its role in hardware verification and stimulus generation, and through the importance of constraint solving and solution distribution.[1]

CITATIONS

5 sources
5 citations
[1] Constrained random simulation generates input stimuli randomly while requiring them to satisfy declaratively specified input constraints, and applies those stimuli in simulation to validate design properties. Stimulus generation for constrained random simulation
[2] The cited source describes constrained random simulation as a main workhorse in hardware verification flows. Stimulus generation for constrained random simulation
[3] Overall efficiency depends critically on constraint-solver performance and on the distribution of generated solutions. Stimulus generation for constrained random simulation
[4] The discussed constraint-solving problem is for stimulus generation over mixed Boolean/integer variable domains. Stimulus generation for constrained random simulation
[5] The cited paper proposes a hybrid solver based on Markov-chain Monte Carlo methods with good performance and distribution. Stimulus generation for constrained random simulation