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STIMSMITH

Vector Extensions

Concept WIKI v1 · 5/26/2026

Vector Extensions are treated in the provided evidence as a RISC-V processor feature area requiring targeted verification and coverage closure. In RISC-V verification flows, ImperasTS-VECT provides directed test suites for vector extensions, complementing constrained-random stimulus and helping close coverage gaps.

Overview

Vector Extensions are identified in the evidence as a RISC-V processor feature area that verification teams may need to validate explicitly. They appear alongside other RISC-V features and specification areas such as MMU, PMP, ePMP, and hypervisor support in verification planning and compliance-oriented flows. [C1]

Role in RISC-V verification

The evidence describes vector extensions as an area addressed by targeted verification suites. In the ImperasTS family, TS-VECT is specifically described as a targeted suite for vector extensions. [C2]

Directed suites such as TS-VECT are used as part of a hybrid coverage-closure methodology: constrained-random stimulus explores broad behavior, while directed suites target areas where random stimulus may leave gaps. [C3]

Configuration and applicability

The test suites for vector, MMU, PMP, and ePMP are described as configurable to match the user's RISC-V processor. This means vector-extension validation is presented as implementation-aware rather than one-size-fits-all. [C4]

Use in coverage closure

The provided flow recommends applying targeted ImperasTS suites, including those for vector extensions, where coverage gaps remain. This places vector-extension testing in the later, directed phase of a hybrid strategy after broader exploration and coverage analysis. [C5]

Verification methodology context

The broader methodology combines:

  • constrained-random stimulus, described using STING;
  • directed suites, including ImperasTS-VECT for vector extensions;
  • functional coverage analysis;
  • deterministic replay of failing cases; and
  • portability across simulation, emulation, FPGA prototyping, and silicon. [C3][C5][C6]

Within this methodology, vector extensions are one of the targeted RISC-V feature areas that can require explicit directed testing to support coverage closure and compliance-oriented validation. [C1][C2][C5]

CITATIONS

6 sources
6 citations
[1] Vector extensions are identified as a RISC-V feature/specification area covered by verification flows. source
[2] ImperasTS-VECT is a targeted test suite for vector extensions. source
[3] Hybrid RISC-V verification combines constrained-random stimulus with directed tests to close coverage gaps. source
[4] The vector, MMU, PMP, and ePMP test suites are configured to match the user's RISC-V processor. source
[5] Targeted ImperasTS suites should be applied for vector extensions where coverage gaps remain. source
[6] The described verification methodology includes portability across simulation, emulation, FPGA prototyping, and silicon. source