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EDA TOOLS / VERIFICATION / Hetu-Formal

Hetu-Formal

Native formal property verification and equivalence checking  ·  part of the WIOWIZ verification flow

Proof, not an unexplained pass

Hetu-Formal asks whether a temporal or structural property holds for every behavior the model allows, and returns either an attributable proof or a concrete counterexample. Built around a controlled proof spine of AIG construction, Tseitin CNF conversion, a native CDCL SAT solver and k-induction, it keeps proof semantics, counterexample generation and solver evidence consistent across property verification, equivalence, protocol, security and coverage applications.

BMCK-inductionIC3/PDRCEGARLivenessSVA observersEquivalenceProtocolFormal UNR

What it does

Property and assertion proof

Compiles a SystemVerilog Assertion subset into executable observer FSMs, proving invariants and solving cover goals with clean unsupported-property diagnostics.

Model checking

Bounded model checking with concrete counterexample traces, k-induction with base and step evidence, and IC3/PDR unbounded safety with a certified inductive invariant.

CEGAR and liveness

Localization-based CEGAR built over the IC3 flow, plus liveness-to-safety lasso reasoning that returns a proof or a stem-and-loop starvation witness.

Equivalence checking

Sequential RTL-to-RTL validation, frozen-symbol datapath scoreboarding and datapath validation against integer and fixed-point reference expressions, including narrow multiply and saturation.

Connectivity and protocol

AXI, AHB, APB and generic ready/valid rule libraries bound to mapped design signals on the master or slave side, with environment assumptions constraining legal behavior.

Coverage and unreachability

Cover-property reachability with witnesses and formal unreachable analysis applied to real SoC unreachable-code points, feeding coverage closure evidence.

Security non-interference

Information-flow verification using two-copy models to test non-interference between secret sources and observable outputs.

Testbench quality

Vacuity, over-constraint, weak cone-of-influence and mutation-escape analysis so the proof environment itself is checked, not trusted.

Fenced SMT and provenance

A fenced Z3 SMT flow for supported integer and non-NaN IEEE-754 problems, returning UNKNOWN rather than a fabricated proof, with structured evidence JSON on every run.

Support

Stage Verification, formal property verification and equivalence checking
Proof engines Bounded model checking, k-induction, IC3/PDR, localization CEGAR, liveness-to-safety, native CDCL SAT with optional CaDiCaL agreement, fenced Z3 SMT
Applications Property/assertion proof, model checking, LEC equivalence, connectivity and protocol, coverage and formal unreachability, security non-interference, low-power sequencing, functional-safety fault classification
Property input SystemVerilog Assertion subset (|->, |=>, ##n, disable iff, $past, $rose, $fell, $stable, selected s_eventually), protocol rule libraries, environment assumptions
Design inputs RTL and mapped netlist within the supported Verilog subset, VCD-seeded simulation-to-formal initialization with conditional-verdict labelling
Outputs Structured evidence JSON with engine, solver, depth, verdict and witness/proof metadata; concrete counterexample traces; certified invariants; formal UNR results for coverage closure
PDK / technology Not required, operates on RTL and netlist (technology independent)
Flow CLI-first native stage in the WIOWIZ verification flow, deterministic and evidence-sealed for regression and CI

Linux release

Hetu Formal 0.26.0 for Linux x86_64 includes the command-line engine and native Studio GUI. The GUI provides RTL import, command and argument controls, Run, Stop, result views, engine log and transcript.

Hetu Formal Studio on Linux with command, arguments, Run and Stop controls

SHA-256
57063d5cd976e8c84bd2080125223bed0c937c1d7c0673bc3f67028fa829203e

Verify after download: sha256sum hetu-formal-0.26.0-linux-x86_64.tar.gz

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