Predictable formal verification sign-off for critical digital IP and SoCs

We help RTL teams reduce schedule uncertainty and uncover simulation-resistant corner cases through a systemized delivery model refined across 325+ formal verification projects

  • Predictable milestones and clear sign-off criteria
  • Corner-case bugs that are hard to reach in simulation
  • A dedicated team 100% focused on formal verification

What our clients value

What our clients value in our formal verification sign-off

LUBIS EDA in numbers

LUBIS formal verification sign-off in numbers

Who this formal verification sign-off service is for?

Typical situations

A block is on the critical path and tape-out dates can’t slip.

Complexity is rising faster than your ability to hire deep formal expertise.

You simulate heavily, but you still worry about rare corner cases.

Formal exists, but bandwidth, structure, or convergence is the bottleneck.

What are your high-risk blocks?

The problem: verification is now the schedule bottleneck

As designs get more complex and schedules get tighter, the hardest bugs show up late, often in scenarios that testbenches don’t reach.

Formal verification can close that gap, but it only becomes predictable when it’s executed with the right structure: clear sign-off targets, sound assumptions, strong abstractions, and disciplined convergence.

What we do: Formal Verification Sign-Off

Outcome: a verified IP block / subsystem with agreed sign-off criteria and the transparency to defend sign-off internally.

What you receive

Formal sign-off plan and scope definition
Property plan + assumptions/constraints approach
Coverage & convergence tracking
Results documentation / sign-off report
Reusable verification artifacts (as agreed)

How it works: Plan → Prep → Execute → Sign-off

Our delivery model is designed to make formal work predictable and visible — without hero-based consulting:

The LUBIS EDA Formal flow for formal verification sign-off service

You bring the designs that are hard to verify with simulation alone.
Input: RTL design, specifications, known risks, and verification goals

We align on target behaviors, bug classes, priorities, and acceptance criteria.
You get: scope, milestones, definition of done, and sign-off targets

We create the formal environment needed for convergence.
You get: abstractions, constraints, environment modeling, and a stable setup

We drive convergence, close coverage goals, and investigate failing properties.
You see: progress, bug findings, coverage status, and remaining risks

We document results and provide a clear formal verification sign-off recommendation.
You receive: final report, findings, limitations, and reusable verification artifacts where agreed

Why LUBIS EDA?

Specialist at scale

A layered team of verification specialists across every depth of expertise.

Specialist at scale

We sign-off important IP

Sign-off quality for the IP that protects and differentiates your product.

We sign-off important IP

Our sign-off maturity flow

A proven, repeatable flow that drives predictable quality and coverage.

Our sign-off maturity flow

Engagement models

LUBIS EDA formal verification sign-off engagement model fixed

Objections you might have about a formal verification sign-off

“We can do it ourselves.”

Many teams can. The question is whether it will be fast enough on the highest-risk blocks without pulling experts from everything else.

“We already simulate a lot.”

Simulation is essential. Formal systematically explores scenarios that are unrealistic to cover with testbenches alone.

“Formal is too hard / doesn’t scale.”

Formal scales with the right structure — abstractions, constraints, and a clear sign-off methodology.

50% of respins are due to functional bugs

Your time and budget are limited. To avoid bug escapes and reach the best possible quality for tape out, make formal sign-off a priority of your verification strategy.

Not experts or not willing to do it within your team? Having a custom design that comes with special needs? No problem, we will do it for you. We have done it for others across AI, ML, automotive and more, including RISC-V players.

Gain confidence in your design and tape out in time

Square screen with various tabs symbolizing the LUBIS EDA App Builder

For formal sign-off, we target simulation-resistant bugs using formal verification supported by the LUBIS EDA Formal Verification Toolbox to accelerate the process and improve quality.

A person painting a ladder between two mountains, symbolizing the help with tape-out from LUBIS EDA to customers.

It is the combination of multiple verification techniques, including formal verification, that will take you one step closer to quality tape out.

Target hit in the center by an arrow and a missile and 2 people are next to it, illustrating that LUBIS EDA helps its customers to meet their schedule.

By the way, 66% of ASIC projects are behind schedule. We bet you do not want to be one of them. Count on us to help you stick to your budget and timeline.

Square screen with various tabs symbolizing the LUBIS EDA App Builder

It is the combination of multiple verification techniques, including formal verification, that will take you one step closer to quality tape out.

Target hit in the center by an arrow and a missile and 2 people are next to it, illustrating that LUBIS EDA helps its customers to meet their schedule.

For formal sign-off, we target simulation-resistant bugs using formal verification supported by the LUBIS EDA Formal Verification Toolbox to accelerate the process and improve quality.

A person painting a ladder between two mountains, symbolizing the help with tape-out from LUBIS EDA to customers.

By the way, 66% of ASIC projects are behind schedule. We bet you do not want to be one of them. Count on us to help you stick to your budget and timeline.

Gain confidence in your design and tape out in time

Illustration of the LUBIS EDA planning phase
Illustration of the LUBIS EDA feedback cycle
LUBIS EDA sign-off illustration that adds the missing AIP to the design puzzle

Plan

Execute

Sign off

We identify high-risk blocks, define verification targets, scope efforts, and set up accurate KPIs.

We follow and complete the verification plan defined during setup. We send you weekly feedback and on-the-spot bug reports.

We hand out to you the Assertion IP (AIP) that accelerates run-time and integrates with existing regression tests to validate that a code change does not impact the existing functionality of the final product.

Illustration of the LUBIS EDA planning phase

Plan

We identify high-risk blocks, define verification targets, scope efforts, and set up accurate KPIs.

Illustration of the LUBIS EDA feedback cycle

Execute

We follow and complete the verification plan defined during setup. We send you weekly feedback and on-the-spot bug reports.

LUBIS EDA sign-off illustration that adds the missing AIP to the design puzzle

Sign off

We hand out to you the Assertion IP (AIP) that accelerates run-time and integrates with existing regression tests to validate that a code change does not impact the existing functionality of the final product.

Based on your design stage

Formal verification methods can help you at all design levels. You can count on us at every stage.

Design bring-up

Design and specification are still in process during design bring-up.

We provide your design team with an Assertion IP (AIP) based on your specifications.

You then use that AIP to verify that new changes do not affect the existing functionality of your design. You also use it to identify specification mismatches in order to update the AIP according to the changes.

Design verification

When design and specifications are developed beforehand, we provide an AIP to validate the correct implementation of specified features.

Bug Hunting

We assess and analyze specific and hard-to-verify features based on the project scope and verification plan.

IP redesign

The demand for IP redesign has become standard.

Continuously adding new functionalities to the IP results in growing design complexity. You need to refactor your IP and improve performance to preserve all existing functionalities (documented or not).

Industrial case study

Compute Cores

RISC-V Core

RISCV instruction set is an open-source ISA based on RISC principles and is being widely used in many areas due to the flexibility and modularity it offers. Formal verification became a necessity due to the increased usage of RISCV cores in many critical domains.

The design that was verified is a RISC-V base model (RV32i)

Bug Findings

Over 50 bugs were found during the first round of verification of this design in several instructions.

The bugs that were found were due to wrong execution of instructions, wrong exception handling and violation of the standard ISA description of the instructions.

The general verification setup around the RISC-V core

Bug 1

A bug was found in the BLT instruction where the design generates an exception when it should not. The instruction should check if register rs1 is less than rs2, if the condition holds true, then jump to the target address. However, the design was calculating the target address before evaluating if the condition is true which resulted in a misaligned address exception to be asserted, resulting in wrong values in some of the CSRs.

Bug 2

A bug was found in the JALR instruction where the design wrongly writes the fetching address of the JALR instruction to the register file in case a misalignment exception. The design fetches the JALR instruction from address 0x84 where it calculates the target address. In case of a misalignment, a misalignment exception should be generated and the JALR should not take effect. The design was correctly generating a misalignment exception, but it was wrongly writing the fetching PC value to the destination register.

Need us to sign-off your design?

Bring one critical IP block and we’ll outline a formal verification sign-off plan for you.

Training Topics

  1. Abstraction vectors (time, functionality)
  2. AIP for protocols
  3. AIP orchestration
  4. BMC & IPG, invariants
  5. Codestyle
  6. Completeness
  7. Liveness property, safety property
  8. Non-determinism (abstraction technique)
  9. Response generation (abstraction technique)
  10. Scoreboard (abstraction technique)
  11. Signal cutting, blackboxing
  12. State space explosion and mitigation techniques
  13. SVA fundamentals
  14. Whitebox checking, blackbox checking, greybox checking
  15. Witness, vacuity, reachability

Become a leader in formal verification