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NSITEXE Selects ImperasDV for Automotive Quality RISC-V Processor Functional Design Verification

Imperas RISC-V Reference Model, Test suites and Verification IP for advanced ‘lock-step-compare’ Processor Verification including Asynchronous events and Coverage Analysis

NSITEXE and Imperas

Oxford, United Kingdom – May 24th, 2022 – Imperas Software Ltd., the leader in RISC-V simulation solutions, today announced that NSITEXE, Inc., a group company of the DENSO Corporation that develops and sells high-performance semiconductor IP for automotive applications, has selected ImperasDVTM for advanced RISC-V processor hardware design verification. This expands and extends the use of Imperas simulation technology, models, verification IP and tools by NSITEXE for the next generation of 64bit RISC V based designs featuring vector accelerators for AI (Artificial Intelligence) automotive applications with verification leading to the level required to achieve ISO 26262 ASIL D.

RISC-V is an open standard ISA (Instruction Set Architecture) that allows processor developers to optimize the configuration with both standard extensions and custom instructions. The recently ratified RISC-V Vector Extensions supports the compute requirements for hardware accelerators for applications involving linear algebra, which is well suited for the emerging AI algorithms and workloads in advanced automotive applications.

ImperasDV is the integrated solution for RISC-V processor verification that provides an adaptable framework based on the open standard RVVI (RISC-V Verification Interface) that supports the core RTL verification with the Imperas reference model in a ‘lock-step-compare’ methodology in addition to test suites and other verification IP. ImperasDV covers the verification tasks for implementations that range from basic controllers through to advanced designs featuring vector extensions, privileged mode security protections, multi-hart, and custom extensions. In addition, the freedom of the open standard ISA of RISC-V is enabling advanced processor technology in many new application areas with developers exploring techniques such as superscalar, out-of-order execution, multi-threading, heterogeneous multi-core and processor arrays plus other new and creative approaches for the next generation of domain specific devices. ImperasDV complements the verification tasks for development teams at the forefront of processor exploration.

“The flexibility of the RISC-V ISA coupled with the performance of vector extensions is an ideal starting point for AI accelerators for automotive applications,” said Hideki Sugimoto, CTO of NSITEXE, Inc., a group company of DENSO Corporation. “To address the verification requirement for our next generation of processors, we have developed an optimized verification flow with ImperasDV that our design team set up with detailed configuration options to deliver on their comprehensive verification plans that provides the industry leading quality our customers expect.”

“The open ISA of RISC-V is enabling a new wave of processor design innovation across the spectrum of compute requirements in almost all market segments,” said Nobuyuki Ueyama, President of eSOL TRINITY Co., Ltd. “High quality processor verification is not a simple task, but the ease of use and configurable approach with RVVI offered by ImperasDV enables the eSOL TRINITY team to support the expert design teams at NSITEXE and other leading adopters of RISC-V in Japan.”

“The open standard ISA of RISC-V is enabling a fundamental shift in processor development, with developers able to explore and innovate solutions with optimized solutions for targeted applications,” said Simon Davidmann, CEO at Imperas Software Ltd. “The flexibility of RISC-V on the design side has a direct impact on the verification task, and since the value-added features are central to the development, we developed ImperasDV to be adaptable for all implementations to allows our customers and users to verify state-of-the-art designs independently. NSITEXE are pioneers in developing advanced RISC-V vector accelerators for AI, and we are pleased to see the Imperas technology and ImperasDV supporting the quality requirements for automotive applications.”


ImperasDV is available now, with more details available at

The ImperasDV RISC-V processor verification technology is already in active use with many leading customers, some of which have working silicon prototypes and are now working on 2nd generation designs. These customers, partners and users span the breadth of RISC-V adopters from open source to commercial; research to industrial; microcontrollers to high performance computing. A select sample of these include - Codasip, EM Microelectronics (Swatch), NSITEXE (Denso), Nvidia Networking (Mellanox), OpenHW Group, MIPS Technology, Seagate Technology, Silicon Labs, and Valtrix Systems, plus many others yet to be made public.

The open standard RVVI (RISC-V Verification Interface) provides the essential guidelines for the infrastructure around the processor testbench that supports the growing ecosystem of Verification IP for RISC-V processor verification. The new RVVI open standard and methodology, is based on an open specification ( and can be adapted to any configuration permitted within the RISC-V specifications. In adopting the RVVI standard, developers can leverage all the common components off the shelf and explore additional options with reusable Verification IP across projects.

The free riscvOVPsimPlus package, including the Imperas RISC-V Reference Model, sample test suites and instruction coverage analysis, including updates for the latest RISC-V ratified specifications is also available on OVPworld at


RISC-V Days Tokyo 2022 Spring
Mr. Shuzo Tanaka, eSOL TRINITY Co., Ltd. will deliver the Imperas Platinum talk on RISC-V verification at RISC-V Days Tokyo 2022 Spring, May 31 to June 2, 2022.

RISC-V high quality verification with new open standard RVVI and ImperasDV
Abstract: RISC-V is extending the design freedoms for SoC developers with optimized processors. This talk outlines RVVI (RISC-V Verification Interface), an open standard interface for RISC-V processor verification with efficiency, reusability and flexibility. Highlights will cover examples of testing some popular open-source IP cores, and guidance for new processor DV projects.
     •    Speaker:        Shuzo Tanaka, eSOL TRINITY Co., Ltd.
     •    Co-Author:    Simon Davidmann – Imperas Software Ltd
     •    Co-Author:    Lee Moore – Imperas Software Ltd
     •    When:             May 31 2022 at 4:30PM JST (GMT+9)
     •    Where:           Tokyo, Japan.

For more information and registration please visit


eSOL TRINITY (TRINITY) is a premier solutions provider for the design and development of embedded software. TRINITY's comprehensive solution consists of consultation and professional services, tools, and fostering of engineering experts. With its rich experience in automotive market and its wide range of expertise including Cyber security, Functional safety, process development and software and hardware development environment for RISC-V, TRINITY contributes to improvement of software quality and reduction of development costs for customer. TRINITY was established in 2015 as a wholly owned subsidiary of eSOL Co., Ltd., the leading provider of real-time embedded software solutions. For more information about eSOL TRINITY, please see



About Imperas

Imperas is the leading provider of RISC-V processor models, hardware design verification solutions, and virtual prototypes for software simulation. Imperas, along with Open Virtual Platforms (OVP), promotes open-source model availability for a spectrum of processors, IP vendors, CPU architectures, system IP and reference platform models of processors and systems ranging from simple single core bare metal platforms to full heterogeneous multicore systems booting SMP Linux. All models are available from Imperas at and the Open Virtual Platforms (OVP) website at

For more information about Imperas, please see Follow Imperas on LinkedIntwitter @ImperasSoftware and YouTube.


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