RISC-V architecture enjoyed a rapid growth in the last few years, so it’s a good time to explore its architecture, usage, and advantages. There are essentially two CPU choices for SoC designs: ARM or RISC-V. Each of these two CPU types are tied to differing philosophies about open-source models, but they also differ on their performance, pricing, royalties, and support. In this article we will provide an overview of RISC-V IP core vendors and describe the difference between their offerings.

What is RISC-V?

RISC-V is a very successful CPU core and expected to be widely used in the future. Currently, the usage of RISC V is expected to increase to over %13 of the market share in 2025. RISC-V is an open-source ISA which doesn’t require any licensing. At the moment, there are 36 companies that support RISC V ISA.

RISC-V (by the way, pronounced as “risk-five”) is an ISA or Instruction Set Architecture, which is a very abstract model of computer architecture that can be used to define internal design of the CPUs. The project started at the university of California in 2010 by volunteer contributors and is owned by RISC-V Foundations.

As seen in the above block diagram, the RISC architecture uses registers, making it very fast and simple. RISC-V supports 32-bit, 64-bit and 128 bit architectures.

Large Companies Support RISC-V

Although, RISC-V seems to be an opportunity for small-mid size fabless companies, there are numerous large companies that plan on using RISC V core in different market segments and are taking active part as members in RISC-V organization group. For example:

• Google has developed the Titan M2 security module for the Pixel 6 and is very likely to use it in their other embedded applications (such as glass, smart robots etc.).

• Seagate announced in December 2020 that it developed two RISC-V general-purpose cores for use in upcoming controllers for its storage devices.

• Nvidia plans to use RISC-V to replace their Falcon processor on their GeForce graphics cards.

• Huawei’s company HiSilicon release a TV chipset based on RISC V architecture.

• Intel is exploring RISC-V architecture for their supercomputer and plans to contribute to RISC-V growth.

RISC-V vs ARM

Closed vs open-source hardware is at the heart of the ARM vs RISC-V differences. RISC-V does not require licensing, royalties, or other fees. Additionally, RISC-V cores can be customized according to your company’s needs. Any CPU, whether custom or not, can now be made easily.

ARM, on the other hand, requires an IP core license approval, which costs $10-100K. Moreover, if you want to change anything in the design, you’ll be charged a fee.

Today’s basic working assumption is that one can choose RISC V over ARM to achieve a cheaper, modular design that can be integrated easily into SoCs.

To summarize the differences between ARM and RISC- V:

IP Cost: The open-source RISC V cores are free to use, however, if you choose to use an RISC V core from one of the companies that has an added value you will need to pay a license fee. For ARM cores, all IP products have a license fee.

Royalty: if you want to use ARM you need to pay a royalty (percent) per every produced chip. No royalty is needed for RISC V.

Technical Support: As for today, ARM has more support resources to help engineers with their designs.

Proven Record: ARM cores have many more hours of usage in products than RISC-V products. ARM cores are used in cars, mobile phones and in satellite products.

Commercial vs. open-source IP licensing models. (Image: RISC-V International)

RISC-V IP Cores Vendors

(send us an email to update the list)

The following list consists of companies that market and sell RISC-V IP cores for ASIC, SoC or FPGA development.

Rydev

Rydev develops silicon-tested ultra-low-power RISC-V based microcontroller on a 0.18um and 65nm CMOS commercial processes.

• Silicon-tested ultra low power (48.31 pJ/cycle @1MHz per core on 0.18um commercial process.
• Ultra-Compact RISC-V 32RVI compatible microcontroller: dual and single core IP solutions (less than 32k gates per core)
• Include SPI, Bootstrap, UART and SRAM memory controllers.
• Full instruction-set implementation (32RVI 32-bit base integer) with custom special GPIO instructions
• IP is capable of replacing 8 and 16-bit microcontroller solutions while being flexible and expandable to 32-bits, maintaining complete compatibility to RISC-V open-source toolchains.

Website: https://rydevinc.com/

CAST

CAST develops, sells, and supports digital Silicon IP Cores for ASICs or FPGAs. Electronic system designers use these to shorten development time and lower production risk. CAST was founded in 1993 and has always focused on reusable IP cores. We have helped thousands of companies worldwide gain a competitive edge, and they have built our IP into billions of shipping product units. One-third of our sales are to repeat customers.

Website: https://www.cast-inc.com/

SiFive

A semiconductor company that develop three distinct processor families based on the RISC-V ISA: SiFive essential, SiFive Performance, SiFive intelligence.

Website: https://www.sifive.com/

Western Digital

It’s an American hard drive and integrated circuits manufacturer. There are four RISC V cores have been developed by the company: SweRV Core EHX3, SweRV Core EH1, SweRV Core EH2,  and SweRV Core EL2.

Website:  https://www.westerndigital.com/company/innovation/open-source/risc-v

Syntacore

Syntacore is a RISC-V processor IP specialist. It creates flexible, highly-efficient microprocessor cores that help customers to design unique solutions for the IoT, data storage and processing, embedded systems, cognitive, machine learning and artificial intelligence applications. The company develop main 7 types of RISC V products from SCR1 to SCR7.

Website: https://syntacore.com/

RIOS

Founded in 2019 as part of Tsinghua-Berkeley Shenzhen Institute (TBSI), the RISC-V International Open Source Laboratory (RIOS Lab) began its journey of bringing the research effort of RISC-V CPU with its software and hardware ecosystems from UC Berkeley to the rest of the world. As a premier member of RISC-V Foundation, RIOS is aiming to demonstrate its commitment to the open source platform for chip developers with far more economical and efficient technology.

Website: https://rioslab.org/

FutureWei

Founded in 2001, Futurewei Technologies is dedicated to pursuing openness in Research & Development (R&D) by embracing Open Innovation Model. We strive to share ideas and knowledge with technology communities to open and new business opportunities.

Website: https://futurewei.com/

Andestech

Andes Technology USA Corp., the headquarters of North America operations of Hsinchu, Taiwan-based Andes Technology Corporation, was established in 2015 as a California corporation coincident with Andes Technology Corp. becoming a Founding and Premier Member of RISC-V International. Recognizing that the RISC-V instruction set architecture (ISA) could become a major new product line for the company, the U.S. operation was formed to be nearby early customer adopters of the new ISA. The U.S. subsidiary established an R&D lab shortly thereafter and began developing architectures for the high-end RISC-V processors

ISCAS

The Institute of Software, Chinese Academy of Sciences (ISCAS) is a research base that focuses on the research and development on theories of computer science and leading edge technologies of software.

Website:  http://english.is.cas.cn/au/bi/

UniSoc

UNISOC, a leading fabless semiconductor company based in China. For us, building a foremost ecosystem is the core strategy, 5G and AI are the two main technologies, Value, Future and Service are the three orientations. We are empowering personalized experience and intelligent society.

Website: https://www.unisoc.com/

 Ventana Micro

Headquartered in Cupertino, Ventana Micro Systems Inc. was founded in 2018 to revolutionize the processor market by offering high-performance, extensible and secure compute chiplets based on RISC-V’s open architecture. Ventana delivers the highest performance RISC-V CPUs with extensible instruction set capability delivered in the form of multi-core chiplets or core IP for high-performance applications in the cloud, enterprise data center, hyperscaler, 5G, edge compute, AI/ML and automotive markets.

Website: https://www.ventanamicro.com/

Arilinc

Optimized RISC-V Processor Technology For Performance, Power, Area, Security & Safety in embedded computing SOCs and domain specific architectures Venture Backed Start-Up Proven RISC Microarchitecture Team Optimized Architecture: Performance, Power, & Area (PPA) Designed for Security & Safety.

Website: https://www.arilinc.com/

Cortus

Cortus is a fabless semiconductor manufacturing company. Cortus provides IC devices from a simple MCU to a high-end SoC based around its broad IP portfolio which includes processor, digital, analog, mixed-signal, RF and security IP; in many areas such as Automotive, IoT/NB-IoT and Industrial. Over 10 billion devices have been manufactured containing Cortus processors and IP. Cortus is a Platinum Founding Member of the RISC-V Foundation and strategic member of RISC-V International.

Website: https://cortus.com/

Axelera

Axelera AI is developing a game-changing hardware and software platform for AI that will make the industry more integrated, efficient and accessible. With growing privacy, security and bandwidth concerns in mind, much of this data is increasingly processed close to its origin, or “the edge.” Axelera AI is working to deliver solutions that meet this demand, empowering AI applications at the edge and datacenters.

Website: https://www.axelera.ai/

Clue

Clue, is research, design, and manufacture innovative electronic systems for the aerospace industry.  The company matches world-class engineering and the start-up world’s lean approach drive for innovation. Our inspiration comes from disruptive technologies, no matter what the original field of application or market is. We question everything, pursuing efficiency and robustness.

Website: https://www.clue.aero/

PULP

An open, scalable hardware and software research and development platform with the goal to break the energy efficiency barrier within a power envelope of a few milliwatts, as well as satisfy the computational demands of IoT applications requiring flexible processing of data streams generated by multiple sensors, such as accelerometers, low-resolution cameras, microphone arrays and vital signs monitors.

Website: https://pulp-platform.org/

Roa Logic

Roa Logic BV specializes in the development of Intellectual Property Cores for FPGA and ASIC, with a strong focus on the embedded market. Roa Logic offers the RV12, which is a highly configurable single-issue, single-core RV32I, RV64I compliant RISC CPU intended for the embedded market. The RV12 is a member of the Roa Logic’s 32/64bit CPU family based on the industry standard RISC-V instruction set-

Website: https://roalogic.com/