Glossary

RISC-V

What is RISC-V?

RISC-V is an open specification of an Instruction Set Architecture (ISA).

It describes the way in which software talks to underlying processor hardware. The RISC-V ISA is open so that anyone can build a processor that supports it. What RISC-V, however, is not a processor design or an open-source implementation. RISC-V based IP can be either open source or commercially licensed, such as Codasip processor IP.

The standard is maintained by RISC-V International, with members (including Codasip) coming from across the industry including software, systems, semiconductor and IP. The focus of member companies is on building a rich ecosystem of hardware and software that will rival or surpass that of alternative ISAs like Arm or x86.

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Why does RISC-V exist?

RISC-V was developed as an alternative to proprietary and closed-source ISAs like x86, Arm, and MIPS. Motivations and benefits of RISC-V include:

Design freedom: RISC-V is an open standard, therefore anyone can access and contribute to its specifications without any licensing or royalty fees. This openness fosters collaboration, innovation, and enables customization and specialization for specific applications or markets.
Research: RISC-V was created by researchers at the University of California, Berkeley. It allows students and researchers to experiment, explore new ideas, and develop innovative techniques without the limitations imposed by proprietary ISAs.
Customization and optimization: The RISC-V ISA is modular. Designers can select instruction set extensions and features based on their specific requirements. This flexibility enables customization and optimization for various applications, ranging from low-power embedded systems to high-performance computing.
Security: The open nature of RISC-V makes it easier to verify the architecture for security vulnerabilities. By allowing independent reviews and audits, it helps build confidence in the design and reduces the risk of hidden backdoors or security flaws.

We published an article where we describe and analyze 5 good things about RISC-V.

Is RISC-V open source?

RISC-V is an open standard that allows companies to create RISC-V microarchitectures. Companies can then license the IP as either open-source or commercial.

Is RISC-V the future?

For the first time in decades, designers have a viable alternative to X86 or Arm in RISC-V. The RISC-V market share is growing and will continue to grow. Semico Research predicts that the market will consume 62.4 billion RISC-V CPU cores by 2025.