RISC-V Celebrates 10 Years of Open-Source ISA

August 25, 2020 by Jake Hertz

On the heels of RISC-V’s 10th birthday, let's explore the history of RISC-V from its inception to today.

A pioneer in open-standard instruction set architecture (ISA) design, RISC-V has been a valuable asset to engineers for more than 10 years. Starting with its humble beginnings at UC Berkeley, the project blew up in an unanticipated way and has since become a staple in the industry.


RISC-V recently celebrated its 10-year anniversary at UC Berkeley

RISC-V recently celebrated its 10-year anniversary at UC Berkeley, where researchers are continually improving the open-source standard. Image used courtesy of the RISC-V Foundation

Let’s take a look at the history of RISC-V so we can understand how it grew to be as big as it is today.


How RISC-V Fills a CPU Knowledge Gap

Designing a CPU requires skills in fields such as digital logic design, operating systems, silicon layout, verification, and others. Needless to say, successfully designing a CPU requires an eclectic group of talents and knowledge.

For this reason, companies like MIPS Technologies and Arm Holdings will license their patents and design methodologies to other CPU designers. But while these prepackaged offerings are the more practical option, this expertise comes with a lofty price tag. Additionally, designers often never understand the design of this specialized IP.


Microsemi's programmable RISC-V solution

Microsemi's programmable RISC-V solution. Image used courtesy of Microsemi

These challenges gave rise to RISC-V. In the summer of 2010, Krste Asanović, with the aid of David Patterson, Yunsup Lee, and Andrew Waterman, looked to open-source computer systems and started the RISC-V project.


From a Single Paper to a Linux Team-Up

RISC-V is not processor core, but a free, open-source instruction set architecture based on a reduced instruction set computing (RISC) principles. As a fixed ISA specification, designers can build their own implementation.

The first milestone in the timeline of RISC-V was the publication of the project's first paper, "The RISC-V Instruction Set Manual, Volume 1: Base User-Level ISA" in May 2011. That same year yielded another huge milestone: the first tape-out of a RISC-V chip. The chip, at 28nm FDSOI, was donated by STMicroelectronics and served as a proof of concept for the project.

As the standard grew more popular, the original owners wanted to establish a foundation to maintain RISC-V. The RISC-V Foundation was formed in 2015 with 36 founding members.


Timeline of RISC-V

Timeline of RISC-V development given at the RISC-V Foundation's "State of the Union" address in 2019. Image used courtesy of the RISC-V Foundation

As explained on the foundation’s website, the goal of the RISC-V Foundation is to “build an open, collaborative community of software and hardware innovators based on the RISC-V ISA." As a non-profit corporation, the RISC-V Foundation is governed by its members, who seek to push the adoption of the RISC-V ISA. 

Three years after the RISC-V Foundation's establishment, RISC-V continued growing in popularity. In 2018, the Foundation announced a joint collaboration with the Linux Foundation. The move was hugely important for RISC-V, since the Linux Foundation, based on its successful and longstanding history, provided operational, technical, and strategic support for RISC-V.

This, in turn, only led to greater development and adoption of the standard.


RISC-V International Association

In March of this year, the RISC-V International Association was established in Switzerland.


RISC-V Foundation membership growth

RISC-V Foundation membership growth. Image used courtesy of Business Wire

The foundation shifted to a new, more inclusive membership structure by which members of RISC-V International participate in the development of the RISC-V ISA specification and extensions as well as related hardware and software.


What Makes RISC-V So Successful?

Providing designers an open-source standard to develop CPUs has proven to be a wildly successful experiment. The RISC-V website states the following:

“The worldwide interest in RISC-V is not because it is a great new chip technology; the interest is because it is a common free and open standard to which software can be ported, and which allows anyone to freely develop their own hardware to run the software. RISC-V International does not manage or make available any open-source RISC-V implementations, only the standard specifications.”

The historical and continued growth of RISC-V shows the value of open-source design and has led to significant developments in the industry. Now over 10 years old, RISC-V shows no signs of slowing down anytime soon.