Chipmakers, Researchers, and Hobbyists Show Off the Many Faces of RISC-V

September 23, 2023 by Abdulwaliy Oyekunle

In this roundup, we review the ways RISC-V is making its mark in the computing world—from small-scale gaming projects to large-scale corporate initiatives.

While the royalty-free RISC-V instruction set architecture (ISA) has always been popular among individual designers and hobbyists, more big-name chipmakers and researchers are taking advantage of the custom processors for wireless 5G, IoT, and automotive applications.

This summer, a consortium of semiconductor manufacturers, including Infineon, Qualcomm, and NXP, joined together to commercialize products based on the open-source RISC-V architecture. Just prior to this announcement, a group of Chinese researchers pushed the limits of AI by designing an algorithm that built a RISC-V computer in under five hours.


PCB design of an AI-designed RISC-V CPU

PCB design of an AI-designed RISC-V CPU. Image used courtesy of arXiv


And this group wasn't alone in building a RISC-V computer in a digital landscape. Terraria player Xander Naumenko recently built a fully-compliant RISC-V computer in the 2D adventure game—and then played Pong on it. 

This article discusses each of these varied use cases of RISC-V to illustrate the strides and manifold applications of the ever-flexible ISA.


Renowned Chipmakers Jointly Push RISC-V Adoption

Infineon, Qualcomm, NXP, Bosch, and Nordic Semiconductor recently joined together to invest in a company that will push global RISC-V adoption. The group intends to do this by jointly commercializing state-of-the-art reference designs based on RISC-V and encouraging other industry leaders and governments to support the initiative. The five companies propose their new entity to be based in Germany.

Key players in the industry have committed to expanding the RISC-V ecosystem

Key players in the industry have committed to expanding the RISC-V ecosystem. Image used courtesy of Nordic Semiconductor

With two of the leading companies, NXP and Infineon, specializing in automotive applications, the collaboration will first focus on RISC-V-based vehicle dashboard products. The group has stated plans to later expand to mobile and IoT use cases. 


AI Designs RISC-V Computer 

Engineers traditionally develop CPUs using EDA tools like Verilog to write hardware description languages (HDL)—a process that can take several months. To bypass this process, a group of researchers from several institutions, including the University of Chinese Academy of Sciences and the University of Science and Technology of China, created a system that learns informal input-output (IO) examples of a CPU and realizes a circuit logic in the form of a large-scale Boolean function.

The researchers implemented a binary speculation diagram (BSD) in lieu of the conventional binary decision diagram (BDD) to represent the large-scale Boolean functions. While manually-created CPU designs take approximately 5,000 hours to complete, the AI-designed CPU was trained and designed in under five hours. To ascertain the accuracy of the new CPU, the team employed a Monte Carlo-based policy to expand the realized BSD, which revealed a 99.9% accuracy. 

On the Dhrystone benchmark, the AI-designed CPU outperforms some manually-designed CPUs

On the Dhrystone benchmark, the AI-designed CPU outperforms some manually-designed CPUs. Image used courtesy of arXiv

The CPU was fabricated using scripts on 65nm technology and demonstrated a clock speed of 300 MHZ. During the evaluation, the researchers reported that the AI-designed CPU performed comparably to Intel's i486SX, a microprocessor built in 1991, and doesn't perform well compared to modern processors like the Intel Core i7 3930K.


Building a RISC-V Computer in Terraria

Xander Naumenko at the From Scratch YouTube channel recently showed off how he built a 32-bit RISC-V computer within Terraria, the 2D adventure game, and played Pong on it. Naumenko described his experiment as a "computer running a game running a computer running a game." 

Developed over five months and over 600 hours, the "Computerraria project" required Naumenko to use expansive numbers of in-game logic gates—a task that required him to redesign the game's circuits to fit a new paradigm within the game. Naumenko reported that the resulting RISC-V computer within Terraria featured the rv32i instruction set and offered a clock speed of ~5kHz and 96 kb RAM.



Naumenko concluded his project by playing the game Pong on the newly-built 32-bit computer within Terraria. In addition to the walkthrough video above, Naumenko has made his project open source on GitHub



In your experience, how have you seen RISC-V transforming the computing landscape? Share your thoughts in the comments below.