Embracing Multicore and RISC-V Architectures in SoC Design

What you’ll learn:

• Discover the advantages of the open-source RISC-V architecture in promoting efficiency and innovation in semiconductor design.
• Learn how RISC-V facilitates the development of multicore SoC designs that meet the growing demands for diverse technological applications.
• Understand the impact of RISC-V on fostering a competitive and collaborative ecosystem in the semiconductor industry. 

The rise of the RISC-V Instruction Set Architecture (ISA), managed by RISC-V International, is happening at an exciting time in the evolution of the semiconductor industry. The creation of new technologies is fueling advances across various sectors, including artificial intelligence, the Internet of Things, the automotive industry, and even space exploration.

These innovative product designs are arriving in the same time frame as a new ISA is gaining traction with SoC designers (Fig. 1). In this convergent moment, the RISC-V ISA stands out by offering designers a broader choice of CPU, NPU, and IP core options for their new product designs in the evolving landscape of today's technological explosion.

What is RISC-V?

RISC-V is an open-source ISA that represents a significant shift in the design and development of microprocessors and SoCs. RISC-V is freely available for any individual or company to obtain, modify, and distribute, making it an attractive option. 

Its design philosophy emphasizes simplicity and efficiency, using a reduced set of instructions that can be executed more quickly and consume less power. This openness and flexibility spur innovation and collaboration, as companies and developers can build customizable processors tailored to their specific needs without the licensing fees and restrictions associated with proprietary ISAs.

Until recently, as the primary ISA provider, Arm's business model was to control access. This created a closed environment, enabling the company to become a dominant force in the semiconductor industry. This control also lets Arm generate revenue through licensing fees from manufacturers using its technology while safeguarding its proprietary designs and innovations from unauthorized use or modification.

RISC-V Open Model Advantages

Today, the multicore SoC design landscape has migrated from homogeneous to heterogeneous with multiple ISAs appearing on any given chip. It’s presented an opportunity for designers to consider and evaluate competing ISAs and suppliers. In this environment, CPU cores now perform a range of tasks, which doesn’t necessitate that these cores all come from the same IP vendor. 

Figure 2 shows RISC-V cores delivering a range of tasks in contemporary SoCs, with programmable replacements to deeply embedded finite state machines being the largest use case today. These are followed by the MCU and co-processor functions. 

Interestingly, the function of “Apps Processor” is gaining popularity as more powerful and higher-performing RISC-V CPU cores are being introduced into the market by IP vendors. This indicates a high degree of ongoing innovation happening in the market in response to increasing market demands for more functionality. Competition between RISC-V CPU IP vendors is intense and breeds innovation. 

In contrast to proprietary architectures, the RISC-V ISA is openly available, with the RISC-V standard being evolved and managed by RISC-V International. Collaboration through the multi-company RISC-V member committees has created extensions to the core ISA that can then be customized according to vendor and market needs. 

As a result, specialized domain-specific solutions that meet the precise needs of different applications can be developed more rapidly. This flexibility is in line with the heightening demand for custom-tailored silicon solutions that address specific functional requirements, enhancing performance and efficiency in targeted use cases.

The open model of RISC-V marks a significant shift in the industry, enabling companies for the first time to adopt an ISA without being restricted to any single vendor. Even software developed in accordance with the RISC-V standard can be executed on devices from diverse manufacturers. Such interoperability fosters a competitive environment and stimulates innovation while also mitigating risks and lowering expenses for companies. 

Multi-Company Support for the Flexible RISC-V ISA

Flexibility makes RISC-V an increasingly attractive option for developing and deploying silicon solutions across multiple performance ranges. In the RISC-V domain, multiple CPU IP vendors are part of a community whereby numerous companies are designing new solutions simultaneously. 

In addition, RISC-V International, with over 80 active committees, continues to focus on enhancing the ISA by enabling a multi-company process for evolving the ISA in a standard fashion. This collective effort results in a rapid evolution of the ISA—and a diversity of products that implement it—leading to quicker improvements in performance and increased choices for customers. 

Support for the unified RISC-V ecosystem is growing and has fleshed out nicely, with multiple companies now providing solutions. It encompasses a wide range of technologies and components, supporting everything from hardware design to software development. 

For example, more of the building blocks SoC designers need for their design efforts are now in place and from multiple sources. Moreover, should a team require support in a particular area of their design effort, it’s now likely to be there. As a result, it’s strengthened the design community's confidence in RISC-V technology. 

More Choices for the Semiconductor Design Community

It’s a great time to be in the semiconductor industry as increasing innovation fosters newer and more powerful applications and silicon solutions. RISC-V is driving a new era by providing more design choices, encouraging competition, and facilitating ISA evolution. 

The areas outlined above show the growing relevance of the RISC-V ISA to the semiconductor design community and the overall market. This environment ensures that SoC designers have the freedom to choose from a broad range of solutions, enabling the construction of more advanced systems. 

SHD Group’s research paper, “RISC-V Market Report: Application Forecasts in a Heterogeneous World,” analyzes where the opportunities for RISC-V usage are today and in the future by functionality, device type, product category, and even process geometry. The report focuses on the fact that SoC designs today are no longer homogeneous. Instead, designs now favor the use of multiple architectures delivering different functionalities and from numerous IP vendors all resident on the same silicon—a heterogeneous world.