Why RISC-V Can Be a Game Changer?

In a world dominated by proprietary chip architectures, a quiet shift is underway. RISC-V, an open-source alternative, is redefining how we think about processor design—especially in the VLSI world.

Understanding Architecture in Processor Design

At the heart of any computing system is the Instruction Set Architecture (ISA). This defines the set of operations a processor can perform and how software communicates with the hardware. It’s an essential layer—one that shapes not just how processors work internally, but also how software is written and optimized.

Two of the most dominant ISAs in the current landscape are x86 (used in most desktops and servers) and ARM (widely used in mobile and embedded systems). Both are proprietary: x86 is maintained by Intel and AMD under strict licensing, while ARM is owned by Arm Holdings, which licenses the ISA and IP cores to companies building chips.

This proprietary nature has shaped the semiconductor industry’s development for decades. Companies that want to build processors with these architectures must license them—an approach that can be restrictive in terms of both cost and flexibility, especially for those developing custom silicon solutions or working in academia and research.

The Introduction of RISC-V

RISC-V emerged in 2010 from the University of California, Berkeley, as the fifth iteration of a RISC (Reduced Instruction Set Computing) design project—hence the “V” in the name. It was created as an open and extensible ISA suitable for modern processor designs, intended to be used freely by academia, startups, and industry without the legal or financial constraints that come with traditional ISAs.

Unlike x86 and ARM, RISC-V is open source. The specification is maintained by the RISC-V Foundation (now RISC-V International), and anyone can implement it in silicon without paying royalties or signing restrictive agreements.

This makes RISC-V particularly relevant in the context of VLSI (Very Large Scale Integration) design, where flexibility and cost-efficiency are key. RISC-V’s modularity allows chip designers to start with a small base instruction set and add only the extensions they need, avoiding unnecessary hardware overhead and simplifying verification.

RISC and CISC: Architectural Context

To understand RISC-V’s approach, it helps to compare it with traditional CISC (Complex Instruction Set Computing) and RISC philosophies.

• CISC, exemplified by x86, includes complex instructions that can perform multi-step operations in a single instruction. This can reduce code size but leads to more complex hardware, longer decode stages, and more challenging verification.

• RISC, which underlies both ARM and RISC-V, focuses on simplicity and consistency. Each instruction typically performs a single task and is designed to execute in a uniform number of cycles. This results in simpler hardware, better energy efficiency, and easier pipelining.

RISC-V follows the RISC design principle, but modernizes it with a clean, extensible specification. This is particularly advantageous in current VLSI workflows, where modular design, toolchain compatibility, and post-layout timing closure benefit from simplified and predictable instruction sets.

Why Open Source Architecture Matters

From a VLSI perspective, an open ISA like RISC-V introduces significant benefits:

• Design Freedom: Engineers can develop processors tailored to specific workloads—whether low-power IoT, real-time control, or high-performance computing—without unnecessary instruction logic.

• Lower Cost: There are no licensing fees to use RISC-V, making it suitable for cost-sensitive applications or regions investing in local semiconductor development.

• Transparency and Customization: Because the specification is open, it can be audited, extended, and customized. This is useful for security-focused designs and domain-specific accelerators.

• Toolchain Ecosystem: Compiler support (e.g., GCC, LLVM), simulation tools, verification environments, and EDA workflows are increasingly supporting RISC-V out of the box. This lowers the barrier to entry for VLSI teams.

This is particularly important as custom silicon becomes more prominent. In chiplet-based systems, AI accelerators, and domain-specific SoCs, the ability to adjust the architecture to fit power, area, and performance goals is critical.

Industrial Adoption and Ecosystem Growth

Although RISC-V started in academia, it is now gaining industry traction. Several companies have released or are developing commercial RISC-V processors, targeting a range of applications—from microcontrollers to edge AI and datacenter compute.

The ecosystem around RISC-V has also expanded to include:

• IP vendors offering synthesizable RISC-V cores
• Verification tools with compliance suites and assertion libraries
• Synthesis and P&R support from major EDA tools
• Standard extensions (like vector processing, bit manipulation, and DSP-friendly instructions)

This makes RISC-V viable not just for experimental designs, but also for production-grade chips.

Relevance for VLSI Design Teams

In traditional chip development, ISA constraints often limit how much the architecture can be optimized for silicon. RISC-V offers a different approach: define only what is necessary, customize as needed, and avoid overhead.

In practical terms, this can lead to:

• Reduced logic area, due to the use of minimal instruction sets
• Simplified pipeline design, making it easier to meet timing during backend flow
• Faster verification, as smaller and cleaner ISAs reduce the state space and potential corner cases
• Easier integration with accelerators or specialized coprocessors

For teams building chips under aggressive schedules or for specific application domains (automotive, aerospace, edge computing), this flexibility is a significant advantage.

Looking Ahead

As the industry continues to move beyond general-purpose processors and toward application-specific silicon, ISA flexibility will become increasingly important. Whether it’s to build energy-efficient edge AI processors, secure microcontrollers, or scalable chiplets for cloud systems, having an open, extensible architecture makes a difference.

RISC-V fits well within this evolving VLSI landscape, offering a foundation that is adaptable, license-free, and backed by a growing ecosystem.

It’s not intended to replace all existing architectures overnight, but it provides a strong alternative—especially in environments where customization, openness, and control over the full stack are important.

Conclusion

RISC-V represents a shift in how processor architectures are developed, shared, and implemented. For VLSI engineers, it removes several constraints imposed by proprietary ISAs and opens up new possibilities for silicon-level innovation.

As the semiconductor industry increasingly focuses on specialized hardware and design reuse, RISC-V is positioned to be a practical and strategic tool—especially for teams seeking flexibility and long-term control over their designs.

In that context, RISC-V isn’t just another architecture. It’s a response to the changing demands of modern chip design.