Exploring Advanced Power Optimization for a More Sustainable Future

William Ruby

Oct 06, 2023 / 3 min read

Over the years, the methodology for low-power design in system-on-chip (SoC) architectures has undergone a significant evolution. What started as rudimentary techniques for conserving power, such as clock gating and voltage scaling, has matured into a complex ecosystem of strategies and tools designed to optimize energy efficiency at every level. Advances in technology have introduced new paradigms like dynamic voltage and frequency scaling (DVFS), power domains, and advanced sleep modes. Meanwhile, the rise of loT devices, mobile computing, automotive systems, and data centers has put increasing pressure on chip designers to prioritize power efficiency without sacrificing performance. This journey reflects not just technological progress, but a broader understanding of how integral power optimization is to the success of SoC designs in today’s interconnected and energy-conscious world.

Nowadays, there are more opportunities to reduce power and to make your chip design more energy efficient at higher levels of abstraction. The field of SoC low-power methodology is at an advanced stage, incorporating multi-disciplinary approaches that range from circuit-level optimization to system-level power management techniques. In addition, the use of machine learning algorithms for predictive power management, real-time power profiling tools, and comprehensive simulation platforms are becoming standard practices. The growing integration of hardware accelerators specialized for low-power operation also marks a significant leap. These advancements are driven by the urgent need for energy efficiency across various sectors. Let’s explore how we got here, the major challenge, and solutions to achieve the best power, performance, and area (PPA) for your chip designs.

what is power optimization

The Evolution of Low-Power Design Techniques

The Starting Point

In the early days, the semiconductor industry relied heavily on SPICE, a circuit simulator, to evaluate power consumption at the transistor level. Given its limited capacity and speed, SPICE was far from perfect but was the best available tool of the era. From being a catch-all circuit simulator, SPICE eventually evolved into an enabler of library characterization for power and, therefore, highly accurate gate-level power analysis.

The Middle Ages

The move from SPICE to gate-level tools marked a significant shift. These tools, relying on libraries characterized for power, introduced a new level of abstraction. This trend continued with the evolution towards register-transfer level (RTL) tools, system-level approaches, and now into the realm of emulation power profiling. Interestingly, this tool development path contrasts with the aforementioned elements. At higher levels of abstraction, there are more opportunities for power reduction, although with less accuracy. As we dive deeper into design stages (e.g., RTL, implementation), the analysis accuracy improves, but design flexibility shrinks.

The Modern Era

Today, the focus is increasingly on achieving accuracy at the RTL and higher abstraction levels. Emulation, for instance, provides a more realistic assessment of power profiles by using real workloads rather than synthetic vectors. It considers the real-world activity of designs, offering a practical perspective on power consumption over billions of clock cycles.

The Road Ahead

The future of low-power design lies in achieving greater accuracy at higher abstraction levels. This involves developing higher level models for IP blocks, processor cores, hardware accelerators, etc. To this end, the industry is actively working on creating model structures, understanding power consumption dependencies, and finding ways to handle vast amounts of workload data.

Despite these advances, the challenge remains: How can we ensure maximum accuracy across all design stages? The answer lies in constantly refining tools and methodologies, ensuring they align with the evolving needs of power-efficient designs.

Designing the Future with Energy-Efficient SoCs

Synopsys offers software-driven low-power exploration, analysis, and optimization across the chip design cycle. The solution is built around industry-leading products for each stage of the design flow, from architecture exploration to power emulation, initial RTL development stages and as the RTL matures, RTL-to-GDSII implementation, automatic test pattern generation, and power signoff.

Low-power design methodology has come a long way, moving from rudimentary tools to sophisticated emulation solutions. With increasing demand for energy-efficient designs shaping a more sustainable future, this journey is bound to continue, pushing the boundaries of innovation in the semiconductor world.

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