IP startup Movellus aims to bring droop mitigation technology to the ever-larger microprocessors (CPUs), AI engines (NPUs), switch chips, and other SoCs coming to dominate data-center systems. The recently released Aeonic Generate AWM3 expands the company’s clock-generation line, promising a 50% speedup in droop response compared with the previous AWM2. It responds to transient on-die voltage fluctuations (droops) within 1–2 clock cycles. In combination with the company’s Aeonic Insight Droop Detector, Movellus claims that it offers the industry’s only complete system for droop detection and response that also supplies data for analysis by silicon-analytics software.
Notables
- Applications—voltage droop is an increasing problem as chip sizes scale to reticle limits and beyond. Many transistors switching simultaneously can sink so much current that a chip’s power-rail voltage decreases, increasing transition time and necessitating a longer clock period to avoid prematurely latching signals. Movellus is likely targeting the new batch of behemoth processors that will run large-language models. Because they’re typically smaller designs, embedded processors will benefit less from an integrated droop solution.
- Total adaptation time is the key metric in responding to different droop profiles and severities. A few too many nanoseconds to detect and respond to droop can translate into timing failures. To avoid droop, designers raise voltage margin, increasing power. Movellus claims the fastest total adaptation times in the industry to help designers mitigate transient voltage fluctuations, thereby reducing the nominal operating voltage and power.
- Observability—in addition to droop detection and response, the Movellus system (detector plus AWM3 adaptive clock) provides design teams with advanced telemetry to characterize clock health and droop profiles. SoC teams can use the telemetry data with third-party silicon-lifecycle analytics (e.g., Synopsys SLM and Siemens Tessent) or read out the data through standardized interfaces.
Competition
- In-house technology is always an alternative to a licensed design but can yield unforeseen pitfalls. Bespoke solutions can yield power, performance, and area advantages when tailored to a specific SoC design but offer limited reusability. They’re also difficult to develop because any test chip will differ from the actual SoC.
- Overdesigning is the most common alternative. Many companies have designed large chips without dynamic droop mitigation by requiring additional voltage regulators, integrating on-chip capacitors, and spending more time optimizing the power-delivery network’s layout. They may also raise a nominal voltage, reduce clock rates when activating certain functions, or rewrite software to avoid simultaneously executing power-hungry routines on multiple function units. Although these static approaches compensate for droop, they can increase system power, decrease long-term reliability, or reduce performance.
Customers
Clocking and power are essential to any digital VLSI design but are easily ignored because heretofore haven’t been especially susceptible to problems. Movellus, therefore, must educate chip designers about droop and its consequences. In the meantime, the company’s technical track record and growing customer roster—which includes large, established companies—are beginning to quell nay-sayers. Existing customers will find AWM3 to be a significant upgrade. Once educated about droop, other chipmakers will find it easier to deploy than a homegrown solution and more effective than simplistically adding voltage guard bands and overdesigning chips’ power networks.
Bottom Line
The era of easily achieving generational performance gains through logic design and reaping the benefits of Dennard scaling is long gone. Gains are now harder fought. No fraction of a nanosecond can be casually spared just to be safe, but reticle-busting chips and sub-one-volt rails demand even greater clock and power margins when using traditional techniques. The solution is to dynamically manage droop employing a closed-loop system. For many companies, licensing the technology from Movellus gets them a better product at less long-term cost than designing the equivalent in house. The Movellus value proposition will increase as it continually upgrades elements in its system and adds new functions.
Movellus provided nonpecuniary compensation to sponsor this post.