SiFive Essential 6-Series, 21G3 Release Add Mid-Range Performance & Features to Leading RISC-V IP Portfolio

By Brandon Lewis


Embedded Computing Design

December 10, 2021


SiFive Essential 6-Series, 21G3 Release Add Mid-Range Performance & Features to Leading RISC-V IP Portfolio

SiFive announced the Essential 6-Series of real-time and mid-range application processors ahead of this week’s RISC-V Summit. The company also made its 21G3 release available, which includes a series of updates to their processor IP portfolio.

The SiFive Essential 6-Series is a family of eight-stage, single-issue pipline IP that includes the single- or quad-core 64-bit U6 and S6 processors, as well as the single- or quad-core 32-bit E6 deeply embedded microcontroller. The U6 is a Linux-capable processor, while the others target real-time uses.

Despite their name, the 6-Series processors rely on the SiFive Essential 7-Series architecture. They come pre-configured but are tunable for general-purpose embedded/industrial and IoT, real-time embedded, or automotive applications.

“The new SiFive Essential 6-Series focuses our offerings for mid-range performance,” says Chris Jones, VP of Products at SiFive.

TIRIAS Research’ Principal Analyst Steve Leibson states that “6-Series processor cores expands the company’s 'Essential' family of processor cores and creates an even more comprehensive offering of application-tuned, 64- and 32-bit RISC-V processor cores, starting with high-end, multi-core application processors and extending all the way down to individual, low-power, embedded microcontrollers, which can all be customized to cover an even broader design spectrum.”

21G3 Portfolio-Wide Release Highlights

Meanwhile, the 21G3 release improves clock gating and power management across the entire SiFive portfolio. Another significant part of the release focuses on recently ratified RISC-V extensions, including the addition of Hypervisor extensions to SiFive Performance IP and SiFive Intelligence Extensions, which adds RISC-V Vector (RVV) extensions to IPs like the Intelligence X280.

SiFive Intelligence Extensions now supports the following AI/ML-centric features:

  • BFLOAT16 Compute
  • Quantization Acceleration
  • Improved Multi-Cluster

Finally, release 21G3 introduces SiFive Shield WorldGuard for the Essential line, which is a comparable technology to Arm’s TrustZone.

More information on all of the solutions outlined here can be found at

Brandon is responsible for guiding content strategy, editorial direction, and community engagement across the Embedded Computing Design ecosystem. A 10-year veteran of the electronics media industry, he enjoys covering topics ranging from development kits to cybersecurity and tech business models. Brandon received a BA in English Literature from Arizona State University, where he graduated cum laude. He can be reached at [email protected].

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