Andes Unveils Details of its Entry Level D23 RISC-V Processor Core

January 12, 2023 by Jake Hertz

With the new processor, the company hopes to bring a feature-rich set of functions to the RISC-V community.

At the RISC-V Summit last month, Andes Technology announced its new D23 entry-level RISC-V processor core to the industry. At the time, there was not much truly known about the product, but recently the company followed through with the posting of specifications and technical details of the D23.

Now, with more information made public, we can take a deeper look at the technology and find out more about Andes’ offering. In this article, we’ll take a look at the new processor from Andes to understand what they are contributing to the industry.


AndesCore D23

According to the newly released information, the AndesCore D23 processor is a 32-bit design based around Andes’ AndeStar V5/V5e architecture. True to the idea of an entry-level processor, the D23 consists of a simple 3-stage pipeline, configurable cache from 1 KB up to 32 KB, and only 16 to 32 general-purpose registers available.


D23 block diagram.

D23 block diagram. Image used courtesy of Andes Technology


Despite being an entry-level RISC-V option, the D23 does come with a variety of features and capabilities, including support for the RISC-V RV32GC extension as well as support for recently ratified extensions such as bit manipulation, scalar cryptography, cache management operation, and code size reduction.

In addition, the D23 supports the packed SIMD/DSP extension, which can be paired with the Andes NN SDK, which includes TensorFlow Lite and the Andes AI optimizer. Together, these features hope to provide the D23 with AI acceleration in a small package.


Core-Local Interrupt Controller

Another major feature of the D23 is the Core-Local Interrupt Controller (CLIC), which can service over 1,000 interrupts and includes features such as interrupt prioritization and pre-emption. The core also supports Andes V5 extensions, including StackSafe for hardware stack protection, CoDense for code size compression, and PowerBrake for power management.

Overall, the D23 was designed with a focus on efficiency and low power consumption, making it well suited for a wide range of applications including smart home appliances, wearables, IoT devices, and special-purpose microcontrollers.

The D23 is coming out on the heels of continuing ramp up of success for Andes. During his presentation at the RISC-V Summit last month, Frankwell Lin, Chairman and CEO of Andes Technology, gave some of the history of their RISC-V journey.

“We developed our own proprietary processor microarchitecture technology in 2005 and switched over to the open RISC-V ISA in 2017,” he says. Importantly, Andes engineers developed tool chains that enabled the company to rapidly create RISC-V processor core products. In recent months, the market cap for Andes grew to nearly $1 billion, according to Lin.


What Makes a Processor Core “Entry Level”?

In today’s computing market, there is a lot of jargon and classifications that get thrown around. Between terms like high-performance, low-power, and ultra-low power, figuring out which processor is right for you can often be confusing.

In Andes’ newest release, the D23 core, they are labeling their processor as “entry-level”, but what does this really mean?

This slide from Andes’s RISC-V Summit presentation shows how the company positions its new D23 core.

This slide from Andes’s RISC-V Summit presentation shows how the company positions its new D23 core. Image used courtesy of RISC-V Summit


In Andes’ newest release, the D23 core, they are labeling their processor as “entry-level”, but what does this really mean?

In most cases, when people describe a processor as “entry-level”, they are typically describing a processor that is designed for use in lower-end or less demanding applications. Entry-level processor cores typically have less powerful features and capabilities than more advanced or “high-end cores” but are designed to be more affordable and accessible for a wider range of customers.

Some of the characteristics that are usually considered when defining a processor core as "entry-level" are:

  • Power and Performance: Entry-level processor cores are usually designed for lower power consumption and lower performance requirements, compared to higher-end cores,
  • Complexity: the entry-level cores may have a less complex design, less number of pipeline stages, or less memory cache.
  • Cost: the entry-level cores are usually aimed at budget-constrained designs.

Meanwhile, entry-level processor cores may also have fewer peripheral interfaces, limited functionality, or a smaller instruction set compared to more advanced cores.


Another On-ramp for RISC-V Adoption?

Based on all the activity we’ve seen and covered about RISC-V in 2022, it’s clear that the technology is moving ahead full steam. At the RISC-V Summit, leaders in that community even declared that RISC-V is inevitable. An entry-level 32-bit processor core like the D23 from Andes perhaps only adds strength to that argument.