Industrial Electronics

First general-purpose 32-bit RISC-V MCUs with internally developed CPU core

29 March 2024

Advanced semiconductor solutions supplier Renesas Electronics Corporation has announced the industry’s first general-purpose 32-bit RISC-V-based microcontrollers (MCUs) built with an internally developed CPU core. While many MCU providers have recently joined investment alliances to advance the development of RISC-V products, Renesas has already designed and tested a new RISC-V core independently, which is now implemented in a commercial product and available globally. The new R9A02G021 group of MCUs provides embedded systems designers a clear path to developing a wide range of power-conscious, cost-sensitive applications based on the open-source instruction set architecture (ISA).

Source: Renesas Electronics CorporationSource: Renesas Electronics Corporation

While most of today’s RISC-V solutions target specific applications, the R9A02G021 group MCUs are designed to serve multiple end markets, such as internet of things sensors, consumer electronics, medical devices, small appliances and industrial systems. Similar to existing general-purpose MCUs, designers will have access to a full-scale development environment for the R9A02G021, provided by Renesas and its extensive network of toolchain partners. This will allow them to significantly reduce costs, engineering resources and development time.

As an early adopter of RISC-V, Renesas has a rich offering of RISC-V application-specific products, including its 32-bit voice-control and motor-control ASSP devices and RZ/Five 64-bit general purpose microprocessors (MPUs), which were built on CPU cores developed by Andes Technology Corp. The R9A02G021 group represents the first generation of general-purpose MCUs based on the internally developed RISC-V core by Renesas that will roll out over the next several years.

Balancing performance and power

The R9A02G021 RISC-V group offers ample performance with clock speeds up to 48 MHz, while consuming extremely low power in standby at 0.3 µA. It provides 128 KB of fast flash memory, 16 KB of SRAM memory and 4 KB of flash memory for data storage. Designed to withstand harsh conditions, the MCUs can operate reliably at ambient temperatures ranging from -40° C to 125° C. The MCUs come with standard serial communications interfaces, as well as digital-to-analog converter (DAC) and analog-to-digital converter (ADC) functions to facilitate high-speed and secure connections with sensors, displays and other external modules. The wide 1.6 V to 5.5 V input voltage range enables low-voltage, low-current operation and allows noise immunity, making the R9A02G021 ideal for battery-powered devices.

Key features of the R9A02G021 MCU group

  • CPU: RISC-V core at 48 MHz, 3.27 Coremark/MHz
  • Memory: 128 KB code flash, 16 KB SRAM (12 KB and ECC SRAM 4KB) and 4 KB data flash
  • Power Consumption: 162 µA/MHz (Active power), 0.3 µA (SW Standby), 4 µs (Standby wakeup)
  • Serial communications interfaces: UART, SPI, I2C, SAU
  • Analog peripherals: 12-bit ADC and 8-bit DAC
  • Temperature range: -40° C to 125° C (Ta)
  • Operating voltage range: 1.6 V to 5.5 V
  • Packages: 16 WLCSP, 24/32/48 QFN package (QFP option)

The R9A02G021 RISC-V MCUs are fully supported by Renesas’ e² studio Integrated Development Environment (IDE), offered to customers at no cost. The comprehensive toolchain includes a code configurator, the LLVM compiler and a fast prototyping board (FPB). Complete development environments are also available from Renesas’ partners: IAR with its Embedded Workbench IDE and I-jet debug probe, and SEGGER with the Embedded Studio IDE, J-Link debug probes and Flasher production programmers. Supporting documentation includes the FPB user manual, a Getting Started guide, schematics, Bill of Materials (BOM) and Gerber files.

Winning combinations

Renesas has developed “All-in-One Smart Pressure Cooking Pot,” which combines the R9A02G021 with numerous compatible products from its portfolio, like RAA211412 DC/DC converter, ZSSC3224/3240 signal conditioners, RV1S9231A IGBT driver, RJH60T04DPQ IGBT and DA16200 Wi-Fi system-on-chip. Combined, they enable a cost-efficient, compact, modular solution for modern connected appliances. These winning combinations are technically vetted system architectures from mutually compatible devices that work together seamlessly to bring an optimized, low-risk design for faster time to market.


The R9A02G021 RISC-V MCU is available today through global distributors, along with the FPB, software and development tools. More information is available at the Renesas website.

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