The RL78/G23 microcontroller group is a new generation of the RL78 family of microcontrollers, with 41μA/MHz CPU operation. The RL78/G23 group has the industry’s lowest power consumption with 210nA at stop (4KB SRAM retention), and a snooze mode sequencer which significantly reduces power consumption during intermittent operation. The RL78/G23 group features a wide operating voltage range of 1.6V to 5.5V at up to 32MHz, a broad range of package pin counts from 30 pins to 128 pins, and up to 768KB of flash memory. In addition to enhanced analog and security features, it also incorporates logic and event link controllers (ELCL) and the first capacitive touch sensing unit (CTSU2L) in the RL78 family. A rich development environment is also provided for the RL78/G23, including a fast prototyping board. This board allows users to write and debug programs with an easy-to-use GUI, by simply connecting a USB cable and a smart configurator without any additional tools required. The RL78/G23 is compatible with the existing RL78 family and can be a seamless replacement, making it suitable for a wide range of applications, from home appliance and consumer electronics to industrial equipment.


  • CPU: RL78 core, Max. 32MHz
  • Up to 768kB Flash Memory and 48kB SRAM
  • Memory: SRAM up to. 48KB, Program Flash up to 768KB
  • 8KB Data Flash to store data as in EEPROM
  • Scalable from 30-pin to 128-pin packages
  • Wide operating voltage range of 1.6V to 5.5V
  • Enhanced Capacitive Sensing Unit (CTSU2L)
  • Timer: 16-bit Timer (ch) x 16, 8-bit Timer, Watchdog Timer (ch) x 1,32-bit Interval Timer x 1 ch
  • PWM: PWM Output x 14
  • Analog function: 12-bit A/D Converter (ch) x 26, 8-bit D/A - Converter (ch) x 2, Comparator x 2
  • On-chip Oscillator Freq. (MHz): High-Speed: up to 32MHz
  • Middle-Speed: up to 4MHz
  • Low-speed: 32.768kHz
  • Snooze mode sequencer
  • Logic & Event link controller
  • Others: RTC, Power-On Reset, Low Voltage Detection
  • A large selection of packages (LQFP, QFN, LGA, BGA, WLCSP)




  • General Purpose
  • Consumer applications
  • Home Appliance
  • Industrial Automation
  • Building Automation


Design & Development

Software & Tools

Software & Tools

Software title
Software type
RI78V4 V2 Real-time OS for RL78 Family
μITRON Specification real-time OS for RL78 Family [Required IDE : CS+]
ITRON OS Renesas
RL78 Web Simulator
Right online tools to support initial evaluation of the low power consumption RL78 Family. Lineup: MCU Simulator Online and Current Consumption Calculator. Free of charge.
Simulator Renesas
C Compiler Package for RL78 Family [CC-RL]
C Compiler Package for RL78 Family [IDE: CS+, e² studio]
Compiler/Assembler Renesas
QE for Current Consumption: A Dedicated Tool for Current Measurement
Development assistance tool helps to shorten the times taken in operations for the tuning of currents drawn. [Standard item in the "e² studio" and CS+ (CS+ for CC only) IDEs] [Support MCU/MPU: RX, RL78]
Solution Toolkit Renesas
QE for Capacitive Touch: Development Assistance Tool for Capacitive Touch Sensors
In developing embedded system using the capacitive touch sensor of MCUs, you can easily setup initial configurations of the touch interface as well as process the tuning of sensors, and reduce development time. [Plugin for Renesas IDE "e2 studio"] [Standalone Version] [Support MCU/MPU:RA, RL78, RX, Renesas Synergy™]
Solution Toolkit Renesas
E2 emulator [RTE0T00020KCE00000R]
On-chip debugging emulator. Also available as a flash memory programmer. [Support MCU/MPU: RA, RE, RH850, R-Car D1, RL78, RX]
Emulator Renesas
E2 emulator Lite [RTE0T0002LKCE00000R]
On-chip debugging emulator. Also available as a flash memory programmer. [Support MCU/MPU: RA, RE, RL78, RX]
Emulator Renesas
Renesas integrated development environment (IDE) [Support MCU/MPU: RH850, V850, RX, RL78, 78K0R, 78K0] (Note: CS+ is not generally promoted to U.S. and European customers.) (Note: To use Smart Configurator on CS+ for RL78/G23 and RX family MCUs, install the Smart Configurator for each MCU family separately downloading from ”Design & Support” > ”Development Tools” > ”Smart Configurator”)
IDE and Coding Tool Renesas
CS+ Partner OS Aware Debugging Plug-in
Features for task level debugging of real-time OS applications [Plugin for Renesas IDE CS+] [Support MCU/MPU: RX, RL78]
Plug-in, OS Aware Debugging, Etc. Renesas
Flash memory programmer [Programming software: Dedicated GUI-based software, the "FP6 Terminal"] [Support MCU/MPU and devices: RA, RE, RX, RL78, RH850, Renesas Synergy, Power Management, Renesas USB Power Delivery Family, ICs for Motor Driver/Actuator Driver, SuperH RISC engine, V850, 78K, R8C]
Programmer (Unit/SW) Renesas
Simulator for e² studio of RL78 Family
Simulator for RL78 Family [Support IDE: e² studio] (Note: This product is included in the Renesas IDE "e² studio" and is not available separately.)
Simulator Renesas
Renesas Flash Programmer (Programming GUI)
Flash memory programming software [Support MCU/MPU and devices: RA, RE, RX, RL78, RH850, Renesas Synergy, Power Management, Renesas USB Power Delivery Family, ICs for Motor Driver/Actuator Driver, V850, 78KR, 78K0]
Programmer (Unit/SW) Renesas
Code Flash Libraries (Flash Self Programming Libraries)
Libraries for the reprogramming of code area flash memory, including EEPROM emulation libraries for the code areas of 78K-family products
Self Programming Library (Flash Library) Renesas
Data Flash Libraries
Libraries for the reprogramming of data flash memory, including EEPROM emulation libraries for the data areas of RL78-family products
Self Programming Library (Flash Library) Renesas
Sensor Software Modules for Renesas MCU Platforms
Middleware (FIT module and FSP module) and sample software packages that enable control and data acquisition for Renesas sensor products.
Sensor Renesas
Crypto Library
Robust encode library to ensure security for all types of system developments
Security / Crypto Renesas
RL78 Smart Configurator
RL78 Smart Configurator is a utility for combining software in ways that meet your needs. It simplifies the embedding of Renesas drivers in your systems through supports for importing middleware and drivers and configuring pins.
Solution Toolkit Renesas
Sound Playback/Compression System [M3S-S2-Tiny] for RL78 Family
Sound playback system for RL78 Family
Sound / Voice Renesas
e² studio - information for RL78 Family
Eclipse-based Renesas integrated development environment (IDE).
IDE and Coding Tool Renesas
DALI Master Controller GUI
The DALI Master Controller GUI controls an RL78/I1A lighting communication master evaluation board
Code Generator Renesas
FAT File System [M3S-TFAT-Tiny] for the RL78 Family
FAT file system for RL78 Family
File System Renesas
SPI/QSPI Serial Flash Memory, QSPI Serial Phase Change Memory Driver
Device Driver for SPI and QSPI Serial Flash Memory and QSPI Serial Phase Change Memory
Serial Memory Renesas
IAR Embedded Workbench for Renesas RL78
IAR Embedded Workbench provides extensive support for RL78 devices. IAR Embedded Workbench is a complete set of development tools with leading optimization technology for creating powerful automotive applications.
IDE and Coding Tool IAR Systems
Renesas IAR Embedded Workbench Device-Support-Packages
Renesas IAR Embedded Workbench Device-Support-Packages include all device-specific files to be used with the Embedded Workbench IDE.
IDE and Coding Tool Renesas
QE for OTA: Development Assistance for Cloud
QE for OTA is a development assistance tool that enables easy trial of over-the-air (OTA) firmware updates using cloud services. [Plugin for Renesas IDE "e² studio"] [Support MCU/MPU: RX, RL78] [Support clouds service: Amazon Web Services (AWS), Microsoft Azure]
Solution Toolkit Renesas
25 items

Software Downloads

Type Title Date
PCB Design Files PDF 109 KB
PCB Design Files Log in to Download ZIP 4.24 MB
PCB Design Files PDF 240 KB
3 items

Sample Code

Boards & Kits

Boards & Kits


AI Coding with Chat-GPT for RL78 Microcontroller (Arduino)

This video introduces how to do AI coding using ChatGPT and the RL78 Arduino-compatible board, including practical examples such as lighting up a 7Seg LED, rotating a motor, and sensing with a temperature and humidity sensor. Even beginners can easily experience AI coding!

Detailed step-by-step instructions:

AI Coding with Chat-GPT for RL78 Microcontroller (Arduino) | Renesas


Related products: RL78/G23-64p FPB

Related sources: Quick Start Guide page (GitHub)



1. Informational Purposes Only: This video serves as a general guide to using ChatGPT/GPT-4 to write code for an Arduino RL78 evaluation board. Renesas does not guarantee the accuracy or completeness of the content provided.

2. Third-Party Rights Infringement: Note that code generated using ChatGPT/GPT-4 might potentially infringe third-party intellectual property rights. Renesas makes no representations or warranties that the use of ChatGPT/GPT-4 will not violate any third-party rights. Users are urged to exercise due diligence to ensure compliance with applicable laws and third-party rights.

3. No Liability: In no event shall Renesas be liable for any damages, data loss, or other adverse consequences that may occur as a result of using the information, code, techniques, or tools demonstrated in this video. You may want to apply industry standard static and dynamic code assessments as AI code has been recognized to possibly contain malware fragments as well as deriving other unwanted outcomes.