Renesas Strengthens RL78 Family of Low-Power MCUs with 16-Bit General-Purpose RL78/G23

By Tiera Oliver

Associate Editor

Embedded Computing Design

April 19, 2021


Renesas Strengthens RL78 Family of Low-Power MCUs with 16-Bit General-Purpose RL78/G23

Renesas Electronics announced the launch and mass production of its 16-bit general-purpose RL78/G23 microcontroller (MCU).

Compatible with Renesas' current general-purpose RL78 MCUs, such as the RL78/G13, the RL78/G23 increased the on-chip flash memory capacity to 768 KB. Also, the RL78/G23 expanded on-chip peripheral functions, which extend functionality while reducing the bill of materials (BOM) cost and improving power consumption required by battery powered applications. With this feature combination, the new RL78/G23 is well suited for a range of applications that require both power and cost efficiency, including IoT endpoint devices such as home electronics, remote controls, and sensors.

By adopting a new process, the RL78/G23 realizes 44µA/MHz at CPU operation and 210nA during STOP (with 4KB of SRAM retention), an even lower power consumption compared to current RL78 MCUs. In addition, the newly implemented SNOOZE mode sequencer (SMS) makes it unnecessary to activate the CPU while any peripheral operations are operating in snooze mode, reducing power consumption for applications that utilize intermittent operation. Furthermore, the logic and event link controller (ELCL) add logic functionality to the capabilities of a conventional event link controller (ELC) (Note 1). This makes it possible to create conditional links to multiple events while continuing to benefit from the reduced power consumption realized by the ELC.

The RL78/G23 features a Renesas-exclusive capacitive touch sensor unit that combines high-sensitivity and low-noise characteristics and can be used to implement a contactless gesture-based user interface (UI). The MCU also incorporates security functions that make it possible to develop secure systems. These include a true random number generator (TRNG) for certificate encryption as well as a device-specific unique ID and a customer ID that can be specified by the user. Renesas also provides the RL78/G14 evaluation board, which is already qualified to work with FreeRTOS on Amazon Web Services (AWS) and is listed in the AWS Partner Device Catalog. The RL78/G23 evaluation board is also scheduled to receive FreeRTOS qualification. 

Key features of the RL78/G23 

  • RL78 CPU core running at 32 MHz 
  • Support for operating voltages ranging from 1.6 V to 5.5 V
  • Max. 768 KB of code flash memory, 8 KB of data flash memory, max. 48 KB of SRAM, to support software updates, etc.
  • On-chip capacitive touch sensor unit that can be used to implement a high-sensitivity contactless UI
  • High-precision (±1.0%), high-speed on-chip oscillator
  • Analog functions such as 12-bit A/D converter, 8-bit D/A converter, and temperature sensor, etc.
  • Remote control signal reception function, enabling one-chip implementation of a remote control receiver
  • Output current control (15 mA) port for LED drive and 40 mA output port
  • Package lineup with pin counts from 30 to 128 pins

The RL78/G23 is available now with a reference price of US$1.16 per unit in 1,000-unit quantities for the 64-pin LFQFP package, 128 KB of on-chip memory configuration.

For more information on the RL78/G23, visit:

The reference price for the Fast Prototyping Board is US$21.00 per unit. 

For more information on the evaluation kit, visit:

Note 1: An event link controller (ELC) provides functionality that allows events to be directly linked to peripheral functions, bypassing the CPU. This enables events to rapidly activate modules directly, without going through the controller. It also contributes to reduced power consumption because events can activate modules even when the CPU is in sleep mode.

Tiera Oliver, Associate Editor for Embedded Computing Design, is responsible for web content edits, product news, and constructing stories. She also assists with newsletter updates as well as contributing and editing content for ECD podcasts and the ECD YouTube channel. Before working at ECD, Tiera graduated from Northern Arizona University where she received her B.S. in journalism and political science and worked as a news reporter for the university’s student led newspaper, The Lumberjack.

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