Overview
Description
The Renesas RL78/L23 microcontroller has an RL78-S3 CPU core and rich peripheral features to deliver a better design experience that allows high-level system design while reducing power consumption, system cost, and overall footprint through an extensive range of peripheral functions and low-power operation. RL78/L23 is designed to meet the dynamic requirements of human-machine interface (HMI) applications, featuring capabilities such as capacitive touch sensing and segment LCD control. Additionally, HMI application systems can stay up-to-date, since RL78/L23’s dual-bank flash memory enables continuous firmware updating without interrupting system operation. RL78/L23 also supports rich timer functions including 16-bit general-purpose timers, 32-bit and 16-bit low-power inverter timers, 16-bit Timer RJ, 16-bit Timer KB, and RTC. Timer KB can generate up to 3 channels of PWM signals suitable for controlling power supplies, lighting, and inductive heating (IH) control.
Features
- 32MHz Renesas RL78-S3 CPU core
- 512KB flash (dual bank) and 32KB SRAM
- 8KB data flash memory (100,000 program/erase (P/E) cycles)
- 44-pin to 100-pin package lineup with a wide variety of package options including LQFP, LFQFP, and HWQFN
- Built-in LCD controller supporting 19 to 56 segment signal outputs and 4 to 8 common signal outputs
- Capacitive sensing unit supports up to 36ch
- Rich timer functions including 16-bit general purpose timers, 32-bit and 16-bit low-power inverter timers, 16-bit Timer RJ, 16-bit Timer KB, and RTC
- 12-bit A/D converter, 8-bit D/A converter, comparator, and temperature sensor
- SCI (UART, Simple SPI, Simple I2C), SPI, and I2C bus
Comparison
Applications
Design & Development
Software & Tools
Sample Code
Boards & Kits
Models
ECAD Models
Schematic symbols, PCB footprints, and 3D CAD models from SamacSys can be found by clicking on the CAD Model links in the Product Options table. If a symbol or model isn't available, it can be requested directly from SamacSys.
Support
Support Communities
Resources
FAQs
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RL78/L23: 8-bit interval timer
Yes, the 8-bit interval timer on the RL78/L23 can be used as a 16-bit interval timer by connecting two channels.This also allows for applications that require longer timer cycles and precise time management.The RL78/L23 also allows channel 0 and channel 1 of ...
Aug 27, 2025 -
RL78/L23: Boot cluster resizing, bank swap settings
It can be configured using the dedicated flash memory programmer PG-FP6 or Renesas Flash Programmer (Programming GUI).The bank swap settings can also be set in the properties of the e2 studio and CS+ debugger, but the boot cluster size must be done in a dedicated flash memory programmer.
Aug 27, 2025 -
RL78/L23: Segment LCD
Yes. The RL78/L23 is equipped with a segmented LCD that supports 6 commons. The RL78/L23 is available in the following configurations: 4 Commons × 56 Segments, 6 Commons × 54 Segments, 8 Commons × 52 Segments
Aug 27, 2025
Videos & Training
The RL78/L23 MCU combines ultra-low power operation with rich peripheral features, enabling high-level system design for consumer and industrial HMI applications. It supports capacitive touch sensing, segment LCD control, and advanced timer functions while minimizing system cost and footprint. With dual-bank flash memory, RL78/L23 allows seamless firmware updates without interrupting system operation.
Related Resources
News & Blog Posts
News
Aug 27, 2025
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Blog Post
Aug 27, 2025
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