Achieving Efficient and Secure Communications with the RL78/F25
The architecture trend is moving from distributed to domain Electronic Control Unit (ECU) and zone ECU to integrated control of the entire vehicle. This shift creates new challenges: the actuator ECU is required to improve data transfer speed, payload capacity, and reliability when communicating with the integrated control ECU. The RL78/F25 microcontroller (MCU) is designed to meet these requirements directly. Like the RL78/F24 MCU, it features CAN FD with support for speeds up to 5Mbps and 20 buffers with 64-byte payloads, as well as security functionalities including AESEA and TRNG for secure boot and message authentication. These attributes make the RL78/F25 a strong candidate for implementing high-reliability smart actuators, sensors, and entry-level body ECUs. In addition, the code flash memory has been expanded to 512KB, which improves the response to more complex applications, software platforms like AUTOSAR, and the implementation of Functional Safety (FuSa).
RL78/F25 meets ISO/SAE 21434 (Cyber Security) and ISO 26262 (Functional Safety) standards, supporting ASIL B for FuSa and Evita-light for secure communication with low-power, cost-effective sensors and actuators. It features AES encryption with keys up to 256 bits and is the first RL78 automotive product with a CTSU2SLa capacitive sensing unit.
RL78/F25 Features
- Maximum operating frequency: 40MHz
- Memory: Code Flash 512KB, Data Flash 16KB, RAM 40KB
- Peripheral Functions: Capacitive sensing unit (Max31ch), CAN/CAN FD (2ch), LIN (3ch), 12-bit A/D converter (29ch, dedicated S&H2ch), D/A converter, comparator, motor control timer TimerRDe, Application Accelerator Unit (AAU), etc.
- Package: 48-pin to 100-pin LFQFP
- Low power consumption: Typ. 0.6µA (Stop mode)
- Security: AES-ECB/CBC/CMAC key lengths 128/192/256-bit, TRNG
- Ambient temperature range (Ta): -40°C ～ +105/125°C
The RL78/F25 shares many features with RL78/F1x and RL78/F2x, and is hardware and software compatible, enabling PCB and software reuse.
Advanced Touch Functions
Compared to former versions of Renesas' Capacitive Touch Sensing Unit (CTSU), the CTSU2SLa offers improved noise immunity, water resistance, and lower power consumption. It also features:
- Multi-Frequency Scanning: Generates three capacitance measurement clocks to reduce the effects of synchronized disturbance noise.
- Active Shield: The touch electrode and shield guard electrode are driven at the same potential and phase to suppress the effects of water adhesion.
- Automatic Judgement: Detects button touches in hardware without the need for a CPU.
- Multiple Electrode Connection (MEC): Reduces touch event measurement time and current consumption by measuring multiple touch electrodes as a single electrode.
CTSU | CTSU2 | CTSU2L | CTSU2La | CTSU2SL | CTSU2SLa | |
|---|---|---|---|---|---|---|
| Self-Capacitance Method | ||||||
| Mutual-Capacitance Method | ||||||
| Random Pulse Frequency Measurement | ||||||
| Multi-Frequency Measurement (Multi-Clock Scan) | N/A | |||||
| Active Shield | N/A | |||||
| Touch Judgement Hardware | N/A | N/A |
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| Multiple Electrode Connection (MEC) | N/A | N/A | N/A | |||
| Multiple Capacitance Parallel Measurement (CFC) | N/A | N/A | N/A | N/A | N/A | |
| MCU Products | RX113 | RA2L1, RA2E1 | RL78/G23 | RL78/G22 | RX140 | RL78/F25 |
Development Tools
Easy Initial Configuration with Smart Configurator
The Smart Configurator is a user-friendly GUI tool that enables automatic and easy generation of initial configuration programs. The Smart Configurator has a well-proven track record that is supported by many Renesas microcontrollers, enabling speedy and smart software development for customer applications.
Ready-to-Try Evaluation Boards and Evaluation Systems that Ease Solution Development
Two types of evaluation boards are available for the RL78/F25 MCU.
RL78/F25 Target Board
The RL78/F25 Target Board is an evaluation board specialized for prototype development, and using the E2/E2-lite emulator enables writing/debugging of programs. Also, two touch buttons are provided for easy capacitive touch evaluation.
Capacitive Touch Evaluation System
The Capacitive Touch Evaluation System for RL78/F25 is an evaluation board specialized for capacitive touch evaluation that includes a switch, slider, and wheel. By combining it with QE for Capacitive Touch, a touch development support tool that allows users to develop touch I/F with just simple operations, evaluation can start immediately after purchase.
The RL78 has been widely adopted by numerous customers over the years. The RL78/F25 offers features such as 512KB ROM, dual-channel CAN FD, security functions, functional safety (FuSa), and a capacitive sensing unit, making it suitable for a diverse range of applications. We provide an extensive selection of evaluation boards, development tools, and solutions designed to facilitate a seamless start for users. To learn more about RL78/F25, visit renesas.com/rl78f25.