Adam Korbel
Senior Staff Engineer
Published: October 14, 2020

Did you know that Renesas leads the automotive market in the 16-bit MCU low-end vehicle control segment? This is an interesting fact because the RL78/F1x, and its predecessors, the 78K0R and R8C, both have cores that are Renesas proprietary, while the competition is offering Arm® based cores in their latest MCU. The RL78 core offers many exclusive interrupts instead of "collective" interrupts. Due to its better interrupt latency performance, the RL78 is the best choice for event-driven applications such as those required in actuator or sensor ECUs. Best-in-class power consumption and high compute performance, are both possible at low frequency with 1.64 DMIPs/MHz (24MHz at 125 °C/150 °C, 32MHz at 105 °C).

The RL78F13/F14/F15 MCUs were realized in 130nm MF3 CMOS technology with AEC-Q100 automotive grading. The RL78 microcontroller line-up offers outstanding wide scalability over memory size (16kB to 512kB), package variants (PIN#: 20-pin to 144-pin; PKG type: SOP, QFN and QFP), and temperature grades (105 °C product, 125 °C product, 150 °C product). This is a great benefit for customers because it ensures high flexibility and freedom to change for example to a different memory size in case of unexpected application software size.

Our RL78 MCU series was developed in close collaboration with our key automotive customers allowing for successful implementation of a clever automotive application-tailored feature set. Other built-in features, such as high-precision, high-speed, on-chip oscillators, background operation data flash capable of min. 100k rewrites help to reduce the system cost and size.

Application examples:

  • Half-bridge and H-bridge motor control, BLDC motor control on block commutation and even based on field-oriented-control (FOC) for HVAC application
  • Sensor ECU: For temperature/pressure/light/rain/humidity/position/particle detection up to 150 °C ambient temperature is unique and makes it the best choice to work reliably in extreme environmental conditions.
  • RL78 MCU is recommended in the majority for non-Autosar based application up to 512kB Flash based on LIN or CAN communication standards.

Renesas is now under planning for next-generation RL78 products again with 130nm CMOS technology node in order to adapt to the recent market demands on Functional Safety and Security for various actuator applications while keeping affordable cost and power consumptions. What is the motivation to keep the same 130nm MF3 CMOS process for the future when Renesas is promoting 28nm and beyond for other MCUs? The MF3 process has outstanding low leakage currents and industry-leading power efficiency with low power consumption. By using these improved RL78 MCU microcontrollers, customers who already have established RL78-based MCU platforms will enjoy a high grade of software re-use which is a great benefit to reduce development time for a quicker time-to-market.

For new projects/customers and emerging markets, rapid product development with RL78 is possible while using few development resources: 


The free-of-charge APPILET code generator software can be used. Without reading the datasheet, all peripherals can be initialized, and an IAR project with sample software can be generated for the Starter Kit hardware development. Autosar software is not required for 16-bit MCU devices. Many RL78 application notes and software libraries are available as well, and customers can start development quicker, with less effort compared with 32-bit MCUs.

Please visit the RL78 Low Power 8 & 16-bit MCUs page on our website for more technical detail about the highly scalable RL78 MCU series and to check out the parametric search engine.

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