The 78K0R/Kx3-L Group is supported only for the customers who have already adopted any of the products. For new adoption, please consider other products such as RL78/G13, RL78/G1F Group.

Main Solutions

Key Features:

  • Operating voltage: VDD = 1.8 to 5.5 V
  • Max. frequency: 20 MHz
  • ROM capacities: 16 KB to 128 KB flash memory
  • RAM capacities: 1 KB to 8 KB
  • Package: 48-pin TQFP package, 44-pin, 52-pin, 64-pin, 80-pin, 100-pin LQFP package
  • Minimum instruction execution time can be changed from high speed (0.05 ?s: @ 20 MHz operation with highspeed system clock) to ultra low-speed (61 ?s: @ 32.768 kHz operation with subsystem clock)
  • General-purpose register: 8 bits x 32 registers (8 bits x 8 registers x 4 banks)
  • On-chip internal high-speed oscillation clocks
    • 20 MHz Internal high-speed oscillation clock: 20 MHz±1 % (target)
    • 8 MHz Internal high-speed oscillation clock: 8 MHz±1 % (target)
    • 1 MHz Internal high-speed oscillation clock: 1 MHz±5 %


  • On-chip single-power-supply flash memory (with prohibition of chip erase/block erase/writing function)
  • Self-programming (with boot swap function/flash shield window function)
  • On-chip debug function
  • On-chip power-on-clear (POC) circuit and low-voltage detector (LVI)
  • On-chip watchdog timer (operable with the dedicated internal low-speed oscillation clock)
  • On-chip multiplier/divider (16 bits x 16 bits, 32 bits / 32 bits)
  • On-chip key interrupt function
  • On-chip clock output/buzzer output controller
  • On-chip BCD adjustment
  • I/O ports:
    • 37 : 44-pin products
    • 41 (N-ch open-drain 2) : 48-pin products
    • 45 (N-ch open drain 2) : 52-pin products
    • 55 (N-ch open drain 2) : 64-pin products
    • 71 (N-ch open drain 4) : 80-pin products
    • 89 (N-ch open drain 4) : 100-pin products


  • Timer: 10/14 channels
    • 16-bit timer: 8/12 channels
    • Watchdog timer: 1 channel
    • Real-time counter: 1 channel


  • On-chip comparator/programmable gain amplifier function
  • Serial interface
    • CSI: 2 channels/UART: 1 channel
    • CSI: 1 channel/UART: 1 channel/simplified I2C: 1 channel
    • CSI: 1 channel/UART: 1 channel/simplified I2C: 1 channel
    • UART (LIN-bus supported): 1 channel - I2C: 1 channel


  • 10-bit resolution A/D converter (AVREF = 1.8 to 5.5 V): 10 to 12 channels
  • Operating ambient temperature: TA = -40 to +85°C


Pin Count / Memory Size Lineup:

78K0R/Kx3-L-Pin Count/Memory Size

Below you will find information to support the development of your application.
You can find an explanation of orderable part numbers here.


Resources for Software and Hardware

Title Description
My Renesas Create a My Renesas account to use our tool download services, receive e-newsletter/update notifications, and take advantage of our other services.
e-learning Information for studying and learning about microcontrollers and microprocessors.
FAQ Frequently asked questions and useful hints for development.
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Video Watch videos related to this product.


Software Design Support

Title Description
CS+ An integrated development environment that can be used for coding, assembling/compiling, and simulation. (Also included with Renesas Starter Kits.)
E1 A standard Renesas on-chip debugging emulator that enables users to carry out ample debugging for real development at low cost. (Also included with starter kits.)


Hardware Design Support

Title Description
Characteristics data Information on observed values. Please use this as reference data when developing your set.
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