Low power consumption, compact LCD microcontrollers suitable for small appliances and healthcare devices


RL78/L12 microcontrollers have a built-in segment LCD driver. Three LCD driving voltage generation methods (external resistance division, capacitive split, and internal voltage boost) are supported, corresponding to a variety of segment LCD panels. They realize low current consumption (*1): external resistance division: 1.60 μA (*2), internal voltage boost: 1.19 μA, and capacitive split: 0.68 µA. With a lineup of 32 to 64-pin products supporting up to 280 segments, these microcontrollers are perfect for small devices with built-in LCD panels such as small appliances and healthcare devices.

(*1) Current (typ.) at 1/3 bias, subclock operation, HALT mode, and RTC operation
(*2) Resistance value for external resistance division = 1000 kΩ


Key Features:

ITEM Rl78/L12
Pin Count 32pins 44pins 48pins 52pins 64pins
Part Name R5F10RBx R5F10RFx R5F10RGx R5F10RJx R5F10RLx
Memory Program Flash 8 to 32 KB 16, 32 KB
Data Flash 2 KB
SRAM 1, 1.5 KB
Clock High speed system clock
  • X1(crystal/ceramic) oscillation, external main system clock input (EXCLK)
    1 to 20 MHz:VDD = 2.7 to 5.5 V
    1 to 16 MHz:VDD = 2.4 to 5.5 V
  • 1 to 8 MHz:VDD = 1.8 to 5.5 V
    1 to 4 MHz:VDD = 1.6 to 5.5 V
High speed on-chip oscillator
  • HS(high-speed main) mode: 1 to 24 MHz(VDD = 2.7 to 5.5 V)
  • HS(high-speed main) mode: 1 to 16 MHz(VDD = 2.4 to 5.5 V)
  • LS(low-speed main) mode: 1 to 8 MHz (VDD = 1.8 to 5.5 V)
  • LV(low-voltage main) mode: 1 to 4 MHz (VDD = 1.6 to 5.5 V
Sub system clock - XT1(crystal) oscillation, external system clock input(EXCLKS) 32.768 kHz(TYP.):VDD = 1.6 to 5.5 V
Low speed on-chip oscillator Internal oscillation
15 kHz(TYP.):VDD = 1.6 to 5.5 V
I/O port Total 20 29 33 37 47
CMOS I/O 15 22 26 30 39
CMOS input 3 5
CMOS output - 1
N-ch open Drain I/O (EVDD) 2
Pins only for LCD drive 8 11
LCD controller/driver Method Internal voltage boosting method, capacitor split method, and external resistance division method are switchable.
Segment signals 13 22(18) 26(22) 30(26) 39(35)
Common signals 4 4(8)
Timer 16-bit timer 8 channels 8 channels (Remote control output 1 channel)
Watchdog timer 1 channel
Real Time Clock
1 channel
12-bit interval timer (IT) 1 channel
Timer output 4 (PWM:3) 5 (PWM:4) 6 (PWM:5) 8 (PWM:7)
RTC output - 1 channel : 1 Hz (Sub system clock: fSUB = 32.768 kHz)
8/10-bit A/D converter 4 channels 7 channels 9 channels 10 channels
Serial interfaces CSI 2ch/UART(LIN-Bus support) 1 channel
I2C-bus 1 channel
DMA controller 2 channels
Vector interrupt source Internal 23
External 4 6 7 7 9
Key interrupt 4
Other peripherals Low voltage detection, Power-On Reset, Clock output/Buzzer function
Safety Function
  • RAM parity error detection
  • Invalid memory access detection
  • Frequency detection
  • A/D converter testing
  • CRC operations
  • RAM guarding
  • SFR guarding
On-chip debug function Available
Power supply voltage VDD = 1.6 to 5.5 V
Operating ambient temperature TA = -40 to + 85 ℃ for A-Version product / -40 to + 105 ℃ for G-Version product

Pin Count / Memory Size Lineup:

Program Flash

  •  RL78/L12
  •  RL78/L13


Block Diagram:

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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Software Design Support

Title Description
e² studio This integrated development environment (IDE) is based on the popular combination of the open-source Eclipse IDE and its CDT plug-in that enables C/C++ language development.
CS+ This integrated development environment (IDE) can be used for coding, assembly, compiling, and simulation. CS+ is also included with starter kits.
E2 emulator Lite This entry-level on-chip debugging emulator provides functionality equivalent to that of the E1 emulator at a low price.
E2 emulator This on-chip debugging emulator has advanced features that improve the efficiency of development. In addition to the basic functions from debugging to flash programming, this emulator supports hot plug-in and external triggers as standard items. This emulator also helps to reduce development time by downloading at high speeds (compared to the E1 emulator) and the ability to work in combination with various solutions such as the tuning of current drawn by systems under development.
E1 emulator This on-chip debugging emulator is a standard model which provides basic debugging functions (production is to be discontinued at the end of December 2019).


Hardware Design Support

Title Description
Characteristics data Information on observed values. Please use this as reference data when developing your set.
Oscillation circuit characteristics The resonators for which the operation is verified and their oscillator constants are shown below.
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