Microcontrollers for automotive low-end instrument clusters with built-in features such as sound generator, stepper motor controller/driver, and segmented LCD driver


RL78/D1A microcontrollers have a built-in sound generator which can set a volume level and tone frequency of 100 Hz to 6 kHz and has an automatic volume decrement function, up to four channels of stepper motor controller/driver which can set an 8-bit precision (pseudo 9-bit precision using a 1-bit addition function) pulse width (PWM output), and an LCD controller/driver which supports up to 216 segments. The 128-pin version has a built-in LCD bus interface and two channels of CAN, and expanded flash memory/RAM up to a maximum of 512 KB/24 KB, making these microcontrollers ideal for low-end instrument cluster.


Main Solutions

Key Features:

ITEM RL78/D1A(Autmotive Only)
Pin Count 48 pin 64 pin 80 pin 100 pin 128 pin
Memory Program Flash 24 to 64 KB 48 to 64 KB 48 to 256 KB 64 to 512 KB 256 to 512 KB
SRAM 2 to 4 KB 3 to 4 KB 3 to 16 KB 4 to 24 KB 16 to 24 KB
Data Flash 8 KB
Register General purpose register : 8-bit x 32 registers (8-bit x 8 registers x 4 banks)
Clock High speed system clock: 1 to 20 MHz (VDD = 2.7 - 5.5 V)
High speed internal oscillator: 32, 24, 16, 8, 4 MHz (Ta = - 40 to +85 ℃) / 24, 16, 8, 4 MHz (Ta = -40 to +105 ℃)
Low speed internal oscillator: 15 kHz, Sub system clock: 32.768 kHz
I/O Port (I/O, In, Out) 38 (35, 3, 0) 54 (49, 5, 0) 68 (63, 5, 0) 84 (78, 5, 1) 112 (107, 5, 1)
Timer 16-bit 8 channels x3 units
Real Time Clock (RTC) 1 channel
Interval Timer 1 channel
Watchdog Timer 1 channel
Output 24 channels
RTC output 1 channel
10-bit A/D converter 3 + 2 channels 6 + 2 channels 7 + 2 channels 9 + 2 channels
Serial Interfaces CSI 2 channels 3 channels
UART - 1 channel
Simplify I2C 1 channel
LIN-UART 2 channels
CAN 0 or 1 channel 0 or 1 channel 0 or 1 channel 1 or 2 channels 2 channels
DMA controller 2 channels 4 channels
Stepper motor controller / driver(with ZPD) 1 channel 2 channels 4 channels
LCD controller/driver 27 seg. x4 com. 39 seg. x4 com. 48 seg. x4 com. 53 seg. x4 com. 54 seg. x4 com.
LCD bias Static, 1 / 3 bias, 1 / 4 duty
LCD bus interface - 8-bit read/write
Sound generator Supported
Power supply voltage 2.7 to 5.5 V
Operating ambient temperature J grade products Ta = - 40 to + 85 ℃ / L grade products Ta = - 40 to +105 ℃

Pin Count / Memory Size Lineup:

Program Flash



Block Diagram:

RL78/D1A(Automotive Only) Block Diagram

You can find an explanation of orderable part numbers here.


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Software Design Support

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E2 emulator Lite This entry-level on-chip debugging emulator provides functionality equivalent to that of the E1 emulator at a low price.
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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).
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