DESCRIPTION
The 3874 group is the 8-bit microcomputer based on the 740 family core technology.
The 3874 group includes data link layer communication control circuit, A-D converters, D-A converter, automatic data transfer serial I/O, UART, and watchdog timer etc.

FEATURES
● Basic machine-language instructions ...................................... 71
● Minimum instruction execution time................................. 0.32 µs
    (at 6.4 MHz oscillation frequency, in double-speed mode)
● Memory size
    ROM ............................................................... 16 K to 60 K bytes
    RAM ............................................................... 1024 to 2048 bytes
● Programmable input/output ports ............................................ 72
● Input port .................................................................................... 1
● Interrupts ................................................. 27 sources, 16 vectors
    (Interrupt source discrimination register exists, included key input interrupt)
● Timer 1, timer 2, timer 3 ................................................. 8-bit ✕ 3
● Timer X, timer Y............................................................ 16-bit ✕ 2
● Serial I/O1 .................... 8-bit ✕ 1(UART or Clock-synchronized)
● Serial I/O2 ................................... 8-bit ✕ 1(Clock-synchronized)
● Serial I/O3 ...................................................................... 8-bit ✕ 1
    (Clock-synchronized automatic data transfer/arbitrary bit transfer function available)
● A-D converter ................................................. 8-bit ✕ 8 channels
● D-A converter ................................................... 8-bit ✕ 1 channel
● Data link layer communication control circuit ............................ 1
● Clock generating circuit..................................... Built-in 2 circuits
    (connect to external ceramic resonator or quartz-crystal oscillator)
● Watchdog timer ............................................................ 20-bit ✕ 1
● Power source voltage ................................................ 3.0 to 5.5 V
● Power dissipation
    In double-speed mode ......................................................90 mW
    In high-speed mode ..........................................................60 mW
    (at 32 kHz oscillation frequency, at 5 V power source voltage)
    In low-speed mode .......................................................... 180 µW
    (at 32 kHz oscillation frequency, at 3 V power source voltage)
● Operating temperature range.................................... –40 to 85°C
    (Extended operating temperature version and automotive version)

APPLICATION
    Automotive comfort control for audio system, air conditioning etc., automotive body electronics control, household appliances, and other consumer applications, etc.