DESCRIPTION
µPD17225, 17226, 17227, 17228 (hereafter called µPD17225 subseries) are 4-bit single-chip microcontrollers for small general-purpose infrared remote control transmitters.
It employs a 17K architecture of general-purpose register type devices for the CPU, and can directly execute operations between memories instead of the conventional method of executing operations through the accumulator. Moreover, all the instructions are 16-bit 1-word instructions which can be programmed efficiently.
In addition, a one-time PROM model, µPD17P218, to which data can be written only once, is also available. It is convenient either for evaluating the µPD17225 subseries programs or small-scale production of application systems.

FEATURES
• Infrared remote controller carrier generator circuit (REM output)
• 17K architecture: General-purpose register system
• Program memory (ROM), Data memory (RAM)
• 8-bit timer : 1 channel
• Basic internal timer/Watchdog timer : 1 channel (WDOUT output)
• Instruction execution time (can be changed in two steps) at fX = 4 MHz : 4 µs (high-speed mode)/8 µs (ordinary mode) at fX = 8 MHz : 2 µs (high-speed mode)/4 µs (ordinary mode)
• External interrupt pin (INT) : 1
• I/O pins : 20
• Supply voltage : VDD = 2.2 to 3.6 V (at fX = 8 MHz (high-speed mode)) VDD = 2.0 to 3.6 V (at fX = 4 MHz (high-speed mode))
• Low-voltage detector circuit (mask option)

APPLICATION
    Preset remote controllers, toys, portable systems, etc.