Minimum instruction execution time can be changed from high speed (0.03125 s: @ 32 MHz operation with highspeed on-chip oscillator clock) to ultra low-speed (30.5 s: @ 32.768 kHz operation with subsystem clock)  General-purpose register: 8 bits  32 registers (8 bits  8 registers  4 banks)  ROM: 24 to 256 KB, RAM: 2 to 16 KB, Data flash memory: 8 KB  On-chip high-speed on-chip oscillator clocks  Select from 32 MHz (TYP.), 24 MHz (TYP.), 16 MHz (TYP.), 8 MHz (TYP.), and 4 MHz (TYP.)  On-chip single-power-supply flash memory (with prohibition of block erase/writing function)  Self-programming (with boot swap function/flash shield window function)  On-chip debug function  On-chip power-on-reset (POR) circuit and voltage detector (LVD)  On-chip watchdog timer (operable with the dedicated low-speed on-chip oscillator clock)