˙Only 42 single word instructions
˙5-level deep hardware stack
˙8-bit real time clock/counter(Timer0) with 8-bit programmable prescaler
˙On chip Watchdog Timer (WDT) with internal oscillator for reliable operation
and soft-ware watch-dog enable/disable control
˙2 I/O ports with independent direction control
˙Soft-ware I/O pull-high/pull-down or open-drain control
˙1 internal interrupt source; 2 external interrupt source
˙Wake-up from SLEEP mode
˙Built-in 8MHz, 4MHz, 1MHz, and 455KHz internal RC oscillator