描述： only 42 single word instructions all instructions are single cycle except for program branches which are two-cycle 13-bit wi de instructions all eprom area goto instruction all eprom area subroutine call instruction 8-bit wide data path 5-level deep hardware stack operating speed: dc-20 mhz clock inpu dc-100 ns instruction cycle device pins # i/o # eprom (word) ram (byte) fm8pb513b 8 6 1k 49 direct, indirect addressing modes for data accessing 8-bit real time clock/counter (timer0) with 8-bit programmable prescaler internal power-on reset (por) built-in low voltage detector (lvd) for brown-out reset (bor) power-up reset timer (pwrt) and oscillator start-up timer(ost) on chip watchdog timer (wdt) with internal oscillator for reli able operation and soft-ware watch-dog enable/disable control one i/o port iob with independent direction control soft-ware i/o pull-high/pull-down or open-drain control one internal interrupt source: timer0 overflow; two external interrupt source: int pin, port b input change wake-up from sleep by int pin or port b input change power saving sleep mode built-in 8mhz, 4mhz, 1mhz, and 455khz internal rc oscillator programmable code protection selectable oscillator options: - erc: external resistor/capacitor oscillator - hf: high frequency crystal/resonator oscillator - xt: crystal/resonator oscillator - lf: low frequency crystal oscillator - irc: internal resistor/capacitor oscill ator - eric: external resistor/internal capacitor oscillator wide-operating voltage range: 2.0v to 5.5v