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

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