概要 this eprom-based 8-bit micro-controller uses a fully static cmos technology process to achieve higher speed and smaller size with the low power consump-tion and high noise immunity. on chip memory incl-udes 1k words of rom, and 68 bytes of static ram. 特点 the followings are some of the features on the hardware and software : ◆fully cmos static design; ◆8-bit data bus; ◆on chip eprom size : 1k words; ◆internal ram size : 84 bytes(68general purpose registers, 16 special registers); ◆37 single word instructions; ◆14-bit instructions; ◆8-level stacks; ◆operating voltage : 2.5v ~ 5.5 v(prd disable); 4.5v ~ 5.5 v(prd enable); ◆operating frequency : dc ~ 20 mhz; ◆the most fast execution time is 200 ns under 20 mhz in all single cycle instructions except the branch instruction ◆addressing modes include direct, indirect and relative addressing modes ◆power-on reset ◆power edge-detector reset ◆power range-detector reset ◆sleep mode for power saving ◆four interrupt sources: --external int pin --tmr0 timer --a/d conversion completion --portb interrupt on change ◆a/d converter module: --four analog inputs multiplexed into one a/d converter --8-bit resolution ◆4 types of oscillator can be selected by programming option: --rc－low cost rc oscillator --lfxt－low frequency crystal oscillator --xtal－standard crystal oscillator --hfxt－high frequency crystal oscillator ◆8-bit real time clock/counter(rtcc) with 8-bit programmable prescaler ◆on-chip rc oscillator based watchdog timer (wdt) ◆13 i/o pins with their own independent direction control