概要 this eprom-based 8-bit micro-controller uses a fully static cmos design technology combines higher speeds and smaller size with the low power and high noise immunity of cmos. on chip memory system includes 0.5 k(for mdt2005) bytes of rom, and 32 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 rom size : 512 words; ◆internal ram size : 32 bytes(25 general purpose registers, 7 special registers); ◆36 single word instructions; ◆14-bit instructions; ◆2-level stacks; ◆operating voltage : 2.3v ~ 6.5 v; ◆operating frequency : 0 ~ 20 mhz; ◆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(por), only available while ped is disable ◆power edge-detector reset(ped) ◆sleep mode for power saving ◆8-bit real time clock/counter(rtcc) with 8-bit programmable prescaler ◆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 ◆4 oscillator start-up time can be selected by programming option: --20 ms, 40 ms, 80 ms ◆on-chip rc oscillator based watchdog timer (wdt)can be operated freely ◆12 i/o pins with their own independent direction control