1. general description 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 inclu-des 1k words of rom, and 41 bytes of static ram. 2. features the followings are some of the features on the hardware and software : ? fully coms static design ? 8-bit data bus ? on chip eprom size : 1 k words ? internal ram size : 41 bytes ? 36 single word instructions ? 14-bit instructions ? 2-level stacks ? operating voltage : 2.5 v ~ 5.0 v ? operating frequency : 4 mhz or 8 mhz ? the most fast execution time is 500 ns under 8 mhz in all single cycle instructions except the branch instruction ? addressing modes include direct, indirect and relative addressing modes ? power-on reset ? sleep mode for power saving ? oscillator mode: intrc－internal 4/8 mhz rc oscillator ? power on start-up time : 20 ms ? 8-bit real time clock/counter(rtcc) with 8-bit programmable prescaler ? on-chip rc oscillator based watchdog timer(wdt) ? wake-up from sleep on pin change3. applications the application areas of this p509(a) range from appliance motor control and high speed automotive to low power remote transmitters/receivers, small instruments, chargers, toy, automobile and pc pe-ripheral … etc.