Description
   The HMS77C1000A and HMS77C1001A are an advanced CMOS 8-bit microcontroller with 0.5K/1K words(12-bit) of EPROM. The Hynix Semiconductor HMS77C1000A and HMS77C1001A are a powerful microcontroller which provides a high flexibility and cost effective solution to many small applications. The HMS77C1000A and HMS77C1001A provide the following standard features: 0.5K/1K words of EPROM, 25 bytes of RAM, 8-bit timer/counter, power-on reset, on-chip oscillator and clock circuitry. In addition, the HMS77C1000A and HMS77C1001A supports power saving modes to reduce power consumption.

FEATUREs
• High-Performance RISC CPU:
   - 12-bit wide instructions and 8-bit wide data path
   - 33 single word instructions
   - 0.5K/1K words on-chip program memory
   - 25 bytes on-chip data memory
   - Minimum instruction execution time
      200ns @20MHz
   - Operating speed: DC - 20 MHz clock input
   - Seven special function hardware registers
   - Two-level hardware stack

• Peripheral Features:
   - Twelve programmable I/O lines
   - One 8-bit timer/counter with 8-bit programmable
      prescaler
   - Power-On Reset (POR)
   - Power Fail Detector : noise immunity circuit
                                    2 level detect ( 2.7V, 1.8V )
   - Internal Reset Timer (IRT)
   - Watchdog Timer (WDT) with on-chip RC oscillator
   - Programmable code-protection
   - Power saving SLEEP mode
   - Selectable oscillator options: Configuration word
      RC: Low-cost RC oscillator (200KHz~4MHz)
      XT: Standard crystal/resonator (455KHz~4MHz)
      HF: High-speed crystal/resonator (4~20MHz)
      LF: Power saving, low-frequency crystal/resonator
         (32~200KHz)

• CMOS Technology:
   - Low-power, high-speed CMOS EPROM technology
   - Fully static design
   - Wide-operating range:
      2.5V to 5.5V @ RC, XT, LF
      4.5V to 5.5V @ HF