[Hyundai Micro Electronics]

Description
The GMS81C2020 and GMS81C2120 are an advanced CMOS 8-bit microcontroller with 20K/12K bytes of ROM. These are a powerful microcontroller which provides a highly flexible and cost effective solution to many VFD applications. These provide the following standard features: 20K/12K bytes of ROM, 448 bytes of RAM, 8-bit timer/counter, 8-bit A/D converter, 10-bit High Speed PWM Output, Programmable Buzzer Driving Port, 8-bit Basic Interval Timer, 7-bit Watch dog Timer, 8-bit, Serial Peripheral Interface, on-chip oscillator and clock circuitry. They also come with high voltage I/O pins that can directly drive a VFD(Vacuum Fluorescent Display). In addition, the GMS81C2020 and GMS81C2120 support power saving modes to reduce power consumption.

 Features
• 20K/12K bytes ROM(EPROM)
• 448 Bytes of On-Chip Data RAM (Including STACK Area)
• Minimum Instruction Execution time :
    - 1uS at 4MHz ( 2cycle NOP Instruction )
• One 8-Bit Basic Interval Timer
• One 7-Bit Watch Dog Timer
• Two 8-Bit Timer/Counters
• 10-Bit High Speed PWM Output
• One 8-bit Serial Peripheral Interface
• Two external interrupt ports
• One Programmable 6-Bit Buzzer Driving port
• 60 I/O Lines
    - 56 Programmable I/O pins : 30 high-voltage pins (40V,max)
    - 3 Input Only pins : 1 high-voltage pin
    - 1 Output Only pin
• Eight Interrupt Sources
    - 2 By External Sources (INT0, INT1)
    - 2 By Timer/Counter Sources (Timer0, Timer1)
    - 4 By Functional Sources (SPI,ADC,WDT,BIT)
• 12-Channel 8-Bit On-Chip Analog to Digital Converter
• Oscillatior :
    - Crystal
    - Ceramic Resonator
    - External RC Oscillator
    - Internal RCWDT Oscillatior
• Low Power Dissipation Modes
    - STOP mode
    - Wake-up Timer Mode
    - Standby Mode
    - Watch Mode
    - Subactive Mode
• Operating Voltage : 4.0V ~ 5.5V (at 4.5MHz)
• Operating Frequency : 0.4MHz ~ 4.5MHz
• Subclock : 32.768KHz Crystal Oscillator
• Enhanced EMS Improvement Power Fail Processor ( Noise Immunity Circuit )