GENERAL DESCRIPTION
The DS89C420 offers the highest performance available in 8051-compatible microcontrollers. It features a redesigned processor core that executes every 8051 instruction (depending on the instruction type) up to 12 times faster than the original for the same crystal speed. Typical applications see a speed improvement of 10 times using the same code and crystal. The DS89C420 offers a maximum crystal speed of 33MHz, achieving execution rates up to 33 million instructions per second (MIPS).

FEATURES
■ 80C52 Compatible
    - 8051 Pin and Instruction-Set Compatible
    - Four Bidirectional I/O Ports
    - Three 16-Bit Timer Counters
    - 256 Bytes Scratchpad RAM
■ On-Chip Memory
    - 16kB Flash Memory
    - In-System Programmable through Serial Port
    - 1kB SRAM for MOVX
■ ROMSIZE Feature
    - Selects Internal Program Memory Size from 0 to 16k
    - Allows Access to Entire External Memory Map
    - Dynamically Adjustable By Software
■ 80C52 compatible
    - 8051 pin and instruction-set compatible
    - Four bidirectional I/O ports
    - Three 16-bit timer counters
    - 256 bytes scratchpad RAM
■ On-chip memory
    - 16kB flash memory
    - In-system programmable through serial port
    - 1kB SRAM for MOVX
■ ROMSIZE feature
    - Selects internal program memory size from 0 to 16k
    - Allows access to entire external memory map
    - Dynamically adjustable by software
■ High-speed architecture
    - 1 clock-per-machine cycle
    - DC to 33MHz operation
    - Single-cycle instruction in 30ns
    - Optional variable length MOVX to access fast/slow peripherals
    - Dual data pointers with auto increment/decrement and toggle select
    - Supports four paged modes
■ Power Management Mode
    - Programmable clock divider
    - Automatic hardware and software exit
■ Two full-duplex serial ports
■ Programmable watchdog timer
■ 13 interrupt sources (six external)
■ Five levels of interrupt priority
■ Power-fail reset
■ Early warning power-fail interrupt

APPLICATIONS
    Data Logging
    Vending
    Automotive Test Equipment
    Motor Control
    Magstripe Reader/Scanner
    Consumer Electronics
    Gaming Equipment
    Appliances (Washers, Microwaves, etc.)
    Telephones
    HVAC
    Building Security and Door Access Control
    Building Energy Control and Management
    Uninterruptible Power Supplies
    Programmable Logic Controllers
    Industrial Control and Automation