DETAILED DESCRIPTION
The DS87C530/DS83C530 EPROM/ROM microcontrollers with a real-time clock (RTC) are 8051- compatible microcontrollers based on the Dallas Semiconductor high-speed core. They use 4 clocks per instruction cycle instead of the 12 used by the standard 8051. They also provide a unique mix of peripherals not widely available on other processors. They include an on-chip RTC and battery backup support for an on-chip 1k x 8 SRAM. The new Power Management Mode allows software to select reduced power operation while still processing.

FEATURES
■ 80C52 Compatible
    8051 Instruction-Set Compatible
    Four 8-Bit I/O Ports
    Three 16-Bit Timer/Counters
    256 Bytes Scratchpad RAM
■ Large On-Chip Memory
    16kB EPROM (OTP)
    1kB Extra On-Chip SRAM for MOVX
■ ROMSIZE Features
    Selects Effective On-Chip ROM Size from
        0 to 16kB
    Allows Access to Entire External Memory Map
    Dynamically Adjustable by Software
    Useful as Boot Block for External Flash
■ Nonvolatile Functions
    On-Chip Real-Time Clock with Alarm Interrupt
    Battery Backup Support of 1kB SRAM
■ High-Speed Architecture
    4 Clocks/Machine Cycle (8051 = 12)
    Runs DC to 33MHz Clock Rates
    Single-Cycle Instruction in 121ns
    Dual Data Pointer
    Optional Variable Length MOVX to Access
        Fast/Slow RAM /Peripherals
■ Power Management Mode
    Programmable Clock Source Saves Power
    Runs from (crystal/64) or (crystal/1024)
    Provides Automatic Hardware and Software Exit
■ EMI Reduction Mode Disables ALE
■ Two Full-Duplex Hardware Serial Ports
■ High Integration Controller Includes:
    Power-Fail Reset
    Early-Warning Power-Fail Interrupt
    Programmable Watchdog Timer
■ 14 Total Interrupt Sources with Six External