Supply original DS87C520-ECL+, Embedded - Microcontrollers, by Maxim Integrated

The DS87C520/DS83C520 EPROM/ROM high-speed microcontrollers are fast 8051-compatible microcontrollers.
They feature a redesigned processor core without wasted clock and memory cycles. As a result, the devices execute every 8051 instruction between 1.5 and 3 times faster than the original for the same crystal speed. Typical applications will see a speed improvement of 2.5 times using the same code and the same crystal.
The DS87C520/DS83C520 offer a maximum crystal speed of 33MHz, resulting in apparent execution speeds of 82.5MHz (approximately 2.5X).
FEATURES
• 80C52 Compatible 8051 Pin- and Instruction-Set Compatible Four 8-Bit I/O Ports Three 16-Bit Timer/Counters 256 Bytes Scratchpad RAM
• Large On-Chip Memory 16kB Program Memory 1kB Extra On-Chip SRAM for MOVX
• ROMSIZE Feature Selects Internal ROM Size from 0 to 16kB Allows Access to Entire External Memory Map Dynamically Adjustable by Software Useful as Boot Block for External Flash
• 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 to Save Power CPU 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
• 13 Interrupt Sources with Six External
• Available in 40-pin PDIP, 44-Pin PLCC, 44-Pin TQFP, and 40-Pin Windowed CERDIP
• Factory Mask DS83C520 or EPROM (OTP) DS87C520