This document describes the features and characteristics of a high-speed microcontroller, including 80C52 compatibility, 8051 pin and instruction set compatibility, four 8-bit I/O ports, three 16-bit timer/counters, 256 bytes of scratchpad RAM, etc.
The Maxim DS87C520 and DS83C520 are 8051‑compatible high‑speed microcontrollers offering up to 33 MHz clock rates, 16 kB of on‑chip ROM, 1 kB of SRAM and a 256‑byte scratchpad. They include four 8‑bit I/O ports, three 16‑bit timers, two full‑duplex serial ports, and a programmable power‑management mode.
The document provides detailed ordering information, pin descriptions, special function registers, memory map, timing diagrams, package outlines and revision history, enabling designers to integrate the devices into embedded applications.
| Program memory size | 16 kB |
|---|---|
| Extra on‑chip SRAM | 1 kB |
| Scratchpad RAM | 256 Bytes |
| I/O ports | Four 8‑bit ports |
| Timer/Counters | Three 16‑bit |
| Serial ports | Two full‑duplex hardware ports |
| Interrupt sources | 13 |
| Power‑management mode | Programmable clock source (crystal/64 or crystal/1024) |
They are offered in 40‑pin PDIP, 44‑pin PLCC, 44‑pin TQFP and 40‑pin windowed CERDIP packages.
The microcontroller includes two full‑duplex hardware serial ports.
Up to 16 kB of on‑chip ROM is available, selectable via the ROMSIZE register.