GENERAL DESCRIPTION
SMSCs COM20019I is a member of the family of Embedded ARCNET Controllers from Standard Microsystems Corporation. The device is a general purpose communications controller for networking microcontrollers and intelligent peripherals in industrial, automotive, and embedded control environments using an ARCNET protocol engine. The flexible microcontroller and media interfaces, eight- page message support, and extended temperature range of the COM20019I make it the only true network controller optimized for use in industrial, embedded, and automotive applications.

Product Features
■ New Features:
■  − Data Rates up to 312.5 Kbps
■  − Programmable Reconfiguration Times
■ 28 Pin PLCC and 48 Pin TQFP Packages; Green, Lead-free Packages also Available
■ Ideal for Industrial/Factory/Building Automation and Transportation Applications
■ Deterministic, (ANSI 878.1), Token Passing ARCNET Protocol
■ Minimal Microcontroller and Media Interface Logic Required
■ Flexible Interface For Use With All Microcontrollers or Microprocessors
■ Automatically Detects Type of Microcontroller Interface
■ 2Kx8 On-Chip Dual Port RAM
■ Command Chaining for Packet Queuing
■ Sequential Access to Internal RAM
■ Software Programmable Node ID
■ Eight, 256 Byte Pages Allow Four Pages TX and RX Plus Scratch-Pad Memory
■ Next ID Readable
■ Internal Clock Scaler for Adjusting Network Speed
■ Operating Temperature Range of -40oC to +85oC
■ Self-Reconfiguration Protocol
■ Supports up to 255 Nodes
■ Supports Various Network Topologies (Star, Tree, Bus...)
■ CMOS, Single +5V Supply
■ Duplicate Node ID Detection
■ Powerful Diagnostics
■ Receive All Packets Mode
■ Flexible Media Interface:
   − RS485 Differential Driver Interface For Low Cost, Low Power, High Reliability