GENERAL DESCRIPTION
SMSC's COM20020-5 is a member of the family of Industrial Network Controllers from Standard
Microsystems Corporation. The device is a special purpose communications controller for networking microcontrollers and intelligent peripherals in industrial, automotive, and embedded control environments using an ARCNET® protocol engine. The small 24-pin package, flexible microcontroller and media
interfaces, eight-page message support, and extended temperature range of the COM20020-5 make it the only true network controller optimized for use in industrial and automotive applications. Using an ARCNET protocol engine is the ideal solution for factory automation applications because it provides a
token-passing protocol, a highly reliable and proven networking scheme, and a data rate of up to 5 Mbps when using the COM20020-5.

FEATURES
· 24-Pin Embedded Network Controller/Transceiver/RAM
· Ideal for Industrial/Factory Automation and Automotive Applications
· Deterministic, 5 Mbps, Token Passing ARCNET Protocol
· Minimal Microcontroller and Media Interfaces
· Flexible Microcontroller Interface for Use with 80XX, 68XX, etc.
· Automatically Detects Type of Microcontroller Interface:
  -Non-Multiplexed or Multiplexed Bus
  -Separate nRD & nWR Lines or DIR & nDS Lines
· Full 2Kx8 On-Chip RAM
· Command Chaining for Top Performance
· Reduced Reconfiguration Times
· Sequential Access to Internal RAM
· Software Programmable Node ID
· Duplicate Node ID Detection
· Powerful Diagnostics
· Receive All Mode
· Data Rates from 5 Mbps to 312.5 Kbps
· 24-Pin DIP or 28-Pin PLCC Package
· Flexible Media Interface:
  - RS485 Differential Driver Interface for Low Cost, Low Power, High Reliability
- Backplane Mode for Direct Connection to Media in Short Distance Applications
· Eight, 256-Byte Pages Allow 4 Pages TX and RX Plus Scratch-Pad Memory
· No Wait-State Arbitration
· Programmable TXEN Polarity
· Next ID Readable
· Internal Clock Prescaler for Slower Network Speed without Slowing Arbitration
· Operating Temperature Range of -40^oC to +85^oC
· Self-Reconfiguring Protocol
· Supports up to 255 Nodes
· Supports Various Network Topologies (Star, Tree, Bus...)
· CMOS, Single +5V Supply