GENERAL DESCRIPTION
The COM20051+ is a low-cost, highly-integrated microcontroller incorporating a highperformance network controller based on the ARCNET Token Bus Standard (ANSI 878.1). The COM20051+ is based around the popular Intel 8051 architecture. The device is implemented using a microcontroller core similar to the Intel 80C32 ROMless version of the 8051 architecture. The COM20051+ is ideal for distributed control networking applications such as those found in industrial/machine controls, building/factory automation, consumer products, instrumentation, and automobiles.

FEATURES
• Low Cost
• Microcontroller Based on Popular 8051 Architecture
• Intel 8051 Code Compatible
• 68 Pin PLCC
• Network Supports up to 255 Nodes
• Powerful Network Diagnostics
• Maximum 512 Byte Packets
• Duplicate Node ID Detection
• Self-Configuring Network Protocol
• Retains all 8051 Peripherals Including Serial I/O and Two Timers
• Utilizes ARCNET® Token Bus Network Engine
• Requires No Special Emulators
• 5 Mbps to 156 Kbps Network Data Rate
• Network Interface Supports RS-485, Twisted Pair, Coaxial, and Fiber Optic Interfaces
• Receive All Mode Allows Any Packet to Be Received
• On-Board Programmable Watchdog Timer
• Analog Data Acquisition Port
   - Interfaces to Any A/D Converter up to 16 Bits Wide
   - Sampling Rates from 1 s to 100ms Possible
   - Decouples 80C32 from Repetitive Sampling Tasks