COM20020ITQFP

Application Specific Microcontrollers Overview

The COM20020ITQFP is a 48-pin TQFP embedded ARCNET controller implementing the ANSI 878.1 token-passing protocol. It integrates a 2Kx8 dual-port RAM buffer and supports data rates up to 5 Mbps using an internal clock multiplier with a 20 MHz crystal. The device operates on a single +5V supply within an industrial temperature range of -40°C to +85°C. It features automatic detection of microcontroller interface types (80XX or 68XX) and includes flexible media interfaces for traditional hybrid or RS-485 connections.

Application Specific Microcontrollers Feature Summary

• ARCNET Protocol Engine: Supports deterministic token-passing communication compliant with ANSI 878.1, handling network reconfiguration automatically.
• Integrated Memory: Contains 2Kx8 on-chip dual-port RAM organized into eight 256-byte pages for packet queuing and scratch-pad memory.
• Flexible Interface: Automatically detects and adapts to 80XX-like or 68XX-like microcontroller buses without external glue logic.
• Media Options: Supports traditional dipulse signaling for long distances or RS-485 differential driver interfaces for low power and reliability.

Application Specific Microcontrollers Applications

• Industrial automation systems requiring deterministic real-time control
• Factory and building automation networks
• Transportation applications utilizing ARCNET protocols

Application Specific Microcontrollers Procurement Notes

Verify that the specific orderable part number corresponds to the 48-pin Thin Quad Flat Package (TQFP) variant. Confirm the silicon revision matches the required documentation level, as errata sheets may exist for specific revisions. Ensure the application environment stays within the specified -40°C to +85°C operating temperature range.

Application Specific Microcontrollers Selection Notes

Select this component when a dedicated hardware solution for ARCNET networking is required to offload protocol processing from the main CPU. It is suitable for designs needing support for up to 255 nodes and various topologies like star, tree, or bus. Ensure the host microcontroller can provide the necessary address and data bus signals for the detected interface mode.

Application Specific Microcontrollers Part Context

This component belongs to the COM20020iD family of embedded ARCNET controllers manufactured by Microchip Technology. It is designed to replace discrete logic solutions for ARCNET implementation, offering a compact footprint and integrated memory to simplify system design for embedded control environments.

Application Specific Microcontrollers Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Designers should consult Microchip technical support for current equivalent products or next-generation replacements if discontinuation occurs.

Application Specific Microcontrollers FAQ

How does the COM20020ITQFP determine the microcontroller interface type?

Upon hardware reset, the device performs a software-initiated sequence involving write and read accesses to determine if the bus uses separate Read/Write signals (80XX-like) or Direction/Data Strobe signals (68XX-like). It also checks for multiplexed versus non-multiplexed address/data buses.

What is the maximum data rate supported by this controller?

The controller supports data rates ranging from 156.25 Kbps to 5 Mbps. Achieving the 5 Mbps rate requires an external 20 MHz crystal oscillator and configuration of the internal clock multiplier via the Setup2 register.

How is network reconfiguration handled?

The device automatically handles network reconfiguration by sending a Reconfigure Burst to terminate all activity when a new node activates or if the token is lost. It then initiates an Invitation to Transmit sequence to establish the token passing order among active nodes.