The TMC2072 network controller is CircLink technology's flagship product. The TMC2072's flexibility and rich feature set enable a high-reliability and high-performance, real-time and control-oriented network without the cumbersome middle layer protocol stacks and complex packet prioritization schemes typically required.

TMC2072 operates at network data transfer rates up to 5 Mbps. Its embedded 1 kByte RAM can be configured into a maximum of 32 pages to implement a 31-node network where each node in the network has the same local memory.

TMC2072 supports "Peripheral Mode" operation, which includes two selectable communication modes:"Free Format Mode" and "Remote Buffer Mode". Free Format mode, retained from ARCNET, is "packet oriented" communication. Remote Buffer mode communication is a CircLink-specific feature, and is a token oriented communication, which includes automatic data transmission when the token arrives.

The TMC2072 has a flexible 8-bit or 16-bit databus to interface various CPU types including X86, 68XX, and SHx with multiplexed or non-multiplexed address/data. When operating in Peripheral mode, the TMC2072 has 8-bit programmable I/O available. When operating in Standalone mode, the TMC2072's I/O configuration is16-bit. The TMC2072 also integrates a 3-port hub (two ports for external connection) to accommodate various network topologies (Bus, Star, etc.) and combinations.

Additional Features

Features
• Low Power CMOS, 3.3 Volt Power Supply with 5 Volt Tolerant I/O
• Supports 8/16-Bit Data Bus
• Both 86xx and 68hxx Platforms
• 1K On-chip Dual Port Buffer Memory
• Sequential I/O Mapped Access
• Enhanced Token Passing Protocol from ARCNET
• Maximum 31 Nodes per Network
• Token Retry Mechanism
• Maximum 256 Bytes per Packet
• Consecutive Node ID Assignment
• Memory Mirror
• Shared Memory within Network
• Network Standard Time
• Network Time Synchronization
• Automatic Time Stamping
• Coded Mark Inversion
• Intelligent 1-Bit Error Correction
• Magnetic Saturation Prevention
• Single Operation Mode
• Supports Only Peripheral (Host) Mode Operates with MCU
• Supports 8 Bit Programmable General Purpose I/O
• Dual Communication Modes (with Peripheral Mode)
• Free Format Mode
• Remote Buffer Mode
• 3 Port Hub Integrated
• 1 Internal and 2 External
• Flexible Topologies
• Bus, Star, and Tree
• Low-Cost Media can be Used
• RS485 Differential Driver
• Fiber Optics and Twisted Pair Cable Supported
• 100-Pin, TQFP RoHS Compliant Package
• Temperature Range from 0 to 70 Degrees C