Microchip Technology, Inc. TMC2074

The TMC2074 network controller is CircLink technology's flagship product. The TMC2074'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. TMC2074 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. The TMC2074 has two operational modes: "Peripheral Mode" and "Standalone Mode". It can operate with or without the existence of a system CPU on a network node. In Peripheral Mode, the TMC2074 has 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 TMC2074 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 TMC2074 has 8-bit programmable I/O available. When operating in Standalone mode, the TMC2074's I/O configuration is16-bit. The TMC2074 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 Dual Operation Modes Peripheral (Host) Mode Operates with MCU Standalone (I/O) Mode Operates without MCU Supports 8 Bit Programmable General Purpose I/O at Peripheral Mode Supports 16 Bit Input and 16 Bit Output at Standalone Mode 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 128-Pin, VTQFP RoHS Compliant Package Temperature Range from 0 to 70 Degrees C