ARCNET 3.3-V Controller IC Supports Operation At Industrial Temperatures

Aug. 7, 2000

Handling data rates up to 5 Mbits/s, the COM20020 ARCNET CMOS controller IC runs off 3.3-V supplies at −40°C to 85°C. This general-purpose communications IC for networking microcontrollers and intelligent peripherals can be used in...

Roger Allan

The device boasts eight-message support, programmable reconfiguration times, and a self-configuring protocol. The ARCNET protocol provides deterministic token-passing performance according to the ANSI 878.1 specification. Additionally, the IC requires minimal microcontroller and media-interface logic, while its flexible interface targets all microprocessors and microcontrollers.

The COM20020 doesn't blindly interface with controllers. Instead, it automatically identifies their types and responds accordingly. It also features a 2k by 8-bit dual-port RAM, command chaining for packet queuing, sequential access to internal RAM, and a software-programmable node ID. Eight 256-byte pages are on-chip as well. A scratch-pad memory lets users transmit and receive four pages. Network speed is adjustable via an internal clock scaler and multiplier.

This IC supports up to 255 nodes. Various network topologies, such as stars, trees, and buses, are all supported. The chip even sports duplicate-node ID detection, powerful diagnostics, and a flexible media interface. This interface comes with a traditional hybrid interface for distances up to four miles at 2.5 Mbits/s, along with an RS-485 differential interface for low-cost, low-power, and high-reliability interfacing.

The COM20020 is available in a 24-pin DIP or 28-pin PLCC. It costs $11 in 10,000-unit quantities. Delivery is within 12 to 16 weeks.

Standard Microsystems Corp., 80 Arkay Dr., P.O. Box 18047, Hauppauge, NY 11788-8847; (516) 435-6000; www.smsc.com.

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About the Author

Roger Allan

Roger Allan is an electronics journalism veteran, and served as Electronic Design's Executive Editor for 15 of those years. He has covered just about every technology beat from semiconductors, components, packaging and power devices, to communications, test and measurement, automotive electronics, robotics, medical electronics, military electronics, robotics, and industrial electronics. His specialties include MEMS and nanoelectronics technologies. He is a contributor to the McGraw Hill Annual Encyclopedia of Science and Technology. He is also a Life Senior Member of the IEEE and holds a BSEE from New York University's School of Engineering and Science. Roger has worked for major electronics magazines besides Electronic Design, including the IEEE Spectrum, Electronics, EDN, Electronic Products, and the British New Scientist. He also has working experience in the electronics industry as a design engineer in filters, power supplies and control systems.

After his retirement from Electronic Design Magazine, He has been extensively contributing articles for Penton’s Electronic Design, Power Electronics Technology, Energy Efficiency and Technology (EE&T) and Microwaves RF Magazine, covering all of the aforementioned electronics segments as well as energy efficiency, harvesting and related technologies. He has also contributed articles to other electronics technology magazines worldwide.

He is a “jack of all trades and a master in leading-edge technologies” like MEMS, nanolectronics, autonomous vehicles, artificial intelligence, military electronics, biometrics, implantable medical devices, and energy harvesting and related technologies.