The HomePlug 1.0-compliant Piranha two-chip set from Cogency comprises the company's CS1100 media-access-controller/physical-layer chip and Analog Devices' (www.analog.com) AD9875 broadband-modem, mixed-signal, front-end IC. The HomePlug 1.0 specification, which the HomePlug Powerline Alliance released in June 2001, enables vendors to build networking components that allow you to create an Ethernet-class network in your home using existing wiring (see "Specification allows ac-line wiring to do double duty," EDN, July 19, 2001, pg 24). The physical layer uses orthogonal frequency-division multiplexing among 76 carriers in the 4.5- to 21-MHz band to achieve a raw data rate as high as 14 Mbps. The HomePlug media-access-controller layer supports video and audio data with quality-of-service priority classes; 56-bit DES encryption ensures privacy.

You can configure the CS1100's host interface to operate as an IEEE 802.3u media-independent interface or a general-purpose, 8-bit CPU-bus interface. Using the media-independent interface allows you to connect the CS1100 to an Ethernet media-access controller. Cogency has embedded a 150-MHz ARM7TDMI processor into the CS1100 Piranha media-access controller, and you can upgrade the firmware in the field. A simple Piranha-based device requires the addition of an optional EEPROM, a 25-MHz crystal, transmit and receive filters, a transmit driver, and a power-line coupler. The CS1100 comes in a 100-pin LQFP and operates at 3.3V for I/O and 1.8V for core power supplies. The AD9875 operates from 3.3V and is available in a 48-pin LQFP. Cogency expects to ship the $23 (25,000) Piranha chip set in large volumes during this quarter. You may also purchase an evaluation kit comprising two evaluation boards, Microsoft Windows drivers, and software tools for $5000.

Cogency Semiconductor, 1-416-217-0250, www.cogency.com.

HomePlug Powerline Alliance, www.homeplug.org.