1394b specification released
MAY 22--The 1394 Trade Association (Santa Clara, CA; www.1394ta.org) has unveiled its new 1394b specification, the updated version of the electronics industry's multimedia bus. This specification supplements the original IEEE 1394-1995 and 1394a specifications and is expected to expand the adoption of the multimedia standard in new applications. The 1394 Trade Association includes more than 170 electronic-product manufacturers worldwide dedicated to the proliferation and enhancement of the IEEE 1394 standard.
The IEEE 1394 specification, also known as FireWire and iLink, is used to interface desktop and notebook computers, PC peripherals, and camcorders and digital cameras, among others. It also is being adopted for automotive, industrial, and instrumentation applications. The 1394b specification provides bandwidth, speed, distance, and cost-efficiency improvements over the original IEEE 1394-1995 specification. For example, it raises bus rates initially to 800 Mbits/s and 1.6 Gbits/s and then to 3.2 Gbits/s over plastic fiberoptic cables. The cable length of audio and video transfers over plastic fiber is extended to 50 m at 200 Mbits/s and to 100 m at 400 Mbits/s; over glass fiber, transfer rates increase to 3.2 Gbits/s. An efficient bus arbitration scheme, known as BOSS (Bus Owner Supervisor Selector), implements overlapped, pipelined arbitration, and the arbitration protocol can run in parallel with data transmissions. Hybrid bus operation enables backward compatibility with the IEEE 1394-1995 and 1394a specifications.
Costs of 1394b silicon and 1394b-enabled products are expected to be lower than products using earlier specification versions, according to Michael Johas Teener, chief technology officer at Zayante Inc. and one of the originators of the FireWire standard. Gate counts for 1394b ICs are anticipated to double to between 20,000 and 25,000. Analog designs should be simpler because the 1394b version uses unidirectional arbitration signaling instead of common-mode signaling, which improves efficiency and reduces voltages.
The introduction of 1394b results from more than 18 months of technical effort. The final specification is now in recirculation for approval by all members of the 1394b committee.
Says 1394 Trade Association chairman Max Bassler of Molex Inc., "The 1394b specification provides the bandwidth, distance, and overall performance to make it the ideal choice for home networking, industrial applications, and computer peripherals. It also is gaining momentum among leading vehicle manufacturers, who want to use it as the network bus for electronics in automobiles. We expect to see the first 800-Mbit/s devices this summer, and accelerated design activity by autumn."
Major serial-bus semiconductor suppliers including Texas Instruments Inc., NEC, Panasonic, and Agere are at work on 1394b devices. Omneon Video Networks has demonstrated a 300-m, 800-Mbit/s connection using multimode glass fiber, NEC has shown a plastic fiberoptic system, and Zayante has begun shipping 1394b silicon devices.