IEEE 1394 Switch LSI for Home Networks

NEC Corporation has developed the world’s first prototype switch LSI for the IEEE 1394 high-speed serial bus standard, which is expected to form the backbone of near future home networks. The switch LSI provides hardware routing of data traffic and comes with a firmware library enabling automatic network configuration, enhanced data transfer rates for early IEEE 1394devices as well as optimised data transfer over wireless and optical media.

With the increasing digitalisation of audio-visual products and increasing amounts of video and audio data traffic across networks, there is a greater need for a high-speed network standard for the home, a role for which IEEE 1394 is being seen as a candidate. The standard offers data transfer speeds of between 100-400 megabits per second (Mbps) with full Plug ‘n Play capability, and it can lever the increasing number of personal computers and digital electronics now being offered with IEEE 1394 connectivity.

The prototype 2-port switch LSI conforms to the IEEE P1394.1 bridge specifications and utilises NEC’s original network clock synchronisation technology. It provides hardware packet routing between two IEEE1394 buses with the equivalent throughput to a full IEEE1394 bus, while maintaining full compatibility with legacy IEEE1394 devices.

The prototype LSI also has a firmware library that boosts slower data transfer rates, such as with products like legacy 100Mbps digital video camcorders, to enable data transfer rates of up to 400Mbps. In addition, the firmware provides automatic network configuration functionality to enable large-scale IEEE1394 networks with multiple switches.

An important feature of the prototype LSI is its ability to overcome both the bus reset, which occurs when new devices are connected to a network and that can interfere with data transfers, and the limit of 63 device IDs per IEEE1394 bus.

Another ability the firmware provides for the prototype, is the use of wireless media for IEEE1394 in the 2.4 gigahertz (GHz) and 5GHz bands, and use of the LSI as a relay for long distance IEEE1394 communications over optical fiber to enable transmissions over distances of 1 kilometer or greater.

The prototype bridge LSI also has a V850 32-bit central processor unit (CPU) core running at a maximum 50MHz and random access memory (RAM) with an external memory interface, in a 176-pin plastic quad flat package (QFP) operating at 3.3 and 2.5 volts.

NEC is now working on development of products based on the prototype development and expects to realise them early in 2001. The company also expects to introduce various technologies from this prototype project in other related products.

This work was partly supported by the Telecommunications Advancement Organisation of Japan.

On the web at www.nec.co.jp