FireWire 800 heralds the future of home networking

The prospect of a ubiquitous standard for interconnecting audio and AV devices in the home has come one step closer with the arrival of a digital audio amplifier system based on the FireWire 800 (IEEE 1394b) serial bus and IEC61883-6 protocol for audio and music data transmission.

Using an audio reference design from Oxford Semiconductor for its OXUF922 IDE/IEEE 1394b programmable bridge chip, the system demonstrated for the first time by Apple at the MacWorld exhibition achieves the high quality, auto-configuration and interoperability long promised by digital audio networks.

Supporting transfer speeds up to 800Mbps and a network length of 100m, an IEEE 1394b bus provides a usable cabling standard for the home and the bandwidth to deliver close-range, super high-speed data exchange. Apple has supported the IEC61883-6 audio protocol over an IEEE 1394 bridge since OSX V10.0.

The digital audio system features the OXUF922 development board with a Wolfson DAC expansion board mounted on a prototyping header. The unit is connected to an Apple MAC over an IEEE 1394 serial bus using the IEC61883-6 transmission protocol.

The OXUF922 receives isochronous audio packets from the Apple MAC, handles buffer management, audio and sample rate control and passes the packets to the DAC. Mounting the unit in a surround sound amplifier system for example, brings out the full clarity of the digital audio in a home environment.

Significantly for home networks and local MAC/PC speaker systems the power available on the bus is relatively high - 45W in power class 2, allowing hi-fi sound at hi-fi volumes. As a result, devices are able to interconnect and use bus power without the need for separate power supplies.

Andy Thorne, Applications Manager at Oxford Semiconductor commented, "The announcement means that consumers can have a high quality, high power MAC or PC digital speaker system on their desks without the inconvenience of external power supplies. Right now the system works with a standard MAC, both follow the IEC61883-6 standard and no special drivers are required."

Since IEEE 1394b supports up to 63 daisy-chained devices, plug-and-play operation, hundreds of digital channels and allows combinations of audio/video/IP data/control signals to be handled automatically, the standard will enable far more sophisticated digital AV connections that distribute high quality audio data and power around a large network of integrated amplifier/speaker devices.