New bridge chip gives data storage manufacturers fast, low-cost way into FireWire (IEEE 1394) connectivity

The OXFW900 is a high performance native bridge chip for providing ATA/ATAPI (IDE) peripherals with FireWire (IEEE 1394-1995) connectivity. With the integrated Serial Bus Protocol (SBP-2), it can use generic device drivers available in the Microsoft Windows and Apple MacOS operating systems. This makes it ideal for smart cable or tailgate interface applications in removable media drives, CD-ROM, CD-R, CD-RW, DVD and hard disk drives. Manufacturers of these peripherals can quickly and reliably produce plug-and-play FireWire versions of their products to meet fast-growing demand for such devices. Using the OXFW900 introduces no bottleneck to the data flow, minimises R&D expenditure and reduces time-to-market.

A three-chip solution using the new device requires only the addition of an external 1394 PHY and ROM. A slow 32K x 8 external OTP or FLASH ROM is sufficient for most applications. For applications that need sustained data transfer rates in excess of 10 Mbytes/s, a 16-bit, 70nS ROM is recommended. The OXFW900 supports the standard IEEE 1394-1995 PHY-LINK interface and the sustained IDE data transfer rate is 25Mbps, faster than today's highest performance disk drives demand.

The 1394 transaction layer and SBP-2 protocol are implemented using a combination of ARM7TDMI 32-bit RISC processor and an Operational Request Block (ORB) hardware co-processor with a high performance buffer manager.

The buffer manager has a RAM bandwidth of 800Mbps. It provides storage for 1394 and ATA/ATAPI packets, automatically storing them and passing them to the appropriate destinations without any intervention from the processor.

The OXFW900 uses low power CMOS technology. It comes in a 128-pin TQFP package.

The device costs $12 (US) in 10,000+ quantities and is available in volume now.