Oxford Semiconductor has introduced a new bridge chip which is said to dramatically simplify implementation of external hard disk and optical disk drives for both PC and Mac platforms. In its 128-lead QFP package, the OXU921S features an integral SATA Phy, USB2.0 PHY and ARM7TDMI processor. The USB mass storage device firmware provided with the chip ensures its full compatibility with standard operating system drivers.

The bridge chip's embedded USB2.0 Link and Phy support full and high-speed modes and offer backwards compatibility with USB1.1. The OXU921S has a 6-Kbyte cache for USB data, facilitating a data transmission speed up to 480Mbps. The integrated SATA core and PHY operate at 1.5GHz, resulting in a disk interface data rate of 150 Mbytes/s.

The use of an ARM7 processor, with 8-Kbyte close coupled RAM, means users are free to create highly differentiated external SATA drive enclosures through custom firmware development. 12 GPIOs further extend the device's capability. An embedded UART is provided for use in code development and debug and firmware can be programmed through the USB port to help simplify manufacturing and in-field updates.

To optimize the firmware development process, the OXU921S shares a common software base with other Oxford Semiconductor devices and is backed by a full development kit and evaluation board. The OXU921S is available for sub US$5.5 in 100,000 quantities.