Intel this morning made available the updated Extended Host Controller Interface (xHCI) specification that will allow manufacturers to start work on USB 3.0 devices.

The xHCI spec describes the register-level host controller interface for USB 2.0 and above. As you may know, the host controller connects the computer with external peripherals, and the host controller interface allows the operating system to communicate with the controller. Intel is making the xHCI spec available under RAND-Z (Reasonable and Non-discriminatory licensing with zero royalties) terms today to companies that have signed the xHCI contributor agreement.

In June, an unnamed AMD source publicly expressed discontent with Intel's progress on the USB 3.0 spec, and said AMD was actually working on an alternate specification, since the USB 3.0 architecture is not yet standard. Prototype devices developed by Intel, shown at last year's Intel Developer's Forum, exhibit transfer speeds of up to 4.8 Gbps. (Intel's next US-based IDF is just next week.)

In October, IEEE expects FireWire 3200 (IEEE 1394-2008) products to come to market. While a completed USB 3.0 specification isn't expected until sometime in 2009, next year will put us at the threshold of the new generation of wired connections.