USB 3.0 Creeps Closer

Intel has released a new set of tools that will allow hardware vendors to build chips for the upcoming version of the USB(Universal Serial Bus) interface. The Extension Host Controller Interface(xHCI) draft specification allows the USB host controllers to communicate with a software stack, allowing developers to communicate with the USB 3.0 hardware and build controller chips for devices.



USB 3.0 is targeted at ten times the current bitrate, reaching roughly 4.8 Gb/s (600MB/s) by utilizing two additional high-speed differential pairs for "Superspeed" mode at a clock frequency of 2.5GHz, and with the possibility for optical interconnect. The two new differential pairs make the cable about as thick as an ethernet cable and provide full-duplex transfers. The USB 3.0 specification was 90% complete as of August 13, 2008 and commercial products are expected to arrive in 2009 or 2010. USB 3.0 is designed to be backwards-compatible with both USB 2.0 and USB 1.1 and employs more efficient protocols such as 8b/10b encoding to conserve power while increasing the maximum power available for connected devices.



Intel describes the interface as a simplified kit for integrating the the "SuperSpeed" USB connections. Intel is hoping to push USB 3.0 as the connection standard for the HD media devices that demand larger pipelines for data transfers. The company counts Microsoft, AMD, Dell, and nVidia among the early backers for SuperSpeed USB. Intel hopes to release the next xHCI draft specification by the end of the year.