Intel heeft een universele specificatie van de USB 2.0 host interface vrijgegeven. Hiermee kunnen bedrijven als Microsoft, Apple, Red Hat, Sun en andere OS makers USB 2.0 host controller support in hun OS inbouwen. De specificatie is vrijelijk te verkrijgen specificeert in essentie hoe een USB controller met het OS praat:
The new spec., called the Enhanced Host Controller Interface (EHCI), unifies the two alternative host controller interfaces developed with USB 1.0 and 1.1, which should simply OS' support for the connectivity standard. EHCI is compatible with USB 1.1 devices and hubs, even going so far as to work with existing device drivers.
That's done by supporting what Chipzilla calls USB 1.1 companion controllers, which leave the main USB 2.0 controller free to handle high-speed - ie. 400Mbps - bus traffic. That sounds suspiciously like a clever way of selling otherwise redundant USB 1.1 controller chips alongside the more up-to-date USB 2.0 versions.
And "the architecture is also highly optimised, and therefore consumes minimum CPU overhead - less than the amount that a USB 1.1 UHCI host controller consumes", Intel claims. The next stage is to release compliance testing procedures, which will be released in the first half of next year, according to Intel. After that, it will publish the final version of EHCI. ®