On its website, Atmel boasts that its XMEGA line of microcontrollers support the KnX network:
http://www.atmel.com/applications/building_automation/comfort_control.asp?AppID=1041
http://www.atmel.com/applications/lighting/lighting_control.asp?AppID=2180
I downloaded several XMEGA datasheets and white papers, but I found no other references to KnX in them. And experience tells me that "if it is not explicitly stated in datasheet, then the product cannot do it". So is the KnX support true or is it just an Atmel marketing gimmick?
Now, I know that I can buy KnX library (it costs 1000 EUR, by the way) and compile it... but I can do this with any microcontroller, not just XMEGA.