This example shows that we have a high speed hub attached to the
    EHA0 high speed controller, and that the high speed hub has a low speed
    function with two interfaces.

 OpenVMS system analyzer

 SDA> usb set con eha0
 Controller set to EHA0
 SDA> usb sho top
 --------------- TIER[0] ---------------
 Root HUB            address is 89749590
 --------------- TIER[1] ---------------
 High Speed HUB      address is 8974ded0
 --------------- TIER[2] ---------------
 Low Speed Function  address is 89750e50
       Interface Address: 89758ED0 UCB: 8975A780 Driver Name: SYS$KBDDRIVER
       Interface Address: 89759010 UCB: 8975E800 Driver Name: SYS$MOUDRIVER
 SDA>