This example shows the USB BUS data structure for the EHAO High speed
   controller.

 OpenVMS system analyzer

 SDA> usb set con eha0
 Controller set to EHA0
 SDA> usb show bus
 Bus address is:                 89731750
 Structure type is               00000001
 Spinlock is                     0000003a
 Bus number is                   00000003
 Host controller UCB address is  89604380
 Flags 1 -> default addr in use  00000000
 Switch table address is         89722400
 Callback thread Queue Flink     89731768
 Callback thread Queue Blink     89731768
 Thread state is
 USBD_THREAD_IDLE
 Outstanding thread count        00000000
 KPB address                     89731980
 Skipping fork block
 Fork state 0 - idle 1 - bsy     00000000
 Root hub address                89749590
 Callback thread Queue Flink     897317b8
 Callback thread Queue Blink     897317b8
 Thread state is
 USBD_THREAD_IDLE
 Hub thread KPB                  89731840
 Wait Q flink                    897317c8
 Wait Q blink                    897317c8
 Array descriptor for the root hub
 Array size                      00002ed0
 Array location                  896ee0d0
 Available entries flink         89755290
 Available entries blink         89755290
 Used entries flink              89746690
 Used entries blink              89750e50
 Count of available entreis      00000001
 Count of used entries           00000004
 Number to add if expanding      00000001
 SDA>