Enable event tracing using the tracing capability in SDA.  You must load
   and start tracing in order for this command to become effective.

   Format

      USB SET UHCI TRACE parameter

1  –  Parameter

 event-mask:

   This hex number is a mask of all the events to be enabled.  The
   following events are defined.

         0x1       - Trace Control request start
         0x2 	  - Trace Interrupt start
         0x4	  - Bulk request start
         0x8 	  - Queue request on controller
         0x10	  - Set toggles
         0x20	  - Complete TD's
         0x40 	  - All controller interrupts
         0x80 	  - Normal completion
         0x100 	  - Error interrupts
         0x200 	  - Bit stuffing error
         0x400	  - CRC error
         0x800	  - Timeout errors
         0x1000	  - Babble errors
         0x2000	  - Data unerrun/overrrun
         0x4000    - Stall events
         0x8000	  - Poller timer tick all events
         0x10000   - Port 1 timer tick data
         0x20000	  - Port 1 changes reported to hubdriver
         0x40000	  - Port 2 timer tick data
         0x80000   - Port 2 changes reported to hubdriver
         0x100000  - Port reset start
         0x200000  - Port reset timeout
         0x400000  - Port reset wait for CSC

2  –  Example

   This example shows enabling tracing for queueing control request
   to the UHA0 controller.

 SDA> usb set con uha
 Controller set to UHA
 SDA> usb set uhci trace 1
 Tracing code not enabled