Table 2-1. Default Segment Register Selection Rules

Memory Reference Needed  Segment     Implicit Segment Selection Rule
  or Register Used

Instructions             Code (CS)   Automatic with instruction prefetch

Stack                    Stack (SS)  All stack pushes and pops. Any
					memory reference that uses ESP or
					EBP as a base register.

Local Data               Data (DS)   All data references except when
					relative to stack or string
					destination.


Destination Strings      Extra (ES)  Destination of string instructions.
						




## these all can be pointed at the same segment, or 0. They are when
the chip boots, which may need some handling for SS. See also: SS
at IML.


Only in
   the following special cases is there an implied segment selection that a segment
   prefix cannot override:
     * The use of ES for destination strings in string instructions.
     * The use of SS in stack instructions.
     * The use of CS for instruction fetches.
