Motorola MVME166IG 用户手册

Using the 166Bug Debugger

4-6

In commands with RANGE specified as ADDR DEL ADDR,
and with size option W or L chosen, data at the second
(ending) address is acted on only if the second address is a
proper boundary for a word or longword, respectively.

Eight pseudo-registers (R0 through R7) called offset registers are used to 
simplify the debugging of relocatable and position-independent modules.  
The listing files in these types of programs usually start at an address 
(normally 0) that is not the one at which they are loaded, so it is harder to 
correlate addresses in the listing with addresses in the loaded program.  The 
offset registers solve this problem by taking into account this difference and 
forcing the display of addresses in a relative address+offset format.  Offset 
registers have adjustable ranges and may even have overlapping ranges.  The 
range for each offset register is set by two addresses:  base and top.  Specifying 
the base and top addresses for an offset register sets its range.  In the event that 
an address falls in two or more offset registers’ ranges, the one that yields the 
least offset is chosen.