Hi,

Can someone give me some explanation (or the pointer to explanation)
on the following  :


How does one debug code which is running on a target board processor
using a debugger running on a PC or workstation (so running on
a different processor). 
How is synchronized on breakpoints, how is single stepped ...
Does the debugger have knowledge about the target processor
instructions ?
Are there standardizations needed and/or common ? Can each debugger
be used for each processor ? If not, by what it is determined ?

Seems I need really some light in my darkness here. Although I'm
familiar with software and with hardware, I don't see the combination
here.

Thanks in advance.