MicroVAX II

From: Eric Smith <eric_at_brouhaha.com>
Date: Wed Nov 27 10:07:01 2002

> As most (all?) current CPUs are to some extent or other superscalar, the
> concept of single-stepping is, in itself, not well defined for these
> processors.

Certainly it is. There are traditionally two kinds of single-stepping:

Single-clock-cycle (implemented in hardware): the processor does whatever
   it normally does on one one clock cycle every time you "press the
   button". A superscalar processor can do that just as well as any other
   processor, though it will typically be executing part or all of several
   instructions every time you give it a clock.

Single-instruction (can be hardware on some systems, but more commonly
   implemented in software): my debugger still does that just fine, even
   on the latest superscalar processors. I use it all the time. It would
   be pretty tough to debug software if one couldn't do that.
Received on Wed Nov 27 2002 - 10:07:01 GMT