19 Mar
2010
19 Mar
'10
12:51 p.m.
Sorry to barge in, but I don't think is exactly
correct. On most ARM
systems these days, for
example, there are multiple hardware breakpoints inside the jtag debug
logic which are
not intrusive. They don't perterb the instruction stream at all until
they are hit.
No, you misunderstood me. A breakpoint is intrusive in that when it is
hit it stps the code execution (There are plenty of other debugging
feautrs in some chip,s but they're not strictly breakpoints). For tyhe
sort of thing I would use a microcontroller for (which involves
generating precisely timed signals to control external hardware) I can't
have my progrma suddenly being stopped for the debugger.
A logic analyser will grabe state and not stop the program running.
And, on some ARM SOC's there is an internal trace
buffer which is also
not intrusive,
and is "free" in terms of timing (i.e. it doesn't slow anything down).
Both have saved me a few times.
Do any of these processors have the debugging commands _to the chip_ 100%
docuemtned so that I could write my own debugging software to run on
$classic_computer? THe PCs don't appear to...
-tony