User`s manual

96 digi.com Debugging with Dynamic C
6.3.3 Single Stepping
Single stepping has always been available in Dynamic C. In version 7.10, the ability to single step on C
statements with the Assembly window open was added.
Pros Single stepping allows you to closely supervise program execution at the source
code level, either by C statement or assembly statement. This helps in tracing the
logic of the program. You can single step any debuggable statement. Even Dy-
namic C library functions can be stepped into as long as they are not flagged as
not available with the keyword nodebug.
Cons Single stepping is of limited use if interaction with an external device is being
examined; an external device does not stop whatever it is doing just because the
execution of the application has been restrained.
Also, single stepping can be very tedious if stepping through many instructions.
Well-placed breakpoints might serve you better.
Uses Single stepping is typically used when you have isolated the problem and have
stopped at the area of interest using a breakpoint.
Example To single step through a program instead of running at full execution speed, you
must either set a breakpoint while in edit mode (if you have DC 9) or compile
the program without running it.
To compile the program with-
out running it, use the Com-
pile menu option, the
keyboard shortcut F5 or the
toolbar menu button (pictured
to the left of the Compile
menu option).
F7, F8, Alt+F7 and Alt+F8 are
the keyboard shortcuts for
stepping through code. Use F7 if you want to step at the C statement level, but
want to step into calls to debuggable functions. Use F8 instead if you want to
step over function calls.
If the Assembly window is open, the stepping will be done by assembly instruc-
tion instead of by C statement if the feature “Enable instruction level single step-
ping” is checked on the Debugger tab of the Project Options dialog; otherwise,
stepping is done by C statement regardless of the status of the Assembly win-
dow. If you have checked “Enable instruction level single stepping” but wish to
continue to step by C statement when the Assembly window is open, use Alt+F7
or Alt+F8 instead of F7 or F8.