Epson S5U1C17001C, Manual

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S5U1C17001C ManUal
EPSOn
3-41
(C COMPilEr PaCkagE fOr S1C17 faMily) (Ver. 1.5.0)
3 SOfTWarE DEVElOPMEnT PrOCEDUrES
3
SoftDev
If the [Local Variables] window is still open, you can verify that the variable '
j
' increments each time the pro-
gram breaks. Similarly, you can verify that the variable '
i
' displayed in the [Watch Expressions] window incre-
ments every other time the program is run, indicating that the program operates exactly as expected.
Step 67
: Click the [Breakpoints] button.
Examine the [Breakpoints] window. The information on the breakpoint we set above is displayed in it, although
no information was displayed there earlier. The check mark shown at the beginning of the information means
that the breakpoint is currently active. When the check box is unselected, the breakpoint is temporarily dis-
abled: The next time the program is run, it will no longer halt at the position at which it halted earlier. Selecting
the check box reenables the breakpoint.
Step 68
: Click on the
n
mark that is displayed in the [Source] window to turn it off.
This clears the breakpoint.
When the
n
mark disappears, the line is marked with "-" back again. This "-" mark means that the line can be
set to be a breakpoint. The lines lacking this mark are source lines not converted to actual executable instruc-
tions when the source was compiled and assembled. No breakpoints can be set in these lines.
In addition, other break facilities are available, including a temporary break effective only once the program is
run. Discussions of these break facilities are omitted here. For detailed information on break facilities, refer to
Section 10.6.6, "Break Functions".
If any problem in program behavior is detected, the program operation should be verified with greater care.
As the last step of the tutorial, we will proceed through the program by executing one source line at a time.
To proceed through the program step-by-step
Step 69 : Click the [Step] button in the toolbar.
The source line highlighted in green in the [Source] window (the line at which the current PC address exists) is
executed, and the highlighting moves to the next source line to be executed.
By repeating Step 69, we can execute the program one step or one source line at a time. If the program has no
problems, you will see that the displayed register values, etc. change correctly at each step.
The [Step] button executes the program one source line at a time. To execute the program one instruction (mne-
monic) at a time, use the [Step Asm Inst] button.
[Step Asm Inst] button
Step 70
: Click the [Next] button in the toolbar.
Repeat Step 70 to verify differences between this and the [Step] button in the [Source] window.
When the program is run with the [Next] button, you will see that although the function
sub()
was skipped,
the value of the variable '
i
' is updated, indicating that the instructions in the function have all been executed.
The [Next] button operates in basically the same way as the [Step] button, except that the [Next] button skips
functions and subroutines (i.e., executes a function or subroutine as one step, without stopping at every instruc-
tion). If you do not need to debug the subroutines instruction by instruction, use the [Next] button instead.