Texas Instruments MSP-FET430PIF, Руководство пользователя

Страница: 21 / 80

www.ti.com
2.3.3 Using Single Step
2.3.4 Using Watch Windows
Using C-SPY
The Run To Cursor operation temporarily requires a breakpoint. Consequently, only N – 1 breakpoints can
be active when Run To Cursor is used if virtual breakpoints are disabled (see FAQ
Debugging #33 ).
If, while processing a breakpoint, an interrupt becomes active, C-SPY stops at the first instruction of the
interrupt service routine (see FAQ
Debugging #26 ).
When debugging an assembler file, Step Over, Step Out, and Next Statement operate like Step Into; i.e.,
the current instruction is executed at full speed.
When debugging an assembler file, a step operation of a CALL instruction stops at the first instruction of
the called function.
When debugging an assembler file, a (true) Step Over a CALL instruction that executes the called function
at full device speed can be synthesized by placing a breakpoint after the CALL and GOing (to the
breakpoint in realtime mode).
When debugging a C file, a single step (Step) operation executes the next C statement. Thus, it is
possible to step over a function reference. If possible, a hardware breakpoint is placed after the function
reference, and a Go is implicitly executed. This causes the function to be executed at full speed. If no
hardware breakpoints are available, the function is executed in non-realtime mode. Step Into is supported.
Step Out is supported.
Within Disassembly mode (View
→
Disassembly), a step operation of a non-CALL instruction executes the
instruction at full device speed.
Within Disassembly mode (View
→
Disassembly), a step operation of a CALL instruction places, if
possible, a hardware breakpoint after the CALL instruction, and then executes Go. The called function
executes at full device speed. If no hardware breakpoint is available prior to the Go, the called function is
executed in non-realtime mode. In either case, execution stops at the instruction following the CALL.
It is only possible to single step when source statements are present. Breakpoints must be used when
running code for which there is no source code (i.e., place the breakpoint after the CALL to the function for
which there is no source, and then Go to the breakpoint in realtime mode).
If, during a single step operation, an interrupt becomes active, the current instruction is completed and
C-SPY stops at the first instruction of the interrupt service routine (see FAQ
Debugging #26 ).
The C-SPY Watch Window mechanism permits C variables to be monitored during the debugging session.
Although not originally designed to do so, the Watch Window mechanism can be extended to monitor
assembler variables.
Assume that the variables to watch are defined in RAM, for example:
RSEG DATA16_I
varword ds 2 ; two bytes per word
varchar ds 1 ; one byte per character
In C-SPY:
1. Open the Watch Window (View
→
Watch).
2. Click Debug
→
Quick Watch.
3. To watch varword, enter in the Expression box:
(__data16 unsigned int *) varword
4. To watch varchar, enter in the Expression box:
(__data16 unsigned char *) varchar
5. Click the Add Watch button.
6. Close the Quick Watch window.
7. For the created entry in the Watch Window, click on the + symbol to display the contents (or value) of
the watched variable.
SLAU138F – June 2004 – Revised March 2007 Development Flow 21
Submit Documentation Feedback