User guide

Nios II IDE Help System
When Specify Location is off, the New Project wizard always creates a new, valid project
directory.
Q: Why does the source code not display when stepping in the debugger?
A: If you compile a project without the -g compiler option, the IDE cannot display source code
during debug sessions. To add debug information to your project, right-click your project and
then click Properties . Click C/C++ Build. On the Tool Settings tab, expand Nios II
Compiler and click General. Select Default (-g) from the Debug Level list on the right
side.
Q: Why can't I debug systems containing an active watchdog timer?
A: While paused in debug mode, the processor does not stop the watchdog timer. This is a
deliberate choice because in deployed systems the watchdog timer should trigger even if the
processor has hit a break instruction. Unfortunately the paused processor is not able to refresh
the watchdog timer, so the watchdog timer resets the system and your debug connection is
lost. To avoid this, do not enable watchdog timers while debugging.
Q: Why do I see the message "Unable to connect to JTAG UART because another
application is using it" when I try to start a run or debug session?
A: The IDE does not automatically terminate previous run or debug sessions if Allow multiple
active run/debug sessions is on. In this case, you must manually terminate existing
sessions that use the JTAG cable before starting a new session. Alternately, you can click
Preferences on the Window menu, then click Nios II, then turn off Allow multiple active
run/debug sessions.
Q: Why does my project fail to compile after I make changes in SOPC Builder? How
do I get the Nios II IDE to recognize component name changes made in SOPC
Builder?
A: If you change the names of components in the SOPC Builder system, you must update the
system library project to reflect the new component names. Right-click your system library
project and then click Properties. Review the System Library page of the Properties dialog
box to verify that any referenced component names appear correctly, and then rebuild your
system library project. If you renamed the processor in SOPC Builder, then you must recreate
a system library targeted to the system with the new processor. Alternatively, you can delete
the system library project (without deleting the contents) and re-import the project, selecting
the new processor in the process. You might also have to update your application code to
reflect the new component name(s).
Q: Why is the Nios II IDE GUI responsiveness slow?
A: If you have a lot of open projects in the C/C++ Projects view, you can disable the
automatic refresh feature to improve GUI performance. On the Window menu, click
Preferences, expand General, click Workspace, then turn off Refresh automatically. You
can manually refresh the workspace by choosing Refresh on the File menu or pressing F5.
The GUI responsiveness might also be slower while the C/C++ Indexer creates a database of
source and header files when you first start the IDE or after you create a new project. After
creating or building a Nios II project, the source code for the newlib C library, device drivers
and software packages is linked to the altera.components project found in the Nios II
C/C++ Projects view. These links allow the Editor view to display shared code, so you can set
breakpoints in the code during debug.
Note: Anti-virus software can make the process of indexing altera.components
substantially slower.
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