Specifications

CAVR-4
Part1. Using the compiler
The CLIB runtime environment
91
C-SPY runtime interface
The low-level debugger interface is used for communication between the application
being debugged and the debugger itself. The interface is simple: C-SPY will place
breakpoints on certain assembler labels in the application. When code located at the
special labels is about to be executed, C-SPY will be notified and can perform an action.
THE DEBUGGER TERMINAL I/O WINDOW
When code at the labels ?C_PUTCHAR and ?C_GETCHAR is executed, data will be sent to
or read from the debugger window.
For the
?C_PUTCHAR routine, one character is taken from the output stream and written.
If everything goes well, the character itself is returned, otherwise
-1 is returned.
When the label
?C_GETCHAR is reached, C-SPY returns the next character in the input
field. If no input is given, C-SPY waits until the user has typed some input and pressed
the Return key.
To make the Terminal I/O window available, the application must be linked with the
XLINK option With I/O emulation modules selected. See the AVR® IAR Embedded
Workbench™ IDE User Guide.
TERMINATION
The debugger stops executing when it reaches the special label ?C_EXIT.
Checking module consistency
For information about how to check module consistency, see Checking module
consistency, page 77 in the chapter The DLIB runtime environment.