Where lines of source code comprise several assembly instructions, the red box does not move from the source line until all instructions for that line of source have been executed.

If a breakpoint is hit when stepping, then the breakpoint might be activated if the breakpoint conditions are met during the step operation.

The run state in the Code window status bar indicates Waiting when a stopped processor is in the middle of a synchronized multiple step operation, and it is waiting for another processor to stop before it continues with the multiple step.