To single-step program execution
On the Debug menu, click Step Into.
Tip
You can also press the shortcut key, F11, to single-step.
Note
When single-stepping certain instructions such as HALT, LDIR, CPDR and other block repeat instructions, the program counter (PC) will not advance until the required number of interations of the instruction has been executed. If you want to step past block repeat instructions immediately, use the Step Over option.