Everything
2.9.3.1 Step into the function (Step In execution)

When the function is called, the program is stopped at the top of the called function.

Click the button on the debug toolbar to perform Step in execution.

Caution 1.

Step In execution cannot be performed for a function that has no debug information.

Caution 2.

If Step in execution is performed for the longjmp function, program execution may not complete and may wait for a time-out.

Caution 3.

[E1] [E20]
No interrupts are accepted during stepped execution. In JTAG communication, resetting is also prohibited during stepped execution.