The In Circuit Debug mode of the chip allows a software utility (running on a PC) to communicate with and control the execution of a PIC CPU.This facility is only available for some PICs and needs to use dedicated I/O pins. The In Circuit Debug mode attribute is used to enable the mode and assign the debug mode communication function to the predefined I/O pins.
This attribute should only be enabled if the PIC is situated in a debug circuit which is under the control of debug software running in a PC.