3.5.1 Sequence of Operations Leading to Debugging

Given that the Requirements for Debugging are met, set the MPLAB ICD 4 In-Circuit Debugger as the current tool in MPLAB X IDE. Go to (File> Project Properties)to open the dialog, then under “Hardware Tool,” click ICD 4. The following actions can now be performed.

• When Debug > Debug Main Project is selected, the application code is programmed into the device’s memory via the ICSP protocol as described at the beginning of this section.
• A small “debug executive” program is loaded into the memory of the target device. Since some architectures require that the debug executive must reside in program memory, the application program must not use this reserved space. Some devices have special memory areas dedicated to the debug executive. Check your device data sheet for details.
• Special “in-circuit debug” registers in the target device are enabled by MPLAB X IDE. These allow the debug executive to be activated by the debugger. For more information on the device’s reserved resources, see the MPLAB X IDE Help>Tool Help Contents>Hardware Tool Reference Help (Reserved Resources).
• The target device is run in Debug mode.