3.6 Connecting External Debuggers
Even though there is an on-board debugger, external debuggers can be connected directly to the PIC18F57Q43 Curiosity Nano to program/debug the PIC18F57Q43. The on-board debugger keeps all the pins connected to the PIC18F57Q43 and board edge in tri-state when not actively used. Therefore, the on-board debugger will not interfere with any external debug tools.
CAUTION:  The MPLAB®
            PICkit™ 4 In-circuit Debugger/Programmer is capable of delivering
            high voltage on the MCLR pin. High voltage can permanently
            damage R110. If R110 is
            broken, the on-board debugger can not enter Programming mode of the PIC18F57Q43 and will typically fail at reading the device
            ID.
        
        CAUTION:  To avoid contention
            between the external debugger and the on-board debugger, do not start any
            programming/debug operation with the on-board debugger through MPLAB® X IDE or mass storage programming
            while the external tool is active.
    