4.7.2.1 ICSP Circuits That Will Prevent a Debug Tool From Functioning

The figure below shows the active debugger lines with some components that will prevent the MPLAB PICkit 5 In-Circuit Debugger from functioning.

Figure 4-5. Improper Circuit Components

In particular, these guidelines must be followed:

  • Do not use pull-ups on PGC/PGD – they could disrupt the voltage levels.
  • Do not use capacitors on PGC/PGD – they will prevent fast transitions on data and clock lines during programming and debugging communications, and slow programming times.
  • Do not use capacitors on MCLR – they will prevent fast transitions of VPP. A simple pull-up resistor is generally sufficient.
  • Do not use diodes on PGC/PGD – they will prevent bidirectional communication between the debugger and the target device.