User manual

Operation
2013 Microchip Technology Inc. DS52116A-page 23
2.5.5 Circuits That Will Prevent the Debugger From Functioning
Figure 2-5 shows the active debugger lines with some components that will prevent the
PICkit 3 debugger system from functioning.
FIGURE 2-5: IMPROPER CIRCUIT COMPONENTS
In particular, these guidelines must be followed:
Do not use pull-ups on PGC/PGD – they will disrupt the voltage levels, since
these lines have 4.7 k pull-down resistors in the debugger.
Do not use capacitors on PGC/PGD – they will prevent fast transitions on data
and clock lines during programming and debug communications.
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.