Microchip Technology MPLAB ICD 5 User Manual page 43

Operation
uses the internal in-circuit debug hardware of the target Flash device to run and test the application
program. These two steps are directly related to MPLAB X IDE operations:
1. Programming the code into the target and activating special debug functions (see the next
section for details).
2. Using the debugger to set breakpoints and run.
For more information, refer to the MPLAB X IDE WebHelp.
If the target device cannot be programmed correctly, the MPLAB ICD 5 will not be able to debug it.
A simplified diagram of some of the internal interface circuitry of the MPLAB ICD 5 is shown in the
figure below. In the figure, Rpu=10 kΩ typical and Ric=4.7 kΩ.
Figure 4-4. Proper Connections for ICSP Programming
For programming, no clock is needed on the target device, but power must be supplied. When
programming, the debugger puts programming levels on VPP/MCLR, sends clock pulses on PGC,
and serial data via PGD. To verify that the part has been programmed correctly, clocks are sent
to PGC and data is read back from PGD. This sequence confirms the debugger and device are
communicating correctly.
4.4.2.1 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 ICD 5 In-Circuit Debugger from functioning.
User Guide DS-50003529B - 43
© 2023 Microchip Technology Inc. and its subsidiaries