Microchip Technology MPLAB PICkit 4, User Manual

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3. Operation
A simplified theory of operation of the MPLAB PICkit 4 In-Circuit Debugger system is provided here. It is intended to
provide enough information so that a target board can be designed that is compatible with the debugger for both
debugging and programming operations. The basic theory of in-circuit debugging and programming is discussed so
that problems, if encountered, are quickly resolved.
3.1 Debugger to Target Communication
Important: The MPLAB X IDE software must be installed prior to connecting the MPLAB PICkit 4 In-
Circuit Debugger.
The debugger is connected to the computer via a USB cable for communication and debugger power.
The debugger is connected to the target application for communication and data collection and optional debugger
power.
The debugger system configurations are discussed in the following sections.
DS50002596B-page 18
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2017 Microchip Technology Inc.
CAUTION
Communication Failure.
Do not connect the hardware before installing the software and
USB drivers.
CAUTION
Debugger or Target Damage.
Do not change hardware connections while the debugger or target
is powered.
Note: The MPLAB PICkit 4 In-Circuit Debugger is warrantied for operation using the provided cable. Cables from
other vendors may result in communication errors.
3.1.1 Standard ICSP
™
Device Communication
The debugger system can be configured to use standard ICSP communication connection for both programming and
debugging functions.
Make sure to align the Pin 1 on the debugger to Pin 1 on the target. The programming connector can be inserted into
either:
• A matching connector at the target, where the target device is on the target board ( Figure 3-1 ).
• A standard adapter/header board combo (available as a Processor Extension Pak), which is then plugged into
the target board ( Figure 3-2 ).
For more on standard communication, see Standard Communication .
Operation
©
2020 Microchip Technology Inc.
User Guide
DS50002751D-page 10