PICkit™ 3 USER’S GUIDE
©
2009 Microchip Technology Inc.
DS51795A-page 15
Chapter 2. Theory of Operation
2.1
INTRODUCTION
A simplified description of how the PICkit 3 programmer/debugger system works is
provided here. It is intended to provide enough information so a target board can be
designed that is compatible with the debugger for both emulation and programming
operations. The basic theory of in-circuit emulation and programming is described so
that problems, if encountered, are quickly resolved.
• PICkit 3 vs. PICkit 2
• Debugger to Target Communication
• Communication Connections
• Debugging
• Requirements for Debugging
• Programming
• Resources Used by the Debugger
2.2
PICkit 3 VS. PICkit 2
The PICkit 3 programmer/debugger system is similar in function to the PICkit 2
in-circuit debugger system. Similarities of the two debuggers include:
• Powered via USB cable to PC
• Provides a programmable voltage power supply
The PICkit 3 differs from the PICkit 2 by providing:
• Extended EE program image space (512 Kbytes)
• True voltage reference
• Increased voltage range (1.8-5V V
DD
; 1.8-14V V
PP
)
2.3
DEBUGGER TO TARGET COMMUNICATION
The debugger system configurations are discussed in the following sections.
Standard ICSP Device Communication
The debugger system can be configured to use standard ICSP communication for both
programming and debugging functions. This 6-pin connection is the same one used by
the PICkit 2 programmer/debugger.
CAUTION
Do not change hardware connections while the PICkit 3 or target is powered.
