User manual

PICkit™ 3 USER’S GUIDE

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 VPP)

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.