Datasheet

30. debugWIRE On-chip Debug System

30.1 Features

• Complete Program Flow Control

• Emulates All On-chip Functions, Both Digital and Analog, except RESET Pin

• Real-time Operation

• Symbolic Debugging Support (Both at C and Assembler Source Level, or for Other HLLs)

• Unlimited Number of Program Break Points (Using Software Break Points)

• Non-intrusive Operation

• Electrical Characteristics Identical to Real Device

• Automatic Configuration System

• High-speed Operation

• Programming of Nonvolatile Memories

30.2 Overview

The debugWIRE on-chip debug system uses a wire with bi-directional interface to control the program

flow and execute AVR instructions in the CPU and to program the different nonvolatile memories.

30.3 Physical Interface

When the debugWIRE Enable (DWEN) bit is programmed to '0' and Lock bits are unprogrammed ('1'), the

debugWIRE system within the target device is activated. The RESET port pin is configured as a wire-

AND (open-drain) bi-directional I/O pin with pull-up enabled and becomes the communication gateway

between target and emulator.

Figure 30-1. The debugWIRE Setup

GND

dW(RESET)

1.8 - 5.5V

ATmega328PB

debugWIRE On-chip Debug System

Datasheet Complete

DS40001906C-page 364