Datasheet

26. DBG - debugWIRE On-chip Debug System
26.1. 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 Non-volatile Memories
26.2. 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 non-volatile memories.
26.3. 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 26-1. The debugWIRE Setup
dW
GND
dW(RESET)
V
CC
1.8 - 5.5V
Atmel ATmega16M1/32M1/64M1 [DATASHEET]
Atmel-8209F-ATmega16M1/32M1/64M1_Datasheet_Complete-10/2016
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