ATmega88PA Automotive Atmel Corporation, ATmega88PA Automotive Datasheet - Page 267

• Manufacturer Part Number: ATmega88PA Automotive
• Manufacturer: Atmel Corporation

25. debugWIRE On-chip Debug System
25.1
25.2
25.3
9223B–AVR–09/11
Features
Overview
Physical Interface
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The debugWIRE On-chip debug system uses a One-wire, bi-directional interface to control the
program flow, execute AVR instructions in the CPU and to program the different non-volatile
memories.
When the debugWIRE Enable (DWEN) Fuse is programmed and Lock bits are unpro-
grammed, 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 25-1. The debugWIRE Setup
Figure 25-1
tor connector. The system clock is not affected by debugWIRE and will always be the clock
source selected by the CKSEL Fuses.
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
Atmel ATmega48PA/88PA/168PA [Preliminary]
shows the schematic of a target MCU, with debugWIRE enabled, and the emula-
dW
GND
dW(RESET)
VCC
1.8 - 5.5V
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