ATA8741 ATMEL Corporation, ATA8741 Datasheet - Page 173

• Manufacturer Part Number: ATA8741
• Manufacturer: ATMEL Corporation

26. debugWIRE On-chip Debug System
26.1
26.2
26.3
9140B–INDCO–07/09
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 unprogrammed,
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 commu-
nication gateway between target and emulator.
Figure 26-1. The debugWIRE Setup
Figure 26-1 on page 173
the emulator 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
dW
shows the schematic of a target MCU, with debugWIRE enabled, and
GND
dW(RESET)
VCC
1.8 - 5.5V
ATA8741
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