Hardware debugging of AVR microcontrollers is a crucial element of the programming process, enabling precise testing and diagnosis of code issues. Here are some popular methods and tools for hardware debugging for AVR:
debugWIRE is a debugging interface developed by Atmel (now Microchip Technology) for AVR microcontrollers. It enables debugging using a single pin (RESET) and is particularly useful in small microcontrollers that lack many pins. debugWIRE allows setting breakpoints, tracking code execution, and monitoring registers.
JTAG (Joint Test Action Group) is a standard debugging interface that enables full debugging of AVR microcontrollers. JTAG offers advanced features, including code execution tracking, setting breakpoints, monitoring registers, and memory. It is a more advanced tool than debugWIRE but requires more pins.
PDI (Program and Debug Interface) PDI is a debugging interface used in some AVR microcontrollers, such as AVR XMEGA. PDI enables programming and debugging of the microcontroller using two pins. It is a compromise between the simplicity of debugWIRE and the advanced capabilities of JTAG.
Debugging Tools
Microchip Studio: An integrated development environment (IDE) for AVR microcontrollers that supports debugging using debugWIRE, JTAG, and PDI.
AVR-GDB: A version of the classic GDB debugger adapted for AVR microcontrollers. It allows debugging code at the assembler and C/C++ level.
AVRDUDE: A tool for programming AVR microcontrollers that can be used in conjunction with hardware debuggers.
Simulator
Practical Tips
Setting fuses: Before starting debugging, the microcontroller fuses should be properly set to enable the use of debugWIRE or JTAG.
Disconnecting external reset sources: In the case of debugWIRE, all external reset sources should be disconnected to avoid interference.