AVR debug

Atmel was subsumed by Microchip Technology in 2016
Atmel-ICE
	a development hardware
	supports JTAG, SWD, PDI, TPI, aWire, SPI, debugWIRE, UPDI interfaces
AVR dragon
	a development hardware
	perform a symbolic debug on all devices with OCD with SPI, JTAG, PDI (selected devices), high voltage serial programming, parallel programming, aWire modes
	supports debugging using SPI, JTAG, PDI interfaces
JTAG
	Joint Test Action Group
	IEEE Standard 1149.1-1990
TAP
	Test Access Port
	core of JTAG
ICE
	In-circuit emulation
aWire
	make use of the RESET wire of the AVR device to allow programming and debugging functions
ISP
	In-System Programming
	not a protocol
	generic technology
	AVR use SPI for ISP
ICSP
	In-Circuit Serial Programming
	an enhanced ISP technique
SPI
	Serial Peripheral Interface
PDI
	Program and Debug Interface
	Atmel proprietary interface for external programming and on-chip debugging of the device
debugWIRE
	a serial communications protocol designed by Atmel
	used for on-chip debugging of AVR
HVSP
	High Voltage Serial Programming
TPI
	Tiny Programming Interface
UPDI
	Unified Program and Debug Interface
	Microchip proprietary interface for external programming and on-chip debugging of a device
OpenOCD
	provide debugging, in-system programming and boundary-scan testing for embedded target devices
	support for avr is preliminary and incomplete
GDB server
	GDB stub < GDB server < GDB
	separate from my program
	almost a GDB able to run or attach a process
	communicate with host GDB by GDB remote serial protocol
GDB remote serial protocol
	used by GDB server and GDB stub
	communicate over serial device, tcp, etc.
GDB stub
	included in and linked with my program
	communicate with host GDB by GDB remote serial protocol
avr stub
	GDB stub implementation for avr
AVaRICE
	a program mediates between host and avr target
	communicate with host using GDB serial protocol
	communicate with avr target via JTAG
	implement GDB remote serial protocol
simavr
	a lean, mean and hackable AVR simulator
	implement GDB remote serial protocol
PlatformIO
	an IDE built top of vscode
avrdude
	host application
	a program for downloading and uploading the on-chip memories of Microchip’s AVR microcontrollers

developed only for avr / implementation of standard or general(3rd party available) specification for avr
running at host(maybe linux amd64) / target(avr 8-bit mcu)
host software / target software / physical hardware