"Proper" is in the eye of the beholder I guess ... remember that this is an 8-bit part with 4 KB of program space and 256 bytes of RAM. You are probably not im

"Proper" is in the eye of the beholder I guess ... remember that this is an 8-bit part with 4 KB of program space and 256 bytes of RAM. You are probably not implementing a gdb stub on that while still having meaningful resources (memory, peripherals, execution time) left for your an application complex enough to warrant that level of debugging support. :) That said, it seems these cores have some on-chip hardware debugging support. See the data sheet [1] section 30 ("Unified Program and Debug Interface (UPDI)"). Features include: - Memory mapped access to device address space - Unlimited number of user program breakpoints - Two hardware breakpoints - Run-time readout of CPU Program Counter (PC), Stack Pointer (SP), and Status register(SREG) for code profiling - Program flow control (Go, Stop, Reset, Step Into) - Non-intrusive run-time chip monitoring without accessing system registers This interface is the one that is described in the article, and accessed over a single pin on the chip package. I think it sounds pretty neat, makes me want to have a look at AVRs again! :) [1] http://ww1.microchip.com/downloads/en/DeviceDoc/ATtiny406-DataSheet-DS40001976B.pdf http://ww1.microchip.com/downloads/en/DeviceDoc/ATtiny406-Da...