On-chip debugging is a hardware-assisted method for inspecting and controlling software while it runs on a device. It usually connects through debug interfaces built into microcontrollers or chips, letting engineers pause execution, step through code, inspect registers and memory, and watch how firmware behaves in real time. In embedded development, this is far more detailed than print-debugging and is especially useful for timing bugs, hardware faults, and hard-to-reproduce crashes.
In cyber security, on-chip debugging matters because the same access that helps defenders can also help attackers. If a debug port is left enabled in production, an adversary may be able to read secrets from memory, modify firmware, bypass protections, or extract behavior from the device. Good defenses include disabling debug access before shipping, locking interfaces with hardware fuses or authentication, and limiting access to lab-only builds and trusted operators.