The Nu-Link-Pro is a full-functional debugger and programmer with debugging, online/offline programming, and SWD I/O voltage setting functions. As shown as below, the Nu-Link-Pro includes an USB port that can be connected to a computer host, a set of Status LEDs, an offline programming button, a SWD port that can be connected to a target chip for debugging and programming (the voltage level of the SWD port can be adjusted through software as 1.8V, 2.5V, 3.3V, or 5.0V), a set of SWD I/O voltage LEDs and SWD Power Output LEDs.