Fuse Bytes

Fuse Bytes (AVR® MCU Targets)

When doing drag-and-drop programming, the debugger masks out fuse bits that attempt to disable Unified Program and Debug Interface (UPDI). This means that the UPDI pin cannot be used in its reset or GPIO modes; selecting one of the alternative functions on the UPDI pin would render the device inaccessible without using an external debugger capable of high-voltage UPDI activation.