33.3.2.1 UPDI Enabling

Depending on how the application has configured the UPDI pin, one of the following two methods can be used to enable the UPDI:

• One-Wire Enable - This method requires the UPDI pin to be configured in UPDI function mode by setting the UPDIPINCFG bit in the Pin Configuration (FUSE.PINCFG) register to ‘1’.
• HV Override of UPDI Pin - This method is used if the UPDI pin is configured in GPIO mode (the UPDIPINCFG bit in Pin Configuration (FUSE.PINCFG) is set to ‘0’). Applying an HV pulse on RESET will reconfigure the UPDI pin to UPDI function mode, thereby overriding the configuration in the Pin Configuration (FUSE.PINCFG) fuse.