The recommended method of handling unused GPIO is introduced in another topic (Please tell me how to handle unused GPIO pins), but depending on the specifications of the device to be designed, it must be handled with an external pull-up/pull-down. There may be cases.

The optimum Pin mode setting for that case depends on the specifications of the device, but in most cases the following settings are fine.

• input
• input filter

Note that depending on your choice of pullup voltage, it is possible that the IO pin will have voltage before the EFM32 is powered. Since the device may be damaged, please also refer to another topic (Is it okay to input a signal from the outside when the power is not supplied?).