the signal pins of D pins are converted between 3.3 V of Arduino and 5 V of connected device both ways (input or output)
The device I'm using is a Maxim DS3431 1-wire EEPROM. It can accept up to 5.25V. Do I understand correctly that by connecting it to 5V and the shield's signal wire (e.g. D0 pin1) to the EEPROM's signal pin, the shield will convert the signal 5V voltage to 3.3V for the MKR board?