7 I2C Interface
The I2C Interface uses the SDA and SCL pins to indicate various I/O states to the ATECC608A-TNGLoRaWAN. This interface is designed to be compatible at the protocol level with the Microchip AT24C16 Serial EEPROM operating at 1 MHz.
The SDA pin is normally pulled high with an external pull-up resistor because the ATECC608A-TNGLoRaWAN includes only an open-drain driver on its output pin. The bus master may either be open-drain or totem pole. In the latter case, it should be tri-stated when the ATECC608A-TNGLoRaWAN is driving results on the bus. The SCL pin is an input and must be driven both high and low at all times by an external device or resistor.