The device can start-up as either
I2C or SPI depending on the 2-level input level sampled on the GPIO1 pin during
POR.
- GPIO1 = 0:
I2C Serial Interface is selected and the
SCS_ADD pin functions as a 3-level input for the I2C address select.
- GPIO1 = 1:
SPI Serial Interface is selected and the
SCS_ADD functions as a SPI chip select.