SLAU723A October 2017 – October 2018 MSP432E401Y , MSP432E411Y
The I2C interface supports dual address capability for the slave. The additional programmable address is provided and can be matched if enabled. In legacy mode with dual address disabled, the I2C slave provides an ACK on the bus if the address matches the OAR field in the I2CSOAR register. In dual address mode, the I2C slave provides an ACK on the bus if either the OAR field in the I2CSOAR register or the OAR2 field in the I2CSOAR2 register is matched. The enable for dual address is programmable through the OAR2EN bit in the I2CSOAR2 register and there is no disable on the legacy address.
The OAR2SEL bit in the I2CSCSR register indicates if the address that was ACKed is the alternate address or not. When this bit is clear, it indicates either legacy operation or no address match.