SLAU723A October 2017 – October 2018 MSP432E401Y , MSP432E411Y
The GPIO Direction (GPIODIR) register (see Section 17.5.2) is used to configure each individual pin as an input or output. When the data direction bit is cleared, the GPIO is configured as an input, and the corresponding data register bit captures and stores the value on the GPIO port. When the data direction bit is set, the GPIO is configured as an output, and the corresponding data register bit is driven out on the GPIO port.