Up to four 8-bit I/O ports are implemented:
Configuration of Digital I/Os After BOR Reset
To prevent any cross currents during start-up of the device, all port pins are high-impedance with Schmitt triggers, and their module functions disabled. To enable the I/O functionality after a BOR reset, the ports must be configured first and then the LOCKLPM5 bit must be cleared. For details, see the Configuration After Reset section of the Digital I/O chapter in the MSP430FR58xx, MSP430FR59xx, and MSP430FR6xx Family User's Guide.