5.3 P1 port
5.3.1 P1 port description
P1 is an 8-bit I/O port. P1 control registers consist of P1 data register (P1), P1 direction register (P1IO),
debounce enable register (P15DB), P1 pull-up resistor selection register (P1PU), and P1 open-drain
selection register (P1OD). Refer to the port function selection registers for the P1 function selection.
5.3.2 Register description for P1
P1 (P1 Data Register): 88H