17.3.1 Initialization
After Reset, all outputs are tri-stated, and digital input buffers enabled even if there is no clock running.
The following steps are all optional when initializing PORT operation:
- Enable or disable the output driver for
pin Pxn by respectively writing ‘
1’ to bit n in the PORTx.DIRSET or PORTx.DIRCLR register - Set the output driver for pin Pxn to
high or low level respectively by writing ‘
1’ to bit n in the PORTx.OUTSET or PORTx.OUTCLR register - Read the input of pin Pxn by reading bit n in the PORTx.IN register
- Configure the individual pin configurations and interrupt control for pin Pxn in PORTx.PINnCTRL
Important: For lowest power
consumption, disable the digital input buffer of unused pins and pins that are used as
analog inputs or outputs.
Specific pins, such as those used to connect a debugger, may be configured differently, as required by their special function.