Datasheet

The I/O pin configurations are described further in this chapter, and summarized in Table 23-2.
23.6.3.1 Pin Configurations Summary
Table 23-2. Pin Configurations Summary
DIR INEN PULLEN OUT Configuration
0 0 0 X Reset or analog I/O: all digital disabled
0 0 1 0 Pull-down; input disabled
0 0 1 1 Pull-up; input disabled
0 1 0 X Input
0 1 1 0 Input with pull-down
0 1 1 1 Input with pull-up
1 0 X X Output; input disabled
1 1 X X Output; input enabled
23.6.3.2 Input Configuration
Figure 23-4. I/O configuration - Standard Input
PULLEN
DIR
OUT
IN
INEN
PULLEN INEN DIR
0 1
0
Figure 23-5. I/O Configuration - Input with Pull
PULLEN
DIR
OUT
IN
INEN
PULLEN INEN DIR
1 1
0
Note: When pull is enabled, the pull value is defined by the OUT value.
23.6.3.3 Totem-Pole Output
When configured for totem-pole (push-pull) output, the pin is driven low or high according to the
corresponding bit setting in the OUT register. In this configuration there is no current limitation for sink or
source other than what the pin is capable of. If the pin is configured for input, the pin will float if no
external pull is connected.
Note: Enabling the output driver will automatically disable pull.
SAM D21 Family
PORT - I/O Pin Controller
© 2018 Microchip Technology Inc.
Datasheet Complete
DS40001882D-page 412