34.5.1 I/O Lines

To use the SERCOM’s I/O lines, the I/O pins must be configured as direct using the System Configuration registers. (See System Configuration and Register Locking (CFG) from Related Links.) I²C does not operate through PPS. (See the DEVCFG1 configuration bits SCOMn_HSEN in Configuration Bits Fuses and also the CFGCON1 SCOMn_HSEN in CFGCON1(L) register.)

Note: SERCOM2 has only I²C functionality and, therefore, the direct configuration using System configuration register is not required.

When the SERCOM is used in I²C mode, the SERCOM controls the direction and value of the I/O pins. Both PORT control bits PINCFGn.PULLEN and PINCFGn.DRVSTR are still effective. In I²C mode, pull-up resistors are disabled. External pull-up resistors are required for proper function.