Some pins on the device are dedicated for a specific purpose. GPIO pin routing and configuration is flexible. Some pins have limitations or recommendations for configuration and use.
| Peripheral | Description |
|---|---|
| UARTE20/21 | Can use any pin on P1. Can connect across power domains to dedicated pins on P2 as described in the notes following this table. |
| SPIM00 | Has dedicated pins on P2. For 32 MHz operation, the pins must be configured using extra high drive E0/E1 configuration in the DRIVE0/1 fields of the PIN_CNF GPIO register. |
| SPIM20/21 | Can use any pins on P1; see Clock pins. Can connect across power domains to dedicated pins on P2 as described in the notes following this table. |
| SPIS20/21 | Can use any pins on P1; see Clock pins. Can connect across power domains to dedicated pins on P2 as described in the notes following this table. |
| TRACE | Has dedicated pins that must be configured using extra high drive E0/E1 configuration in the DRIVE0/1 fields of the PIN_CNF GPIO register. |
| GRTC | Has dedicated pins for clock and PWM output. |
| TAMPC | Has dedicated pins for active shield input and output. |
| FLPR | Uses dedicated pins on P2 for emulated peripherals such as QSPI. |
| RADIO | Uses dedicated pins on P1 for antenna switch control (DFEGPIO for direction finding). |
| NFC | Uses dedicated pins as listed in the pin assignments table for the selected device. These pins are configured as NFC antenna pins from reset. To use the pins for Digital I/O, NFC function must be disabled in the NFCT — Near field communication tag peripheral. |
Cross power-domain use
Select P2 pins can be used for some serial interfaces in the peripheral domain — SPIM, SPIS, and UARTE when the device is in Constant Latency sub-power mode. This is not the most power-efficient way of connecting these serial interfaces, but adds flexibility when designing a circuit board. When setting up the peripheral's PSEL register for cross-domain connections, it must be connected only to the corresponding function listed in the pin assignments table for that package. For example, the peripheral's PSEL.SCK register must use the P2 SCK pin from the pin assignment table. The pin assignments table shows which pins can be configured for cross power-domain connections.
For more information about Constant Latency sub-power mode, see Sub-power modes.