We have previously used nRF52840 and for the latest iteration of our board design we are updating to use nRF54L15.
We are aware that for nRF52840 we could map any pin to any function however for nRF54L15 we must use specific pins for some function (e.g. clock signals).
We require 3 SPI interfaces and our design is currently intending to configure nRF54L15 as follows:
SPIM/SPIS00
SCK : P2.01
SDO : P2.08
SDI : P2.09
CS : P2.10
SPIM/SPIS20
SCK : P1.12
SDO : P1.13
SDI : P1.14
CS : P1.04
SPIM/SPIS21
SCK : P1.08
SDO : P1.07
SDI : P1.10
CS : P1.06
For one of our SPI interfaces (SPIS21) we do not require SDI (P1.10) and would like to use this as a GPIO (input) signal as we have maxed out the available pins.
In our pinctrl.dtsi file it is possible to only configure the pins we need, for example we can change:
group1 { psels = <NRF_PSEL(SPIM_MOSI, 1, 7)>, <NRF_PSEL(SPIM_MISO, 1, 10)>, <NRF_PSEL(SPIM_SCK, 1, 8)>; };
group1 { psels = <NRF_PSEL(SPIM_MOSI, 1, 7)>, <NRF_PSEL(SPIM_SCK, 1, 8)>; };