nrf52840 pin select for peripherals such as UART, SPI etc

[Samno]

I am new to designing with Nordic microcontrollers. I am at the point in my design where I am laying out connections to the microcontroller and setting up which pins will use UART, SPI, etc. In reading the datasheet, it seems on the nrf52840 that any pin can be assigned to be MISO, MOSI, SCLK, UART RX, UART TX, etc. Am I reading this correctly? It is very different from other microcontrollers I have used in the past where only certain pins could be MOSI, MISO etc. Being allowed to map any pin to any peripheral certainly makes my life easier as a designer, so I just want to make sure I understand this correctly before getting too far along in my design. So where we see a register like this one for the UART TX pin, where you can map TX to any pin using this register, am I correct in my understanding here?

[AMarch01]

Thats what I take away from the description. I would get the latest errata to make sure there are no pins that don't work as well as others.

Whatever you chose, be sure to create an appropriate device tree overlay that moves the pin definitions so the drivers can correctly assign the pins for you.

There should be a design guide for this somewhere, but I believe just to keep things easy, some people just copy paste the nrf52840-dk reference design. I would, just so examples would work on the first try.... that and make sure you have the crystals in the design.

[SwRa]

HI Sam,

Yes, that is right. Any available pins can be used.. You just need to make sure that the pins are free before assigning them. See here for the pin assignement: https://docs.nordicsemi.com/bundle/ps_nrf52840/page/pin.html 

Best Regards,

Swathy

[AMarch01]

From the page on pin assignments, I would pay attention to any that are low frequency only. I would think 10khz would be a heck of a slow down for SPI.