Allocate gpio pins for UART on the nRF5340

[Hiihtaja]

Hello !

I need for allocate gpio pins for 3rd UART e.g for RX/TX/RTS/CTS on the nRF5340.

Are all pins are equal and I can select any free ones or some limitation exists ?

How I can configure under Zephyr if those pins will be controlled by network core ?

How to configure usage of other peripherals on network core only ?

I mean GPIOTE, RADIO, RTC, TIMER, PPI .

Can west build system create report what peripheral controller from app core or network core ?

Source samples are quite complicate and not so easy to identify what in use and where.

Regards,

Eugene

[Sigurd Hellesvik]

Hi Eugene,

Are all pins are equal and I can select any free ones or some limitation exists ?

See nRF5340 Pin Assignements.

How I can configure under Zephyr if those pins will be controlled by network core ?

See nordic,nrf-gpio-forwarder.

How to configure usage of other peripherals on network core only ?

From nRF5340 Peripherals:

"The application core peripherals are found in Instantiation, and the network core peripherals are found in Instantiation. The application core peripherals are accessible from the network core, but the network core peripherals are not accessible from the application core. For further details, see Memory."

Can west build system create report what peripheral controller from app core or network core ?

I do not understand this question. Can you elaborate?

Regards,
Sigurd Hellesvik

[Hiihtaja]

Hi Sigurd !

So network core by default can access all peripherals like nrf52840 device.

Application - only limited set.

And only for one peripheral, GPIO, I can disable access to some pins from application core.

Is this something like this ?

I mean if I take some libraries and etc. some peripherals might be in use.

So I should look all sources for understand what PPI channels are free for example.

Regards,

Eugene

[Sigurd Hellesvik]

For the core that will not use a peripheral, I suggest that you disable that peripheral.

To do this, use the devicetree. See samples/matter/light_bulb/boards/nrf5340dk_nrf5340_cpuapp.overlay for an example.

Also, look at the nrfx peripheral resource sharing example, and nrfx use example; they might be helpful.

Regards,
Sigurd Hellesvik

[Hiihtaja]

Hi Sigurd !

So I can put all permanent overlays to one of the file

1. Otherwise, if <BOARD>.overlay exists, it will be used, and the build system will stop looking for more files.

2. Otherwise, if app.overlay exists, it will be used.

and they will be permanent for application core

But what about network core in case of multi-image build.

How to specify it, in what folder ?

Regards,

Eugene

[Sigurd Hellesvik]

child_image/<CHILD_IMAGE>.overlay

or child_image/<CHILD_IMAGE>/boards/<BOARD>.overlay

Ref Image-specific variables

Regards,
Sigurd Hellesvik