XIP for nRF5340+nRF7002 running Matter

[Winston A]

Hi,

We are developing a device using nRF5340+nRF7002 running Matter. The problem we have is the code size which is around 900KB when Matter is enabled.
This leaves us with a very tight code space for our application. Is using XIP a recommended solution to increase code space? Using XIP, is there a reduction in the performance as compared to using the internal flash? Thanks.

[AHaug]

Hi,

You are right, the footprint of Matter + wifi applications are rather large. 

There are however some things you can do to improve your flash, and one of them are Wifi firmware patch relocation https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/device_guides/nrf70/fw_patches_ext_flash.html. 

The Matter documentation regarding optimizing a Matter application is also a useful tool: https://docs.nordicsemi.com/bundle/ncs-latest/page/nrf/protocols/matter/getting_started/memory_optimization.html 

. Is using XIP a recommended solution to increase code space?

XiP is supported and an option that you could investigate, but it will cause higher current consumption due to the need to power on and off the qspi and external flash during operation meaning that this is not suited for battery operated devices.

Using XIP, is there a reduction in the performance as compared to using the internal flash?

Yes, the external flashes are typically slower.  It is not recommended to put any timing critical code (such as interrupts) on the external flash for execution through XiP due to the slower operation speed. You as a developer will have to control every instance in your code to make sure that what you place on the external flash for XiP usage.

Kind regards,
Andreas