nRF7002 with external FLASH memory

[alexandre_duch]

Hi,

We are developing a device using the nRF5340 DK and need to add external Flash memory accessible via QSPI with XIP, as the available memory is insufficient due to DFU requirements, which halve the memory available for the application.

Additionally, we need to communicate with an nRF7002 EK to enable the coexistence of Wi-Fi and Bluetooth LE.

1. Is it possible to share the QSPI bus to communicate with both the nRF7002 and the external memory (using XIP)?
2. Is it possible to share an SPI bus to communicate with the nRF7002 and other SPI peripherals?
3. What are the constraints of using SPI compared to QSPI?
4. Do you have sample code I could use as a reference?

[runsiv]

If Hi

I will need to check internally for a few of the questions and get back to you

Is it possible to share the QSPI bus to communicate with both the nRF7002 and the external memory (using XIP)?

From reading a bit on different similiar questions it sounds like it might be possible. However there is not built in support to handle dynamic switching. 

Kenneth gave a reply on this here

According to Jared in this case we have not tested it can not guarantee anything. 

I will however a check internally to see if there has been any change the last year

What are the constraints of using SPI compared to QSPI

Throughput will be major factor for choosing QSPI over SPI. SPI do also not support encryption of the communication while QSPI supports it. However the wifi credentials is stored on the 5340 and only session based derived key is programmed to the 7002, new keys is also generated for every connection so that should not be a big issue. 

Is it possible to share an SPI bus to communicate with the nRF7002 and other SPI peripherals?

I'm checking internally

Do you have sample code I could use as a reference?

If you plan using the 7002 over SPI I would suggest take a look at build samples where 7002ek is used as it uses SPI. Other then that I would recommend checking out the wifi samples in the sdk. Is there anything specific you are after? 

Regards

Runar

[runsiv]

runsiv said:

Is it possible to share an SPI bus to communicate with the nRF7002 and other SPI peripherals?

We have not tested sharing the SPI or the QSPI and as mentioned with the QSPI, you would need some custom hw and sw design to make it work. As it is something we have not tested we don't know what issues could arise. 

Regards

Runar