Serial Peripheral Interface

[yugeswar]

Hi team,

             I am trying to work on SPI peripheral on the nordic development board nRF52840. How many SPI compatible ICs are present on the board. And how to identify them?

Thanks.

[Karl Ylvisaker]

Hello,

There is no devices on the nRF52840 DK that uses an SPI interface. The closest thing would be the external memory that uses QSPI, but not SPI. 
You can check this directly in the DK Hardware files.

Best regards,
Karl

[yugeswar]

Thank You Karl.

[Karl Ylvisaker]

No problem at all, I am happy to help! :)

Please do not hesitate to open another ticket if you should encounter any other issues or questions in the future.

Good luck with your development!

Best regards,
Karl

[yugeswar]

Hello Karl,

I am using SDK 16.0 for nRF52840 development board. I have found an example code for SPI in D:\..nRF5 SDK v16.0\examples\peripheral\spi path.

However, like You have mentioned that the MCU is connected to external memory via SPI, which APIs can I use for reading and writing data to the external memory?

thanks.

[Karl Ylvisaker]

Hello,

yugeswar said:

However, like You have mentioned that the MCU is connected to external memory via SPI

This is not quite accurate - I said that the MCU is connected to external memory through QSPI, which is not SPI.
If you would like to test the usage of the external memory mounted on the DK you can check out the QSPI example in the SDK.

Best regards,
Karl

[yugeswar]

Thanks for the reply Karl.

I agree that the external memory is connected to MCU through QSPI. But in the nRF52840_DK_User_Guide,

 https://infocenter.nordicsemi.com/pdf/nRF52840_DK_User_Guide_v1.2.pdf , it is mentioned that both SPI and QSPI are connected to the external memory.

If it is so, and if we configure SPI with the external memory GPIO pins, which APIs can I use to read and write data?

Regards,

Yugeswar

[Karl Ylvisaker]

Hello again, Yungeswar

My apologies, it seems that I misunderstood your intentions earlier.

The answer to your question about which API you could use is indeed either the QSPI peripheral API, or the SPIM peripheral API.
If you would like a reference on how to communicate with the external memory you could look at the Fatfs storage SD Card Example.
If I could ask, however, why is it that you would like to use SPI for the transfers to the external memory, when you could be using QSPI?

The pinout/connection to the external memory could also be helpful for you to take a look at, and it is described in the DKs external memory documentation.

Best regards,
Karl