Which pins to choose for NAND flash ?

[VinuGopalakrishnan]

Hi, I would like to interface an Alliance NAND flash to NRF5340. The flash supports SPI interface. Which set of pins will be a better choice and why ?

I am planning to use nrfx spim drivers and would like max speed.

SET #1 (using high speed SPI)

P0.08 SCK for SPIM4

P0.09 MOSI for SPIM4

P0.10 MISO for SPIM4

P0.11 CSN for SPIM4

P0.12 DCX for SPIM4

SET #2 (QSPI pins of nrfdk)

P0.17

P0.15

P0.13

P0.18

P0.14

P0.16

regards,

Vinu

[runsiv]

Hi

Are you planing to use SPI or QSPI? You have found the correct pins which has the highest SPI speed and the pins for QSPI. QSPI is faster but without any more knowledge about the flash I can't say if it support QSPI or not. Do you plan to run any other peripheral that might need QSPI or XiP? 

I would also pay attention to that there is an errata regarding QSPI and radio desegregation on the 5340, you can see Simons reply regarding it here https://devzone.nordicsemi.com/f/nordic-q-a/113346/nrf5340-qspi-errata-mitigation?ReplyFilter=Answers&ReplySortBy=Answers&ReplySortOrder=Descending and you can find the errata her https://docs.nordicsemi.com/bundle/errata_nRF5340_Rev1/page/ERR/nRF5340/Rev1/latest/anomaly_340_133.html

The errata is only if you read/write while transmitting. 

Regards

Runar

[VinuGopalakrishnan]

We are not planning to use QSPI as we have chosen a SPI NAND flash (AS5F18G04SND). High data rate is a requirement.

[runsiv]

Then it looks good to me, I do however see that the flash support QSPI so that would have been the fastest. What is your speed requirement? 

Regards

Runar

[VinuGopalakrishnan]

Yes, the flash has QSPI support but i have learnt from some posts in dev zone that the QSPI driver of NRF is hardcoded for NOR flash and hence cannot be used to interface a QSPI NAND flash.

[runsiv]

I'm sorry but I need to check if it will work NAND flash. Please see this case 

It might work but I don't think we have any samples for it. Also what is "high" speed? 

Edit: it looks like the NAND support is not yet merged into Zephyr as you can see here https://github.com/zephyrproject-rtos/zephyr/pull/50690 

Regards

Runar