How to configure QSPI into Deep power down mode while using XiP.

[AR Jadhav]

Hello,

I am using nRF5340 with nrf v2.7.99-cs2.

We have interfaced External flash MX25R over nRF5340's QSPI channel. We are using XiP as well and some part of code lies on external flash. We need to put external flash to deep sleep mode using QSPI when code from external flash will not be executed in our applications low power mode. 

I tried to use pm_device_action_run(flash_dev, PM_DEVICE_ACTION_SUSPEND) and put flash to sleep so that it consumes less current, but I am getting Flash busy error. Can you please help me with a solution so that I can put flash in sleep mode when not executing from external flash under XiP.

Thanks in advance,

Akshay

[Simonr]

Hi

First off, I see that you're on one of the "chip sampling" releases of the nRF Connect SDK and not an official release, so I'd strongly suggest you move to one of the more stable releases. v2.8.0, 2.9.0, or 3.1.0 for example.

What function exactly is it that reports the Flash busy error in your project? Can you upload your config and device tree files so we can get a better look at how your project is set up? Are you working on an nRF5340 DK or a custom board?

We had a similar issue in the past, when specifically using the spi_nor driver for external flash, where the solution was to send the DPD exit command prior to the SPI NOR driver initializing. Note that the DPD cotnrol then will be missing.

Best regards,

Simon

[AR Jadhav]

Hello Simon,

Thanks for your reply.

Please find the required information attached.

1. We are working on custom board

2. Attached zephyr.dts file

3. Also attached autoconf.h file

8507.zephyr.dtsautoconf_.h

[Simonr]

Hi

Again, I'd strongly recommend you move to a stable NCS release. Please share what function reports the flash busy error. Did you try changing when you send the DPD exit command.

Best regards,

Simon

[AR Jadhav]

Hello Simon,

Thanks for your response.

We are planning to move on stable NCS release in near future mean while below is the function which gives flash busy error.

pm_device_action_run(flashdevice, PM_DEVICE_ACTION_SUSPEND);

 

About changing the DPD command location, I tried to use the DPD command from different locations but as I am using XiP, I am not able to put flash in power down mode.

Thanks,

Akshay

[Simonr]

Hi

The flash busy error is caused by the flash device still running some operations when you call the pm_device_action_run-> suspend function. You need to make sure there are no flash operations ongoing and wait for any transactions to complete before calling this function. If your application is performing asynchronous operations, make sure to synchronize and confirm the device is idle before suspending. Please refer to the Zephyr API here: https://docs.nordicsemi.com/bundle/zephyr-apis-latest/page/group_subsys_pm_device.html 

Best regards,

Simon