QSPI Peripheral Activation Task

[sunbing]

Based on nRF52840 datasheet, to configure the QSPI peripheral, it is necessary to  activate the external flash memory interface using ACTIVATE task. Our problem here is, during flash testing (r/w) periodically, after executing for 2-3 days, we will not get the READY event after issuing ACTIVATE task any more. Retry multiple times (5 times) also no luck. It seems once we fall this situation, we are not able to get out unless restarting the application. So my question is:

1. why we ends up in such situation after few days execution?

2. how to get out of this situation without restarting the whole application?

3. what exactly does this ACTIVATE task do? There are some existing tickets asking about this but the answer is not very clear. Some answers mention nRF will issue clock and read flash status register etc. but we tried to monitor the QSPI bus but no clock is being observed.

Thanks! 

[Hung Bui]

Hi Bing Sun, 

As you can find the information in this case: https://devzone.nordicsemi.com/f/nordic-q-a/28947/what-does-qspi-activate-task-do, the ACTIVATE task request the HFCLK and try to read the status from the external flash. 

We would need to determine the READY task didn't return was because of the QSPI interface on the nRF52 or it's the external flash didn't response. 

Could you try to capture a logic trace of the QSPI communication ? 

You mentioned that you had to restart the application. Did you power reset the whole board or it's only the MCU got reset ?  

Have you tried to trigger a DEACTIVATE task and then ACTIVATE again ? 

How often did you observed the issue  ? It always happened after 2-3 days or only occasionally ? 

[sunbing]

Hi Hung Bui,

Thanks for the reply.

Managed to capture QSPI trace and there is clock observed.

I restart MCU only (thru debugger) without power cycle the board. 

Will try deactivate task then.

Seems it always happens, sometimes 2 days or less, sometimes longer but eventually it will happen.