call IRQ handler while waking up the MCU from SYSTEM OFF mode

RE: call IRQ handler while waking up the MCU from SYSTEM OFF mode

Maunik Patel — Wed, 13 Mar 2019 10:46:22 GMT

Ohk Edvin.

That was my misunderstanding.
Thanks for clearing it.
Now I have some what clear picture (as compared to previous state) of these sleep modes.

Thanks for figuring out my issue.

Thanks a lot Edvin. 🙂

RE: call IRQ handler while waking up the MCU from SYSTEM OFF mode

Edvin — Wed, 13 Mar 2019 09:44:05 GMT

If I am not mistaken, your link refers to WFE and WFI, which are system-on mode. System off mode is a much deeper "sleep mode", where the chip is basically turned off. Any interrupt will restart the application from start.

I think you are mixing up system-on and system-off sleep modes on the nRF.

RE: call IRQ handler while waking up the MCU from SYSTEM OFF mode

Maunik Patel — Wed, 13 Mar 2019 09:21:10 GMT

Hi Edvin,

I got your point and right now implementing it in my project.
Thanks for your time.

Apart from this, I have gone through this link.
Table 9.13 on it have 2 columns named "Wake up" and "ISR Execution".
Some of its rows have YES-YES for both the columns mentioned above.
So I am assuming that we can wake the MCU as well call dedicated IRQ Handler, on a single event, if we fulfill all the conditions mentioned in the table.
Am I missing / misunderstanding some thing here ?

Can you help me to understand the table and achieve my primary goal using such configurations ?
It will also help me to understand Cortex-M0, deeply.

Thank You,
Maunik Patel

RE: call IRQ handler while waking up the MCU from SYSTEM OFF mode

Edvin — Tue, 12 Mar 2019 12:47:41 GMT

Hello,

When you go to system off mode, it is like turning off the chip, but you have set this pin as a wakeup source. When the chip wakes up, it will start from the top of main() again, so this event handler is not set up at this point in time, which is why you don't see this interrupt handler.

If you want to enter the application in a specific state on wakeup, I suggest you check the state of the pin on startup, to see whether it is high or low, either enter in_pin_handler_1 or not, based on the state of this pin.

Best Regards,

Edvin