LPC824, Power Down & PIN Interrupt wakeup issue

[rianzu]

Digital glitch filtering on GPIO inputs it's a nice feature on LPC824.

It's possible to have'it active while using power down mode?

I noticed that once enabled, part will enter into power down but won't be able to wake-up anymore. Probably the clock of digital sampler is turned off (most likely) and the edge that suppose to arrive as wake-up source is not catch. 

Also, it's possible to just wake-up the part and NOT jump to interrupt vector?

(use PIN as wake-up source but not using interrupts for such event)

Thanks,

[kerryzhou]

Hi Rian,

    Thank you for your interest in NXP LPC product, I would like to provide service for you!

1.  It's possible to have  digital glitch filtering active while using power down mode?

    No, as you know, the digital glitch filtering should use the filter clock, and the filter clock is selected from the peripheral clocks, you can get it from the user manual:

But in the power down mode:

   

  You can get that all the peripheral clocks are disabled except for the watchdog timer.

  So, you can't use the digital glitch in power down mode, and you test already verify it.

2. it's possible to just wake-up the part and NOT jump to interrupt vector?

  From low power wake-up conditions in the flowing picture:

You can get that you must enable the NVIC.

  But in the Deep power-down mode,  you can wake up on a pulse on the WAKEUP pin, and don't need to use interrupt.

Wish it helps you!

If you still have question, please let me know!

Have a great day,
Jingjing

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[rianzu]

Hello Jingjing,

I'm not able to wake-up if NVIC entry PININTx is not enabled.

So I guess wake-up glue is tied on NVIC (after) and not on peripheral flag to NVIC (just before it).

My use-case don't need that jump. Just wake-up and continue (resume) from that point.

[kerryzhou]

Hi Rian,

    NVIC is must enabled for waking up from power-down mode:

  Actually, when the Pin interrupt happens, you also need to clear the pin interrupt flag in the according interrupt.

  After the interrupt is exit, then the code will run from the position which below entering the Power down mode.

  Enable NVIC to wakeup the power down mode is the wakeup mechanism.

Wish it helps you!

Have a great day,
Jingjing

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[robin_maeder]

Hello @kerryzhou  and @rianzu 

I am trying to wake up the LPC824 from Deep-sleep or Power-down with an external pin but I can not get it working. I tried it according your comments above. I tried it according to the example lpcxpresso824max_power_mode_switch_lpc from SDK. But it does not work either way.

1. Is it possible to use PINT for waking up the LPC824? In the following post they say that pin interrupt is incapable of waking up the MCU from the Deep-sleep or Power-down on LPC11xx? https://community.nxp.com/t5/LPC-Microcontrollers/How-to-wake-up-the-system-from-deep-sleep-mode-wit...

2. Is there another way or example for waking up with pin interrupt?

@rianzu Maybe you can send me your code snippet that worked for you?

Thank you and best regards.

[kerryzhou]

Hi robin_maeder,

   I do already not support the LPC product now.

   So, if you have any LPC issues, you can create the new question post in the LPC community

https://community.nxp.com/t5/LPC-Microcontrollers/bd-p/lpc

   Then our LPC engineer will help you, thanks a lot for your understanding.

Best Regards,

Kerry